Merge pull request #20 from naver/dev-translation

comment cleanup and English translation

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/AgentClassLoader.java

@@ -80,9 +80,9 @@ public class AgentClassLoader {
                     Constructor<?> constructor = bootStrapClazz.getConstructor(String.class, String.class, Instrumentation.class, ProfilerConfig.class);
                     return constructor.newInstance(agentPath, agentArgs, instrumentation, profilerConfig);
                 } catch (InstantiationException e) {
-                    throw new BootStrapException("boot create fail. Caused:" + e.getMessage(), e);
+                    throw new BootStrapException("boot create failed. Error:" + e.getMessage(), e);
                 } catch (IllegalAccessException e) {
-                    throw new BootStrapException("boot method invoke fail. Caused:" + e.getMessage(), e);
+                    throw new BootStrapException("boot method invoke failed. Error:" + e.getMessage(), e);
                 }
             }
         });
@@ -96,7 +96,7 @@ public class AgentClassLoader {
             } else {
                 agentClassName = agent.getClass().getName();
             }
-            throw new BootStrapException("Invalid AgentType. boot fail. AgentClass:" + agentClassName);
+            throw new BootStrapException("Invalid AgentType. boot failed. AgentClass:" + agentClassName);
         }
     }
 
@@ -105,7 +105,7 @@ public class AgentClassLoader {
         try {
             return this.classLoader.loadClass(bootClass);
         } catch (ClassNotFoundException e) {
-            throw new BootStrapException("boot class not found. bootClass:" + bootClass + " Caused:" + e.getMessage(), e);
+            throw new BootStrapException("boot class not found. bootClass:" + bootClass + " Error:" + e.getMessage(), e);
         }
     }
 
@@ -125,9 +125,9 @@ public class AgentClassLoader {
                 try {
                     return findMethod.invoke(agentBootStrap, args);
                 } catch (InvocationTargetException e) {
-                    throw new BootStrapException(findMethod.getName() + "() fail.  Caused:" + e.getMessage(), e);
+                    throw new BootStrapException(findMethod.getName() + "() failed. Error:" + e.getMessage(), e);
                 } catch (IllegalAccessException e) {
-                    throw new BootStrapException("boot method invoke fail. Caused:" + e.getMessage(), e);
+                    throw new BootStrapException("boot method invoke failed. Error:" + e.getMessage(), e);
                 }
             }
         });
@@ -138,7 +138,7 @@ public class AgentClassLoader {
         try {
             return clazz.getDeclaredMethod(method, type);
         } catch (NoSuchMethodException e) {
-            throw new BootStrapException("(" + method + ") boot method not found. Caused:" + e.getMessage(), e);
+            throw new BootStrapException("(" + method + ") boot method not found. Error:" + e.getMessage(), e);
         }
     }
 

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/ClassPathResolver.java

@@ -170,7 +170,7 @@ public class ClassPathResolver {
         try {
             return uri.toURL();
         } catch (MalformedURLException e) {
-            logger.log(Level.WARNING, file.getName() + ".toURL() fail. Caused:" + e.getMessage(), e);
+            logger.log(Level.WARNING, file.getName() + ".toURL() failed. Error:" + e.getMessage(), e);
             return null;
         }
     }

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/PinpointBootStrap.java

@@ -95,13 +95,13 @@ public class PinpointBootStrap {
             List<URL> libUrlList = resolveLib(classPathResolver);
             AgentClassLoader agentClassLoader = new AgentClassLoader(libUrlList.toArray(new URL[libUrlList.size()]));
             agentClassLoader.setBootClass(BOOT_CLASS);
-            logger.info("pinpoint agent start.");
+            logger.info("pinpoint agent starting...");
             agentClassLoader.boot(classPathResolver.getAgentDirPath(), agentArgs, instrumentation, profilerConfig);
-            logger.info("pinpoint agent start success.");
+            logger.info("pinpoint agent started normally.");
             changeLoadState(BOOT_STRAP_LOAD_STATE_COMPLETE);
         } catch (Exception e) {
             // unexpected exception that did not be checked above
-            logger.log(Level.SEVERE, ProductInfo.CAMEL_NAME + " start fail. Caused:" + e.getMessage(), e);
+            logger.log(Level.SEVERE, ProductInfo.CAMEL_NAME + " start failed. Error:" + e.getMessage(), e);
             changeLoadState(BOOT_STRAP_LOAD_STATE_ERROR);
             logPinpointAgentLoadFail();
         }
@@ -115,7 +115,7 @@ public class PinpointBootStrap {
     private static void logPinpointAgentLoadFail() {
         final String errorLog =
             "*****************************************************************************\n" +
-            "* PinpointAgent load fail\n" +
+            "* Pinpoint Agent load failure\n" +
             "*****************************************************************************";
         System.err.println(errorLog);
     }
@@ -126,7 +126,7 @@ public class PinpointBootStrap {
             changeLoadState(BOOT_STRAP_LOAD_STATE_LOADING);
         } else {
             if (logger.isLoggable(Level.SEVERE)) {
-                logger.severe("pinpoint-bootstrap already started. skip agent loading. loadState:" + exist);
+                logger.severe("pinpoint-bootstrap already started. skipping agent loading. loadState:" + exist);
             }
             return true;
         }

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/config/ProfilerConfig.java

@@ -67,12 +67,12 @@ public class ProfilerConfig {
             return new ProfilerConfig(properties);
         } catch (FileNotFoundException fe) {
             if (logger.isLoggable(Level.WARNING)) {
-                logger.log(Level.WARNING, pinpointConfigFileName + " file is not exists. Please check configuration.");
+                logger.log(Level.WARNING, pinpointConfigFileName + " file does not exist. Please check your configuration.");
             }
             throw fe;
         } catch (IOException e) {
             if (logger.isLoggable(Level.WARNING)) {
-                logger.log(Level.WARNING, pinpointConfigFileName + " file read error. Cause:" + e.getMessage(), e);
+                logger.log(Level.WARNING, pinpointConfigFileName + " file I/O error. Error:" + e.getMessage(), e);
             }
             throw e;
         }
@@ -562,7 +562,7 @@ public class ProfilerConfig {
 
     // for test
     void readPropertyValues() {
-        // TODO : use  Properties's defaultvalue instead of using temp variable.
+        // TODO : use Properties's default value instead of using a temp variable.
         final ValueResolver placeHolderResolver = new PlaceHolderResolver();
 
         this.profileEnable = readBoolean("profiler.enable", true);

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/context/AsyncTrace.java

@@ -69,6 +69,6 @@ public interface AsyncTrace {
 
     void recordDestinationId(String destinationId);
 
-    // TODO: final String... endPoint로 받으면 합치는데 비용이 들어가 그냥 한번에 받는게 나을것 같음.
+    // TODO: final String... an aggregated input needed so we don't have to sum up endPoints
     void recordEndPoint(String endPoint);
 }

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/context/RecordableTrace.java

@@ -80,10 +80,11 @@ public interface RecordableTrace {
     void recordParentApplication(String parentApplicationName, short parentApplicationType);
 
     /**
-     * WAS_A -> WAS_B 호출 관계일 때 WAS_B에서 WAS_A가 보내준 호출 정보를 통해 자기 자신의 정보를 추출하여 저장
-     * 이 데이터는 서버맵에서 WAS끼리 호출관계를 알아낼 떄 필요하다.
      * 
-     * @param host host 값은 WAS를 호출한 URL상의 host를 가져와야 한다.
+     * when WAS_A sends a request to WAS_B, WAS_A stores its own data through parameters sent by WAS_B.
+     * This data is needed to extract caller/callee relationship.
+     * 
+     * @param host (we need to extract hostname from the request URL)
      * 
      *
      */

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/context/TraceContext.java

@@ -30,7 +30,7 @@ public interface TraceContext {
     Trace currentTraceObject();
 
     /**
-     * sampling rate를 추가적으로 확인해야 되는 trace를 리턴한다.
+     * return a trace whose sampling rate should be further verified
      * @return
      */
     Trace currentRawTraceObject();

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/instrument/InstrumentException.java

@@ -17,6 +17,7 @@
 package com.navercorp.pinpoint.bootstrap.instrument;
 
 // TODO 추후 별도 계층구조가 필요하면 분화 필요.
+// TODO Separate this class when hierarchical layers are needed
 /**
  * @author emeroad
  */

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/interceptor/ByteCodeMethodDescriptorSupport.java

@@ -17,7 +17,8 @@
 package com.navercorp.pinpoint.bootstrap.interceptor;
 
 /**
- * precompile level의 methodDescriptor를 setting 받을수 있게 한다.
+ * this enables assigning "precompiled" methodDescriptor 
+ * 
  * @author emeroad
  */
 public interface ByteCodeMethodDescriptorSupport {

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/interceptor/InterceptorRegistry.java

@@ -93,7 +93,7 @@ public class InterceptorRegistry {
     SimpleAroundInterceptor getSimpleInterceptor0(int key) {
         SimpleAroundInterceptor interceptor = simpleIndex[key];
         if (interceptor == null) {
-            // 로직이 잘못되었을경우  에러가 발생하지 않도록 더미를 리턴.
+            // return DUMMY upon wrong logic
             return DUMMY;
         }
         return interceptor;
@@ -102,7 +102,7 @@ public class InterceptorRegistry {
 //    SimpleAroundInterceptor getInterceptor0(int key) {
 //        StaticAfterInterceptor interceptor = index[key];
 //        if (interceptor == null) {
-//            // 로직이 잘못되었을 경우 에러가 발생하지 않도록 더미를 리턴.
+//            // return DUMMY upon wrong logic
 //            return DUMMY;
 //        }
 //        return interceptor;

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/interceptor/ParameterExtractor.java

@@ -17,7 +17,7 @@
 package com.navercorp.pinpoint.bootstrap.interceptor;
 
 /**
- * 객체 생성을 줄이기 위해서 객체를 리턴하지 않고 c 스타일 api로 디자인함.
+ * C-style API (doesn't return an object) in order to reduce the number of object instantiating 
  * @author emeroad
  */
 public interface ParameterExtractor {

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/interceptor/SpanSimpleAroundInterceptor.java

@@ -49,7 +49,7 @@ public abstract class SpanSimpleAroundInterceptor implements SimpleAroundInterce
             if (trace == null) {
                 return;
             }
-            // TODO STATDISABLE 일단 통계 저장기능을 disable하기 위해 아래 로직을 추가함.
+            // TODO STATDISABLE this logic was added to disable statstics tracing
             if (!trace.canSampled()) {
                 return;
             }
@@ -77,7 +77,7 @@ public abstract class SpanSimpleAroundInterceptor implements SimpleAroundInterce
             return;
         }
         traceContext.detachTraceObject();
-        // TODO STATDISABLE 일단 통계 저장기능을 disable하기 위해 아래 로직을 추가함.
+        // TODO STATDISABLE this logic was added to disable statstics tracing
         if (!trace.canSampled()) {
             return;
         }

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/logging/PLoggerFactory.java

@@ -35,8 +35,8 @@ public final class PLoggerFactory {
     }
 
     public static void unregister(PLoggerBinder loggerBinder) {
-        // 등록한 놈만  제거 가능하도록 제한
-        // testcase 작성시 가능한 logger를 등록했다가 삭제하는 로직은 beforeClass, afterClass에 넣어야 한다.
+        // Limited to remove only the ones already registered
+        // when writing a test case, logger register/unregister logic must be located in beforeClass and afterClass
         if (loggerBinder == PLoggerFactory.loggerBinder) {
             PLoggerFactory.loggerBinder = null;
         }
@@ -44,7 +44,7 @@ public final class PLoggerFactory {
 
     public static PLogger getLogger(String name) {
         if (loggerBinder == null) {
-            // 바인딩 되지 않은 상태에서 getLogger를 호출시 null ex가 발생하므로 dummy logger를 리턴하도록 함.
+            // this prevents null exception: need to return Dummy until a Binder is assigned
             return DummyPLogger.INSTANCE;
         }
         return loggerBinder.getLogger(name);

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/pair/NameIntValuePair.java

@@ -17,8 +17,8 @@
 package com.navercorp.pinpoint.bootstrap.pair;
 
 /**
- * classLoading구조에서 interceptor가 parent에 위치하면서 멀티 value access 데이터 전달이 필요할 경우의 공통 자료구조로 사용한다.
- * value가 int type일때 사용
+ * need to use common data structure when classLoading intercepter is in parent and, at the same time, multiple "value access" data are needed.
+ * Use this when value is "int" type.
  * @author emeroad
  */
 public class NameIntValuePair<T> {

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/pair/NameValuePair.java

@@ -17,7 +17,7 @@
 package com.navercorp.pinpoint.bootstrap.pair;
 
 /**
- * classLoading구조에서 interceptor가 parent에 위치하면서 멀티 value access 데이터 전달이 필요할 경우의 공통 자료구조로 사용한다.
+ * need to use common data structure when classLoading intercepter is in parent and, at the same time, multiple "value access" data are needed.
  * @author emeroad
  */
 public class NameValuePair<T, V> {

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/plugin/BytecodeUtils.java

@@ -39,10 +39,10 @@ public final class BytecodeUtils {
             return method;
         } catch (NoSuchMethodException e) {
             // link error
-            throw new RuntimeException("defineClass not found. Caused:" + e.getMessage(), e);
+            throw new RuntimeException("defineClass not found. Error:" + e.getMessage(), e);
         } catch (SecurityException e) {
             // link error
-            throw new RuntimeException("defineClass error. Caused:" + e.getMessage(), e);
+            throw new RuntimeException("defineClass error. Error:" + e.getMessage(), e);
         }
     }
 

bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/sampler/SamplingFlagUtils.java

@@ -21,8 +21,7 @@ package com.navercorp.pinpoint.bootstrap.sampler;
  */
 public final class SamplingFlagUtils {
 
-    // 향후 다른 샘플링 스펙이 추가될수 있으므로
-    // 일부러 1개 byte를 소비하여 sampling마크 한다.
+    // 1 byte dummy mark for further expansion of sampling specs
     public static final String SAMPLING_RATE_PREFIX = "s";
 
 
@@ -36,8 +35,8 @@ public final class SamplingFlagUtils {
         if (samplingFlag == null) {
             return true;
         }
-        // 정확하게 하지 말란 flag가 세팅되었을 경우만 샘플링을 하지 않는다.
-        // prefix를 보고 뭔가 더 정확하게 동작되어야 필요성이 있음.
+        // we turn off sampling only when a specific flag was given
+        // XXX needs better detection mechanism through prefix parsing
         if (samplingFlag.startsWith(SAMPLING_RATE_PREFIX)) {
             return !SAMPLING_RATE_FALSE.equals(samplingFlag);
         }

web/src/main/java/com/navercorp/pinpoint/web/alarm/AlarmPartitioner.java

@@ -36,40 +36,40 @@ public class AlarmPartitioner implements Partitioner {
     private final Logger logger = LoggerFactory.getLogger(this.getClass());
     public static final int APP_COUNT = 5;
     public static final String PARTITION_NUMBER = "partition_number";
-    
+
     @Autowired
     private ApplicationIndexDao applicationIndexDao;
-    
+
     public AlarmPartitioner() {
     }
-    
+
     protected AlarmPartitioner(ApplicationIndexDao applicationIndexDao) {
         this.applicationIndexDao = applicationIndexDao;
     }
-    
+
     @Override
     public Map<String, ExecutionContext> partition(int gridSize) {
         int partitionCount = calculateGroupCount();
         Map<String, ExecutionContext> mapContext = new HashMap<String, ExecutionContext>();
-        
+
         for (int i = 1; i <= partitionCount; i++) {
             ExecutionContext executionContext = new ExecutionContext();
             executionContext.put(PARTITION_NUMBER, i);
             mapContext.put(PARTITION_NUMBER + "_" + i, executionContext);
         }
-        
+
         return mapContext;
-    }    
-    
+    }
+
     public int calculateGroupCount() {
         List<Application> applicationList = applicationIndexDao.selectAllApplicationNames();
         int partitionCount = applicationList.size() / APP_COUNT;
-        
+
         if (applicationList.size() % APP_COUNT != 0) {
             partitionCount++;
         }
-        
-        logger.info("application count is {}. patition count is {}", applicationList.size(), partitionCount);
+
+        logger.info("application count is {}. partition count is {}", applicationList.size(), partitionCount);
         return partitionCount;
     }
 }

web/src/main/java/com/navercorp/pinpoint/web/alarm/DataCollectorFactory.java

@@ -34,23 +34,23 @@ import com.navercorp.pinpoint.web.vo.Application;
  */
 @Component
 public class DataCollectorFactory {
-    
+
     public final static long SLOT_INTERVAL_FIVE_MIN = 300000;
-    
+
     public final static long SLOT_INTERVAL_THREE_MIN = 180000;
 
     @Autowired
     private HbaseMapResponseTimeDao hbaseMapResponseTimeDao;
-    
+
     @Autowired
     private HbaseAgentStatDao hbaseAgentStatDao;
-    
+
     @Autowired
     private HbaseApplicationIndexDao hbaseApplicationIndexDao;
-    
+
     @Autowired
     private HbaseMapStatisticsCallerDao mapStatisticsCallerDao;
-    
+
     public DataCollector createDataCollector(CheckerCategory checker, Application application, long timeSlotEndTime) {
         switch (checker.getDataCollectorCategory()) {
         case RESPONSE_TIME:
@@ -60,11 +60,11 @@ public class DataCollectorFactory {
         case CALLER_STAT:
             return new MapStatisticsCallerDataCollector(DataCollectorCategory.CALLER_STAT, application, mapStatisticsCallerDao, timeSlotEndTime, SLOT_INTERVAL_FIVE_MIN);
         }
-        
-        throw new IllegalArgumentException("not create DataCollector : " + checker.getName());
-        
+
+        throw new IllegalArgumentException("unable to create DataCollector : " + checker.getName());
+
     }
-    
+
     public enum DataCollectorCategory {
         RESPONSE_TIME,
         AGENT_STAT,

web/src/main/java/com/navercorp/pinpoint/web/alarm/collector/AgentStatDataCollector.java

@@ -38,19 +38,19 @@ public class AgentStatDataCollector extends DataCollector {
     private final ApplicationIndexDao applicationIndexDao;
     private final long timeSlotEndTime;
     private final long slotInterval;
-    private final AtomicBoolean init = new AtomicBoolean(false); // need to consider the concurrency situation when checkers start simultaneously.
-   
+    private final AtomicBoolean init = new AtomicBoolean(false); // need to consider a race condition when checkers start simultaneously.
+
     private final Map<String, Long> agentHeapUsageRate = new HashMap<String, Long>();
     private final Map<String, Long> agentGcCount = new HashMap<String, Long>();
     private final Map<String, Long> agentJvmCpuUsageRate = new HashMap<String, Long>();
-    
+
     public AgentStatDataCollector(DataCollectorCategory category, Application application, AgentStatDao agentStatDao, ApplicationIndexDao applicationIndexDao, long timeSlotEndTime, long slotInterval) {
         super(category);
         this.application = application;
         this.agentStatDao = agentStatDao;
         this.applicationIndexDao = applicationIndexDao;
         this.timeSlotEndTime = timeSlotEndTime;
-        this.slotInterval = slotInterval; 
+        this.slotInterval = slotInterval;
     }
 
     @Override
@@ -58,40 +58,40 @@ public class AgentStatDataCollector extends DataCollector {
         if (init.get()) {
             return;
         }
-        
+
         Range range = Range.createUncheckedRange(timeSlotEndTime - slotInterval, timeSlotEndTime);
         List<String> agentIds = applicationIndexDao.selectAgentIds(application.getName());
-        
+
         for(String agentId : agentIds) {
             List<AgentStat> scanAgentStatList = agentStatDao.scanAgentStatList(agentId, range);
             int listSize = scanAgentStatList.size();
             long totalHeapSize = 0;
             long usedHeapSize = 0;
             long jvmCpuUsaged = 0;
-            
+
             for (AgentStat agentStat : scanAgentStatList) {
                 totalHeapSize += agentStat.getMemoryGc().getJvmMemoryHeapMax();
                 usedHeapSize += agentStat.getMemoryGc().getJvmMemoryHeapUsed();
-                
+
                 jvmCpuUsaged += agentStat.getCpuLoad().getJvmCpuLoad() * 100;
             }
-            
+
             if(listSize > 0) {
                 long percent = calculatePercent(usedHeapSize, totalHeapSize);
                 agentHeapUsageRate.put(agentId, percent);
-                
+
                 percent = calculatePercent(jvmCpuUsaged, 100*scanAgentStatList.size());
                 agentJvmCpuUsageRate.put(agentId, percent);
-                
+
                 long accruedLastGCcount = scanAgentStatList.get(0).getMemoryGc().getJvmGcOldCount();
                 long accruedFirstGCcount= scanAgentStatList.get(listSize - 1).getMemoryGc().getJvmGcOldCount();
-                agentGcCount.put(agentId, accruedLastGCcount - accruedFirstGCcount);    
+                agentGcCount.put(agentId, accruedLastGCcount - accruedFirstGCcount);
             }
-            
+
         }
 
         init.set(true);
-        
+
     }
 
     private long calculatePercent(long used, long total) {
@@ -113,5 +113,5 @@ public class AgentStatDataCollector extends DataCollector {
     public Map<String, Long> getJvmCpuUsageRate() {
         return agentJvmCpuUsageRate;
     }
-    
+
 }

web/src/main/java/com/navercorp/pinpoint/web/alarm/collector/MapStatisticsCallerDataCollector.java

@@ -36,18 +36,18 @@ import com.navercorp.pinpoint.web.vo.Range;
 public class MapStatisticsCallerDataCollector extends DataCollector {
 
     private Application application;
-    private MapStatisticsCallerDao mapStatisticsCallerDao; 
+    private MapStatisticsCallerDao mapStatisticsCallerDao;
     private long timeSlotEndTime;
     private long slotInterval;
     private Map<String, LinkCallData> calleStatMap = new HashMap<String, LinkCallData>();
-    private final AtomicBoolean init =new AtomicBoolean(false); // need to consider the concurrency situation when checkers start simultaneously.
-    
+    private final AtomicBoolean init =new AtomicBoolean(false); // need to consider a trace condition when checkers start simultaneously.
+
     public MapStatisticsCallerDataCollector(DataCollectorCategory category, Application application, MapStatisticsCallerDao mapStatisticsCallerDao, long timeSlotEndTime, long slotInterval) {
         super(category);
         this.application = application;
         this.mapStatisticsCallerDao = mapStatisticsCallerDao;
         this.timeSlotEndTime = timeSlotEndTime;
-        this.slotInterval = slotInterval; 
+        this.slotInterval = slotInterval;
     }
 
     @Override
@@ -55,24 +55,24 @@ public class MapStatisticsCallerDataCollector extends DataCollector {
         if (init.get()) {
             return;
         }
-        
+
         LinkDataMap callerDataMap = mapStatisticsCallerDao.selectCaller(application, new Range(timeSlotEndTime - slotInterval, timeSlotEndTime));
 
         for (LinkData linkData : callerDataMap.getLinkDataList()) {
             LinkCallDataMap linkCallDataMap = linkData.getLinkCallDataMap();
-       
+
             for (LinkCallData linkCallData : linkCallDataMap.getLinkDataList()) {
                 calleStatMap.put(linkCallData.getTarget(), linkCallData);
             }
         }
-        
+
         init.set(true);
     }
 
     public long getCount(String calleName, DataCategory dataCategory) {
         LinkCallData linkCallData = calleStatMap.get(calleName);
         long count = 0;
-        
+
         if (linkCallData != null) {
             switch (dataCategory) {
             case SLOW_COUNT:
@@ -94,18 +94,18 @@ public class MapStatisticsCallerDataCollector extends DataCollector {
             default :
                 throw new IllegalArgumentException("Can't count for " + dataCategory.toString());
             }
-            
+
             return count;
         }
-        
+
         return 0;
     }
-    
+
     public long getCountRate(String calleName, DataCategory dataCategory) {
         LinkCallData linkCallData = calleStatMap.get(calleName);
         long count = 0;
         long totalCount = 0;
-        
+
         if (linkCallData != null) {
             switch (dataCategory) {
             case SLOW_RATE:
@@ -124,10 +124,10 @@ public class MapStatisticsCallerDataCollector extends DataCollector {
             default :
                 throw new IllegalArgumentException("Can't calculate rate for " + dataCategory.toString());
             }
-            
+
             return calculatePercent(count, totalCount);
         }
-        
+
         return 0;
     }
 

web/src/main/java/com/navercorp/pinpoint/web/alarm/collector/ResponseTimeDataCollector.java

@@ -36,20 +36,20 @@ public class ResponseTimeDataCollector extends DataCollector {
     private final MapResponseDao responseDao;
     private final long timeSlotEndTime;
     private final long slotInterval;
-    private final AtomicBoolean init =new AtomicBoolean(false); // need to consider the concurrency situation when checkers start simultaneously.
-    
+    private final AtomicBoolean init =new AtomicBoolean(false); // need to consider a race condition when checkers start simultaneously.
+
     private long slowCount = 0;
     private long errorCount = 0;
     private long totalCount = 0;
     private long slowRate = 0;
     private long errorRate = 0;
-    
+
     public ResponseTimeDataCollector(DataCollectorCategory category, Application application, MapResponseDao responseDAO, long timeSlotEndTime, long slotInterval) {
         super(category);
         this.application = application;
         this.responseDao = responseDAO;
         this.timeSlotEndTime = timeSlotEndTime;
-        this.slotInterval = slotInterval; 
+        this.slotInterval = slotInterval;
     }
 
     @Override
@@ -57,14 +57,14 @@ public class ResponseTimeDataCollector extends DataCollector {
         if (init.get()) {
             return;
         }
-        
+
         Range range = Range.createUncheckedRange(timeSlotEndTime - slotInterval, timeSlotEndTime);
         List<ResponseTime> responseTimes = responseDao.selectResponseTime(application, range);
-        
+
         for (ResponseTime responseTime : responseTimes) {
             sum(responseTime.getAgentResponseHistogramList());
         }
-        
+
         setSlowRate();
         setErrorRate();
 
@@ -74,11 +74,11 @@ public class ResponseTimeDataCollector extends DataCollector {
     private void setSlowRate() {
         slowRate = calculatePercent(slowCount);
     }
-    
+
     private void setErrorRate() {
         errorRate = calculatePercent(errorCount);
     }
-    
+
     private long calculatePercent(long value) {
         if (totalCount == 0 || value == 0) {
             return 0;
@@ -95,15 +95,15 @@ public class ResponseTimeDataCollector extends DataCollector {
             totalCount += timeHistogram.getTotalCount();
         }
     }
-    
+
     public long getSlowCount() {
         return slowCount;
     }
-    
+
     public long getErrorCount() {
         return errorCount;
     }
-    
+
     public long getTotalCount() {
         return totalCount;
     }

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/ApplicationMapBuilder.java

@@ -39,9 +39,9 @@ public class ApplicationMapBuilder {
     private final Logger logger = LoggerFactory.getLogger(this.getClass());
 
     private final Range range;
-    
+
     private MatcherGroup matcherGroup;
-    
+
     public ApplicationMapBuilder(Range range, MatcherGroup matcherGroup) {
         if (range == null) {
             throw new NullPointerException("range must not be null");
@@ -115,8 +115,8 @@ public class ApplicationMapBuilder {
 
         for (LinkData linkData : linkDataMap.getLinkDataList()) {
             final Application fromApplication = linkData.getFromApplication();
-            // FROM -> TO에서 FROM이 CLIENT가 아니면 FROM은 node
-            // rpc가 나올수가 없음. 이미 unknown으로 치환을 하기 때문에. 만약 rpc가 나온다면 이상한 케이스임
+            // FROM is either a CLIENT or a node
+            // cannot be RPC. Already converted to unknown.
             if (!fromApplication.getServiceType().isRpcClient()) {
                 final boolean success = addNode(nodeList, fromApplication);
                 if (success) {

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/CreateType.java

@@ -17,7 +17,8 @@
 package com.navercorp.pinpoint.web.applicationmap;
 
 /**
- * 호출한 정보에 의해서 생성된거면 Source, 호출당한 정보에 의해서 생성되면 Target
+ * Source if created with caller information
+ * Target if created with callee information
  * @author emeroad
  */
 public enum CreateType {

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/Link.java

@@ -37,8 +37,8 @@ import java.util.List;
 import java.util.Set;
 
 /**
- * application map에서 application간의 관계를 담은 클래스
- * 
+ * A class that describes relationship between apps in application map
+ *
  * @author netspider
  * @author emeroad
  */
@@ -48,8 +48,8 @@ public class Link {
 
     public static final String LINK_DELIMITER = "~";
 
-    // 링크를 생성한 데이터의 주체가 누구인가를 나타냄
-    // source에 의해서 먼저 생성된것인지, target에 의해서 수동적으로 생성된것인지 나타낸다.
+    // specified who created a link.
+    // indicates whether created by a source or manually created by a target
     private final CreateType createType;
     private final Node fromNode;
     private final Node toNode;
@@ -92,8 +92,8 @@ public class Link {
     }
 
     public Application getFilterApplication() {
-        // User 링크일 경우 from을 보면 안되고 was를 봐야 한다.
-        // User는 가상의 링크이기 때문에, User로 필터링을 칠수 없음.
+        // User link: need to look at WAS, not from
+        // Since User is a virtual link, we cannot filter by User
         if (fromNode.getServiceType() == ServiceType.USER) {
             return toNode.getApplication();
         }
@@ -147,8 +147,8 @@ public class Link {
 	}
 
     private Histogram createHistogram0() {
-        // 내가 호출하는 대상의 serviceType을 가져와야 한다.
-        // tomcat -> arcus를 호출한다고 하였을 경우 arcus의 타입을 가져와야함.
+        // need serviceType of target (callee)
+        // ie. Tomcat -> Arcus: we need arcus type
         final LinkCallDataMap findMap = getLinkCallDataMap();
         AgentHistogramList targetList = findMap.getTargetList();
         return targetList.mergeHistogram(toNode.getServiceType());
@@ -174,8 +174,8 @@ public class Link {
     }
 
     public Histogram getTargetHistogram() {
-        // 내가 호출하는 대상의 serviceType을 가져와야 한다.
-        // tomcat -> arcus를 호출한다고 하였을 경우 arcus의 타입을 가져와야함.
+        // need serviceType of target (callee)
+        // ie. Tomcat -> Arcus: we need Arcus type
         AgentHistogramList targetList = targetLinkCallDataMap.getTargetList();
         return targetList.mergeHistogram(toNode.getServiceType());
 
@@ -201,20 +201,20 @@ public class Link {
     }
 
     private ApplicationTimeHistogram getSourceApplicationTimeSeriesHistogramData() {
-        // form인것 같지만 link의 시간은 rpc를 기준으로 삼아야 하기 때문에. to를 기준으로 삼아야 한다.
+        // we need Target (to)'s time since time in link is RPC-based
         ApplicationTimeHistogramBuilder builder = new ApplicationTimeHistogramBuilder(toNode.getApplication(), range);
         return builder.build(sourceLinkCallDataMap.getLinkDataList());
     }
 
     public ApplicationTimeHistogram getTargetApplicationTimeSeriesHistogramData() {
-        // form인것 같지만 link의 시간은 rpc를 기준으로 삼아야 하기 때문에. to를 기준으로 삼아야 한다.
+        // we need Target (to)'s time since time in link is RPC-based
         ApplicationTimeHistogramBuilder builder = new ApplicationTimeHistogramBuilder(toNode.getApplication(), range);
         return builder.build(targetLinkCallDataMap.getLinkDataList());
     }
 
     public AgentResponseTimeViewModelList getSourceAgentTimeSeriesHistogram() {
 
-        // form인것 같지만 link의 시간은 rpc를 기준으로 삼아야 하기 때문에. to를 기준으로 삼아야 한다.
+        // we need Target (to)'s time since time in link is RPC-based
         AgentTimeHistogramBuilder builder = new AgentTimeHistogramBuilder(toNode.getApplication(), range);
         AgentTimeHistogram applicationTimeSeriesHistogram = builder.buildSource(sourceLinkCallDataMap);
         AgentResponseTimeViewModelList agentResponseTimeViewModelList = new AgentResponseTimeViewModelList(applicationTimeSeriesHistogram.createViewModel());

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/LinkList.java

@@ -43,7 +43,7 @@ public class LinkList {
     }
 
     /**
-     * toApplication을 가리키는(호출당하는) 모든 link를 찾음.
+     * find all callers of toApplication
      * @param toApplication
      * @return
      */
@@ -55,7 +55,7 @@ public class LinkList {
         List<Link> findList = new ArrayList<Link>();
         for (Link link : linkMap.values()) {
             Node toNode = link.getTo();
-            // destnation이 자신을 가리키는 모든 Link를 찾음.
+            // find all the callers of toApplication/destination
             if (toNode.getApplication().equals(toApplication)) {
                 findList.add(link);
             }
@@ -64,7 +64,7 @@ public class LinkList {
     }
 
     /**
-     * fromApplication 에서 나가는(호출하는) link를 모두 찾음.
+     * find all callees of fromApplication
      * @param fromApplication
      * @return
      */

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/LinkStateResolver.java

@@ -29,7 +29,8 @@ public class LinkStateResolver {
         if (link == null) {
             throw new NullPointerException("link must not be null");
         }
-        // Histogram이 중복으로 생성되고 있어 그냥 인자로 받음 수정 요망.
+        // since Histogram dup gets created, we simply accepts as a parameter
+        // XXX need to fix this 
         final long error = getErrorRate(link.getHistogram());
         if (error * 100 > 10) {
             return BAD;

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/Node.java

@@ -30,8 +30,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * node map에서 application을 나타낸다.
- * 
+ * class for application in node map
+ *
  * @author netspider
  * @author emeroad
  */
@@ -47,7 +47,8 @@ public class Node {
     private ServerInstanceList serverInstanceList;
 
     private NodeHistogram nodeHistogram;
-    // 임시로 생성.
+
+    // temporary
     private static final ObjectMapper MAPPER = new ObjectMapper();
 
 

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/ServerBuilder.java

@@ -79,7 +79,7 @@ public class ServerBuilder {
     }
 
     /**
-     * 어플리케이션에 속한 물리서버와 서버 인스턴스 정보를 채운다.
+     * filled with application information of physical server and service instance
      *
      * @param hostHistogram
      */
@@ -110,11 +110,11 @@ public class ServerBuilder {
 
     public ServerInstanceList build() {
         if (!agentSet.isEmpty()) {
-            // agent이름이 존재할 경우. 실제 리얼 서버가 존재할 경우
+            // only when agent name exists or real server exists
             this.logger.debug("buildPhysicalServer:{}", agentSet);
             return buildPhysicalServer(agentSet);
         } else {
-            // 논리 이름으로 구성.
+            // otherwise, logical name
             this.logger.debug("buildLogicalServer");
             return buildLogicalServer(agentHistogramList);
         }

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/ServerInstance.java

@@ -24,7 +24,7 @@ import com.navercorp.pinpoint.web.applicationmap.link.MatcherGroup;
 import com.navercorp.pinpoint.web.applicationmap.link.ServerMatcher;
 
 /**
- * 
+ *
  * @author netspider
  * @author emeroad
  */
@@ -40,7 +40,8 @@ public class ServerInstance {
 	private final AgentInfoBo agentInfo;
 
 
-    // 모양세는 어디선가 inject받던지 하는게 좋은데. 일단 그냥 한다. 로직에서 new하는 부분이라. 이걸 inject받을려니 힘듬.
+    // it is better for something else to inject this.
+    // it's difficult to do that since it is new'ed within logic
     private static final MatcherGroup MATCHER_GROUP = new MatcherGroup();
 
     private ServerMatcher match;
@@ -56,7 +57,7 @@ public class ServerInstance {
         this.serverType = ServerType.Physical;
         this.match = MATCHER_GROUP.match(hostName);
 	}
-	
+
 	public ServerInstance(String hostName, String physicalName, ServiceType serviceType) {
         if (hostName == null) {
             throw new NullPointerException("hostName must not be null");

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/ServerInstanceList.java

@@ -41,12 +41,12 @@ public class ServerInstanceList {
 	private final Logger logger = LoggerFactory.getLogger(this.getClass());
 
 	private final Map<String, List<ServerInstance>> serverInstanceList = new TreeMap<String, List<ServerInstance>>();
-	   
+
     private MatcherGroup matcherGroup = new MatcherGroup();
-	
+
 	public ServerInstanceList() {
 	}
-	   
+
     public ServerInstanceList(MatcherGroup matcherGroup) {
         if (matcherGroup != null) {
             this.matcherGroup.addMatcherGroup(matcherGroup);
@@ -54,7 +54,7 @@ public class ServerInstanceList {
     }
 
 	public Map<String, List<ServerInstance>> getServerInstanceList() {
-		// list의 소트가 안되 있는 문제가 있음.
+		// XXX list sorting problem exist
 		return serverInstanceList;
 	}
 
@@ -89,14 +89,14 @@ public class ServerInstanceList {
 		List<ServerInstance> find = getServerInstanceList(serverInstance.getHostName());
 		addServerInstance(find, serverInstance);
 	}
-	
+
     public Map<String, String> getLink(String serverName) {
         ServerMatcher serverMatcher = matcherGroup.match(serverName);
-        
+
         Map<String, String> linkInfo = new HashMap<String, String>();
         linkInfo.put("linkName", serverMatcher.getLinkName());
         linkInfo.put("linkURL", serverMatcher.getLink(serverName));
-        
+
         return linkInfo;
     }
 

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/histogram/AgentTimeHistogram.java

@@ -34,8 +34,8 @@ import org.slf4j.LoggerFactory;
 import java.util.*;
 
 /**
- * 리팩토링하면서 AgentHistogramList에 기능이 거의 위임되었음.
- * viewCreate정도로 기능이 한정되서 추후 삭제하거나. 이름을 변경해야 될듯하다.
+ * most of the features have been delegated to AgentHistorgramList upon refactoring
+ * TODO: limited to viewCreate. need to be renamed or removed
  * @author emeroad
  */
 public class AgentTimeHistogram {

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/histogram/AgentTimeHistogramBuilder.java

@@ -87,9 +87,9 @@ public class AgentTimeHistogramBuilder {
             return new AgentHistogramList();
         }
 
-        // window 공간생성. AgentHistogramList 사용이전에는 그냥 생짜 자료구조를 사용함.
-        // list로 할수도 있으나, filter일 경우 range를 초과하는 경우가 발생할 가능성이 있어 map으로 생성한다.
-        // 좀더 나은 방인이 있으면 변경하는게 좋을듯.
+        // window space. before AgentHistogramList, we used a raw data structure.
+        // could've been a list, but a map is more suitable since range overflow occurs in case of filter.
+        // TODO: find better structure
         final AgentHistogramList resultAgentHistogramList = new AgentHistogramList();
         for (AgentHistogram agentHistogram : agentHistogramList.getAgentHistogramList()) {
             List<TimeHistogram> timeHistogramList = new ArrayList<TimeHistogram>();

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/histogram/ApplicationTimeHistogramBuilder.java

@@ -66,7 +66,7 @@ public class ApplicationTimeHistogramBuilder {
                 timeHistogram = new TimeHistogram(application.getServiceType(), timeStamp);
                 applicationLevelHistogram.put(timeStamp, timeHistogram);
             }
-            // 개별 agent 레벨 데이터를 합친다.
+            // add each agent's level data
             Histogram applicationResponseHistogram = responseTime.getApplicationResponseHistogram();
             timeHistogram.add(applicationResponseHistogram);
         }
@@ -109,7 +109,7 @@ public class ApplicationTimeHistogramBuilder {
     }
 
     private List<TimeHistogram> interpolation(Collection<TimeHistogram> histogramList) {
-        // span에 대한 개별 조회시 window time만 가지고 보간하는것에 한계가 있을수 있음.
+        // upon individual span query, "window time" alone may not be enough
         //
         Map<Long, TimeHistogram> resultMap = new HashMap<Long, TimeHistogram>();
         for (Long time : window) {

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/histogram/Histogram.java

@@ -31,7 +31,7 @@ import com.fasterxml.jackson.databind.annotation.JsonSerialize;
  */
 @JsonSerialize(using=HistogramSerializer.class)
 public class Histogram {
-	
+
 	private final HistogramSchema schema;
 
     private long fastCount;
@@ -67,7 +67,7 @@ public class Histogram {
         this(ServiceType.findServiceType(serviceType));
     }
 
-	// TODO slot번호를 이 클래스에서 추출해야 할 것 같긴 함.
+	// TODO one may extract slot number from this class
 	public void addCallCount(final short slotTime, final long count) {
         final HistogramSchema schema = this.schema;
 		if (slotTime == schema.getVerySlowSlot().getSlotTime()) { // 0 is slow slotTime
@@ -78,7 +78,7 @@ public class Histogram {
 			this.errorCount += count;
 			return;
 		}
-        // TODO slotTime 은 <= 아니고 ==으로 수정되어야함.
+				// TODO if clause condition should be "==", not "<="
         if (slotTime <= schema.getFastSlot().getSlotTime()) {
             this.fastCount += count;
             return;

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/histogram/NodeHistogram.java

@@ -26,11 +26,11 @@ import org.slf4j.LoggerFactory;
 import java.util.*;
 
 /**
+ * this class is a collection of
  * applicationHistogram
  * agentHistogram
  * applicationTimeHistogram
  * agentTimeHistogram
- * 의 집합
  * @author emeroad
  */
 public class NodeHistogram {
@@ -44,7 +44,7 @@ public class NodeHistogram {
     // ApplicationLevelHistogram
     private Histogram applicationHistogram;
 
-    // key는 agentId이다.
+    // key is agentId
     private Map<String, Histogram> agentHistogramMap;
 
     private ApplicationTimeHistogram applicationTimeHistogram;

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/rawdata/AgentHistogram.java

@@ -28,14 +28,14 @@ import java.util.HashMap;
 import java.util.Map;
 
 /**
- * 
+ *
  * @author netspider
  * @author emeroad
  */
 
 public class AgentHistogram {
 	/**
-	 * UI에서 호스트를 구분하기 위한 목적으로 hostname, agentid, endpoint등 구분할 수 있는 아무거나 넣으면 됨.
+	 * to uniquely identify a host from UI, we can use things like hostname, agentId, endpoint, etc
 	 */
 	private final Application agentId;
 
@@ -115,7 +115,7 @@ public class AgentHistogram {
         final StringBuilder sb = new StringBuilder("AgentHistogram{");
         sb.append("agent='").append(agentId.getName()).append('\'');
         sb.append(", serviceType=").append(agentId.getServiceType());
-        // 자료 구조가 변경되어 잠시 땜빵.
+				// temporarily hard-coded due to a change in the data structure
         sb.append(", ").append(timeHistogramMap);
         sb.append('}');
         return sb.toString();

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/rawdata/AgentHistogramList.java

@@ -33,7 +33,8 @@ import java.util.*;
 public class AgentHistogramList {
 
     private final Logger logger = LoggerFactory.getLogger(this.getClass());
-    // agent별 Time 시리즈 데이터를 가지고 있음.
+
+    // stores times series data per agent
     private final Map<Application, AgentHistogram> agentHistogramMap = new HashMap<Application, AgentHistogram>();
 
     public AgentHistogramList() {

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/rawdata/LinkCallData.java

@@ -24,7 +24,7 @@ import com.navercorp.pinpoint.web.vo.LinkKey;
 import java.util.*;
 
 /**
- * 호출관계의 양방향 데이터를 표현
+ * representation of caller/callee relationship 
  * @author emeroad
  */
 public class LinkCallData {

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/rawdata/LinkCallDataMap.java

@@ -106,8 +106,9 @@ public class LinkCallDataMap {
         for (Map.Entry<LinkKey, LinkCallData> linkKeyRawCallDataEntry : linkDataMap.entrySet()) {
             final LinkKey key = linkKeyRawCallDataEntry.getKey();
             final LinkCallData linkCallData = linkKeyRawCallDataEntry.getValue();
-            // to의 ServiceType이 들어가야 한다.
-            // 여기서 source란 source의 입장에서 target 호출시의 데이터를 의미하는 것이기 때문에. ServiceType자체는 To의 ServiceType이 들어가야한다.
+            // need target (to) ServiceType
+            // the definition of source is data from the source when the source sends a request to a target.
+            // Thus ServiceType is the target's ServiceType
             sourceList.addAgentHistogram(key.getFromApplication(), key.getToServiceType(), linkCallData.getTimeHistogram());
         }
         return sourceList;

web/src/main/java/com/navercorp/pinpoint/web/applicationmap/rawdata/LinkData.java

@@ -23,8 +23,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * DB에서 조회한 application호출 관계 정보.
- * 
+ * application caller/callee relationship stored in DB
+ *
  * @author netspider
  * @author emeroad
  */
@@ -50,7 +50,7 @@ public class LinkData {
         this.linkCallDataMap = new LinkCallDataMap();
 	}
 
-    // 이건 일부러 복사 생성자로 구현안함.
+    // deliberaly didn't implement copy constructor
     public LinkData(Application fromApplication, Application toApplication, LinkCallDataMap linkCallDataMap) {
         if (fromApplication == null) {
             throw new NullPointerException("fromApplication must not be null");
@@ -65,9 +65,9 @@ public class LinkData {
     }
 
     /**
-	 * 
+	 *
 	 * @param hostname
-	 *            host이름 또는 endpoint
+	 *            host name or endpoint
 	 * @param slot
 	 * @param count
 	 */

web/src/main/java/com/navercorp/pinpoint/web/calltree/span/SpanAligner2.java

@@ -25,18 +25,18 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ *
  * @author netspider
  * @author emeroad
  */
 public class SpanAligner2 {
     private final Logger logger = LoggerFactory.getLogger(this.getClass());
 
-    // 매치가 안됨.
+    // not matched
     public static final int FAIL_MATCH = 0;
-    // transaction이 완벽하게 끝남.
+    // transaction completed succesfully
     public static final int BEST_MATCH = 1;
-    // transaction이 진행중이거나. 일부 분실된 데이터가 있음.
+    // transaction in-flight or missing data
     public static final int START_TIME_MATCH = 2;
 
 
@@ -61,33 +61,33 @@ public class SpanAligner2 {
                 root.add(span);
             }
         }
-        // 최상 조건의 best매치. 완벽 조건의 매치.
+        // perfect match condition
         final int rootSpanBoSize = root.size();
         if (rootSpanBoSize == 1) {
             final SpanBo spanBo = root.get(0);
             logger.debug("root span found. best match:{}", spanBo);
             matchType = BEST_MATCH;
-            // 틈세가 추가로 있음. root는 있으나 조회한 span이 없을 경우 추가처리가 있어야함.
+            // XXX in case where root exist but no span queried. additional logic needed
             return spanBo.getSpanId();
         }
-        // 버그 rootspan이 2개 이상인 경우는 로직 버그이다. 아무거나 잡아서 데이터를 뿌려줘야 되나?
+        // XXX: a bug in the logic if rootspan is more than 2. should we display randomly?
         if (rootSpanBoSize > 1) {
             logger.warn("parentSpanId(-1) collision. size:{} root span:{} allSpan:{}", rootSpanBoSize, root, spanList);
             throw new IllegalStateException("parentSpanId(-1) collision. size:" + rootSpanBoSize);
         }
 
-        // root 분실. 혹은 아직 도착하지 않아 root가 완성 되지 않음. 즉 진행중인 process일 수 있음.
-        // 차선책으로 자신이 조회한 span의 시작 시간을 기준으로 span을 조회한다.
-        // span에서 데이터를 추출하는 것이기 때문에, 왠간하면 데이터는 존재함. hbase insert시 data insert를 실패할 경우 없을수 있음.
+        // missing root or incomplete root (not arrived yet): meaning on-going process
+        // next best thing is to lookup span based on the beginning of time of span it looked up
+        // most likely data exist since the data gets extracted from span. non-existent data possible due to hbase insertion failure
         final List<SpanBo> collectorAcceptTimeMatcher = new ArrayList<SpanBo>();
         for(SpanBo span : spanList) {
-            // collectorTime이 힌트로 들어온다.
+            // collectorTime is a hint
             if (span.getCollectorAcceptTime() == collectorAcceptTime) {
                 collectorAcceptTimeMatcher.add(span);
             }
         }
-        // startTime 기반 match. 아래 추가 정보가 제공 되면 더 정확하게 매치가 가능하다.
-        // 이중에서 어느 정보를 얻으면 가장 쉽고 정확하게 매치가 가능한가? agentId가 제일 무난하지 않나 함.
+        // a match based on startTime. a further accurate match when additional informations (below) are given
+        // which one of these leads to a best match?  possibly agentId.
         // "applicationName" : "/httpclient4/post.pinpoint",
         // "transactionId" : "emeroad-pc^1382955966412^16",
         // "agentId" : "emeroad-pc",
@@ -105,7 +105,8 @@ public class SpanAligner2 {
             logger.warn("collectorAcceptTime match collision. size:{} collectorAcceptTime:{} allSpan:{}", startMatchSize, collectorAcceptTime, spanList);
             throw new IllegalStateException("startTime match collision size:" + startMatchSize + " collectorAcceptTime:" + collectorAcceptTime);
         }
-        // 여기서 다음상황으로 더 정확하게 매치가 가능한가? 마땅히 call stack을 랜더링 할수 있는 방법 없음
+        // can we do better match like below?
+        // there is no definitive answer for do call stack rendering
         logger.warn("collectorAcceptTime match not found. size:{} collectorAcceptTime:{} allSpan:{}", startMatchSize, collectorAcceptTime, spanList);
         throw new IllegalStateException("startTime match not found startTime size:" + startMatchSize + " collectorAcceptTime:" + collectorAcceptTime);
     }
@@ -151,7 +152,7 @@ public class SpanAligner2 {
         if (logger.isDebugEnabled()) {
             logger.debug("span type:{} depth:{} spanDepth:{} ", currentDepth, span.getServiceType(), spanDepth);
         }
-		
+
 		SpanAlign spanAlign = new SpanAlign(currentDepth, span);
 		container.add(spanAlign);
 
@@ -159,9 +160,9 @@ public class SpanAligner2 {
         if (spanEventBoList == null) {
             return;
         }
-        
+
         spanAlign.setHasChild(true);
-        
+
 		for (SpanEventBo spanEventBo : spanEventBoList) {
 			if (spanEventBo. getDepth() != -1) {
 				currentDepth = spanDepth + spanEventBo.getDepth();
@@ -189,7 +190,7 @@ public class SpanAligner2 {
         logger.debug("populate end");
 	}
 
-    // nextSpan의 충돌 까지 해결한다.
+    // fix nextSpan collision problem
     private SpanBo getNextSpan(SpanBo span, SpanEventBo beforeSpanEventBo, List<SpanBo> nextSpanBoList) {
         if (logger.isDebugEnabled()) {
             logger.debug("beforeSpanEvent:{}, nextSpanBoList:{}", beforeSpanEventBo, nextSpanBoList);
@@ -197,15 +198,16 @@ public class SpanAligner2 {
         if (nextSpanBoList.size() == 1) {
             return nextSpanBoList.get(0);
         } else if(nextSpanBoList.size() > 1) {
-            // 최대한 비슷한 매칭을 시도한다.
+            // try best similar match
 //            return spanBos.get(0);
             long spanEventBoStartTime = span.getStartTime() + beforeSpanEventBo.getStartElapsed();
 
             SpanIdMatcher spanIdMatcher = new SpanIdMatcher(nextSpanBoList);
-            // 전체를 보지 않고 일부만 보고 유사도를 측정하므로, 패킷 lost등에 매우 취약함. 전체를 보고 근사도를 추가 분석하는 방법이 강구되어야 될것 같음.
+            // very susceptible to things like packet loss due to similarilty match based on restricted set of data
+            // TODO: need to find a better way to calc similarity based on entire data
             SpanBo matched = spanIdMatcher.approximateMatch(spanEventBoStartTime);
             if (matched == null) {
-                // match되는 span을 찾을수 없음.
+                // no matching span
                 return null;
             }
             List<SpanBo> other = spanIdMatcher.other();

web/src/main/java/com/navercorp/pinpoint/web/calltree/span/SpanIdMatcher.java

@@ -39,7 +39,7 @@ public class SpanIdMatcher {
     }
 
     public SpanBo approximateMatch(long spanEventBoStartTime) {
-        // 매칭 알고리즘이 있어야 함.
+        // TODO: we need mathing algorithm
         List<WeightSpanBo> weightSpanList = computeWeight(spanEventBoStartTime);
         if (weightSpanList.size() == 0) {
             return null;
@@ -82,8 +82,9 @@ public class SpanIdMatcher {
         if (minValue.size() == 1) {
             return minValue.get(0);
         }
-        // 2개 이상일 경우일단 그냥 앞선 데이터를 던짐.
-        // 뭔가 로그 필요.
+
+        // returns the first data when more than one
+        // TODO: we probably log this
         return minValue.get(0);
     }
 
@@ -94,7 +95,7 @@ public class SpanIdMatcher {
             long distance = startTime - spanEventBoStartTime;
             long weightDistance = getWeightDistance(distance);
             if (weightDistance > MAX_EXCLUDE_WEIGHT) {
-                // MAX WEIGHT보다 가중치가 높을 경우. 분실된 케이스 일수 있으므로 그냥 버린다.
+                // if higher than MAX WEIGHT, most likely missing case. just drop it
                 continue;
             }
             weightSpanList.add(new WeightSpanBo(weightDistance, next));
@@ -104,12 +105,13 @@ public class SpanIdMatcher {
 
     private long getWeightDistance(long distance) {
         if (distance >= 0) {
-            // 양수일 경우
+            // positive number
             return distance;
         } else {
-            // 음수일 경우 패널티를 둔다. 네트워크 타임 동기화 시간이 길지 않을 경우 음수가  매치될 확율은 매우 적어야 한다.
-            // 차라리 jvm gc등으로 인해 양수 값이 많이 차이 날수 있지. 음수값이 매치될 가능성은 매우낮다고 봐야 한다.
-            // 네트워크 싱크 시간?? 오차 등을 추가로 더하면 될거 같은데. 모르니깐 대충 더하자. 패널티는 1초
+            // give a penalty when negative
+            // if time skew due to network time sync problem is not big, it is highly unlikely to match a negative number
+            // it actually is more likely to get higher positive number diff due to JVM GC.
+            // TODO: need to adjust for network sync time diff. penalty is just set to 1 second
             distance = Math.abs(distance);
             return (distance * 2) + 1000;
         }

web/src/main/java/com/navercorp/pinpoint/web/cluster/ClusterManager.java

@@ -26,7 +26,7 @@ public interface ClusterManager {
 	boolean registerWebCluster(String zNodeName, byte[] contents);
 
 	void close();
-	
+
 	List<String> getRegisteredAgentList(String applicationName, String agentId, long startTimeStamp);
 
 }

web/src/main/java/com/navercorp/pinpoint/web/cluster/CollectorClusterInfoRepository.java

@@ -35,7 +35,7 @@ public class CollectorClusterInfoRepository {
 	private final Map<String, Map<String, String>> repository = new HashMap<String, Map<String, String>>();
 
 	private final Object lock = new Object();
-	
+
 	public void put(String id, byte[] data) {
 		synchronized (lock) {
 			Map<String, String> newMap = new HashMap<String, String>();
@@ -49,7 +49,7 @@ public class CollectorClusterInfoRepository {
 
 				newMap.put(profilerInfo, id);
 			}
-			
+
 			repository.put(id, newMap);
 		}
 	}
@@ -93,7 +93,7 @@ public class CollectorClusterInfoRepository {
 
 		return key.toString();
 	}
-	
+
 	@Override
 	public String toString() {
 		return repository.toString();

web/src/main/java/com/navercorp/pinpoint/web/cluster/zookeeper/ZookeeperClient.java

@@ -46,23 +46,23 @@ public class ZookeeperClient {
 
 	private final Logger logger = LoggerFactory.getLogger(this.getClass());
 
-	// 쥬키퍼 클라이언트는 스레드 세이프함
+	// ZK client is thread-safe
 	private final ZookeeperClusterManager manager;
 
 	private final ZooKeeper zookeeper;
 	private final AtomicBoolean clientState = new AtomicBoolean(true);
 
-	// 데이터를 이친구가 다가지고 있어야 할 거 같은데;
+	// hmm this structure should contain all necessary information
 	public ZookeeperClient(String hostPort, int sessionTimeout, ZookeeperClusterManager manager) throws KeeperException, IOException, InterruptedException {
 		this.manager = manager;
 		zookeeper = new ZooKeeper(hostPort, sessionTimeout, this.manager); // server
 	}
-	
+
 	/**
-	 * path의 가장마지막에 있는 node는 생성하지 않는다. 
-	 * 
-	 * @throws PinpointZookeeperException 
-	 * @throws InterruptedException 
+	 * do not create node in path suffix
+	 *
+	 * @throws PinpointZookeeperException
+	 * @throws InterruptedException
 	 */
 	public void createPath(String path) throws PinpointZookeeperException, InterruptedException {
 		checkState();
@@ -86,14 +86,13 @@ public class ZookeeperClient {
 			} catch (KeeperException exception) {
 				if (exception.code() != Code.NODEEXISTS) {
 					handleException(exception);
-				} 
+				}
 			}
 
 		} while (pos < path.length());
 	}
 
-	// 정확히 동일한 노드가 생성되어 있는지 확인하려면
-	// 내부의 컨텐츠 검사도 해야됨
+	// we need deep node inspection for verification purpose (node content)
 	public String createNode(String znodePath, byte[] data, CreateMode createMode) throws PinpointZookeeperException, InterruptedException {
 		checkState();
 
@@ -107,11 +106,11 @@ public class ZookeeperClient {
 		} catch (KeeperException exception) {
 			if (exception.code() != Code.NODEEXISTS) {
 				handleException(exception);
-			} 
+			}
 		}
 		return znodePath;
 	}
-	
+
 	public List<String> getChildren(String path, boolean watch) throws PinpointZookeeperException, InterruptedException {
 		checkState();
 
@@ -122,10 +121,10 @@ public class ZookeeperClient {
 				handleException(exception);
 			}
 		}
-		
+
 		return Collections.emptyList();
 	}
-	
+
 	public byte[] getData(String path) throws PinpointZookeeperException, InterruptedException {
 		return getData(path, false);
 	}
@@ -138,11 +137,11 @@ public class ZookeeperClient {
 		} catch (KeeperException exception) {
 			handleException(exception);
 		}
-		
+
 		throw new UnknownException("UnknownException.");
 	}
 
-	
+
 	public void delete(String path) throws PinpointZookeeperException, InterruptedException {
 		checkState();
 
@@ -151,7 +150,7 @@ public class ZookeeperClient {
 		} catch (KeeperException exception) {
 			if (exception.code() != Code.NONODE) {
 				handleException(exception);
-			} 
+			}
 		}
 	}
 
@@ -166,7 +165,7 @@ public class ZookeeperClient {
 		} catch (KeeperException exception) {
 			if (exception.code() != Code.NODEEXISTS) {
 				handleException(exception);
-			} 
+			}
 		}
 		return true;
 	}
@@ -200,7 +199,7 @@ public class ZookeeperClient {
 				throw new UnknownException(keeperException.getMessage(), keeperException);
 			}
 	}
-	
+
 	public void close() {
 		if (clientState.compareAndSet(true, false)) {
 			if (zookeeper != null) {

web/src/main/java/com/navercorp/pinpoint/web/cluster/zookeeper/ZookeeperClusterManager.java

@@ -61,23 +61,22 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 	private final ZookeeperClient client;
 
 	private final int retryInterval;
-	
+
 	private final Timer timer;
 
 	private final AtomicReference<PushWebClusterJob> job = new AtomicReference<ZookeeperClusterManager.PushWebClusterJob>();
 
 	private final CollectorClusterInfoRepository collectorClusterInfo = new CollectorClusterInfoRepository();
-	
+
 	public ZookeeperClusterManager(String zookeeperAddress, int sessionTimeout, int retryInterval) throws KeeperException, IOException, InterruptedException {
 		this.client = new ZookeeperClient(zookeeperAddress, sessionTimeout, this);
 		this.retryInterval = retryInterval;
-		// 등록이 실패하였을때 생성하게 하는게 나을수도 있음
+		// it could be better to create upon failure
 		this.timer = createTimer();
 	}
 
-	// 등록이 실패해도 계속 시도 (주기는 기본 1분)
-	// 크게 부하가 가는 작업이 아니며, 
-	// 실패할 경우 계속 로그를 출력
+	// Retry upon failure (1 min retry period)
+	// not too much overhead, just logging
 	@Override
 	public boolean registerWebCluster(String zNodeName, byte[] contents) {
 		String zNodePath = bindingPathAndZnode(PINPOINT_WEB_CLUSTER_PATh, zNodeName);
@@ -90,12 +89,12 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 			return false;
 		}
 
-		// 스케쥴로 라도 등록하면 성공
+		// successful even for schedular registration completion
 		if (!isConnected()) {
 			logger.info("Zookeeper is Disconnected.");
 			return true;
 		}
-		
+
 		if (!syncWebCluster(job)) {
 			timer.newTimeout(job, job.getRetryInterval(), TimeUnit.MILLISECONDS);
 		}
@@ -106,15 +105,15 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 	@Override
 	public void process(WatchedEvent event) {
 		logger.info("Zookeepr Event({}) ocurred.", event);
-		
+
 		KeeperState state = event.getState();
 		EventType eventType = event.getType();
 		String path = event.getPath();
 
 		boolean result = false;
-		
-		// 상태가 되면 ephemeral 노드가 사라짐
-		// 문서에 따라 자동으로 연결이 되고, 연결되는 이벤트는 process에서 감지가 됨
+
+		// when this happens, ephemeral node disappears
+		// reconnects automatically, and process gets notified for all events
 		if (state == KeeperState.Disconnected || state == KeeperState.Expired) {
 			result = handleDisconnected();
 		} else if ((state == KeeperState.SyncConnected || state == KeeperState.NoSyncConnected) && eventType == EventType.None) {
@@ -126,24 +125,24 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 		} else if ((state == KeeperState.SyncConnected || state == KeeperState.NoSyncConnected) && eventType == EventType.NodeDataChanged) {
 			result = handleNodeDataChanged(path);
 		}
-		
+
 		if (result) {
-			logger.info("Zookeeper Event({}) successed.", event); 
+			logger.info("Zookeeper Event({}) successed.", event);
 		} else {
-			logger.info("Zookeeper Event({}) failed.", event); 
+			logger.info("Zookeeper Event({}) failed.", event);
 		}
 	}
-	
+
 	private boolean handleDisconnected() {
 		connected.compareAndSet(true, false);
 		collectorClusterInfo.clear();
 		return true;
 	}
-	
+
 	private boolean handleConnected() {
 		boolean result = true;
-		
-		// 이전상태가 RUN일수 있기 때문에 유지해도 됨
+
+		// is it ok to keep this since previous condition was possibly RUN
 		boolean changed = connected.compareAndSet(false, true);
 		if (changed) {
 			PushWebClusterJob job = this.job.get();
@@ -153,7 +152,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 					result = false;
 				}
 			}
-			
+
 			if (!syncCollectorCluster()) {
 				timer.newTimeout(new FetchCollectorClusterJob(), SYNC_INTERVAL_TIME_MILLIS, TimeUnit.MILLISECONDS);
 				result = false;
@@ -161,10 +160,10 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 		} else {
 			result = false;
 		}
-		
+
 		return result;
 	}
-	
+
 	private boolean handleNodeChildrenChanged(String path) {
 		if (PINPOINT_COLLECTOR_CLUSTER_PATH.equals(path)) {
 			if (syncCollectorCluster()) {
@@ -172,10 +171,10 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 			}
 			timer.newTimeout(new FetchCollectorClusterJob(), SYNC_INTERVAL_TIME_MILLIS, TimeUnit.MILLISECONDS);
 		}
-		
+
 		return false;
 	}
-	
+
 	private boolean handleNodeDeleted(String path) {
 		if (path != null) {
 			String id = extractCollectorClusterId(path);
@@ -186,18 +185,18 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 		}
 		return false;
 	}
-	
+
 	private boolean handleNodeDataChanged(String path) {
 		if (path != null) {
 			String id = extractCollectorClusterId(path);
 			if (id != null) {
 				if (syncCollectorCluster(id)) {
 					return true;
-				} 
+				}
 				timer.newTimeout(new FetchCollectorClusterJob(), SYNC_INTERVAL_TIME_MILLIS, TimeUnit.MILLISECONDS);
 			}
 		}
-		
+
 		return false;
 	}
 
@@ -216,7 +215,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 	public List<String> getRegisteredAgentList(String applicationName, String agentId, long startTimeStamp) {
 		return collectorClusterInfo.get(applicationName, agentId, startTimeStamp);
 	}
-	
+
 	private Timer createTimer() {
 		HashedWheelTimer timer = TimerFactory.createHashedWheelTimer("Pinpoint-Web-Cluster-Timer", 100, TimeUnit.MILLISECONDS, 512);
 		timer.start();
@@ -232,7 +231,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 				client.createPath(zNodePath);
 			}
 
-			// 쥬키퍼의 zNode는 ip:port 형태의 이름으로 만들수 있음
+			// ip:port zNode naming scheme
 			String nodeName = client.createNode(zNodePath, contents, CreateMode.EPHEMERAL);
 			logger.info("Register Web Cluster Zookeeper UniqPath = {}.", zNodePath);
 			return true;
@@ -257,12 +256,12 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 
 		return fullPath.toString();
 	}
-	
+
 	private String extractCollectorClusterId(String path) {
 		int index  = path.indexOf(PINPOINT_COLLECTOR_CLUSTER_PATH);
-		
+
 		int startPosition = index + PINPOINT_COLLECTOR_CLUSTER_PATH.length() + 1;
-		
+
 		if (path.length() > startPosition) {
 			String id = path.substring(startPosition);
 			return id;
@@ -270,11 +269,11 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 
 		return null;
 	}
-	
+
 	private boolean syncCollectorCluster() {
 		synchronized (this) {
 			Map<String, byte[]> map = getCollectorData();
-			
+
 			if (map == null) {
 				return false;
 			}
@@ -282,7 +281,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 			for (Map.Entry<String, byte[]> entry : map.entrySet()) {
 				String key = entry.getKey();
 				byte[] value = entry.getValue();
-				
+
 				String id = extractCollectorClusterId(key);
 				if (id == null) {
 					logger.error("Illegal Collector Path({}) finded.", key);
@@ -290,17 +289,17 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 				}
 				collectorClusterInfo.put(id, value);
 			}
-			
+
 			return true;
 		}
 	}
-	
+
 	private boolean syncCollectorCluster(String id) {
 	    String path = bindingPathAndZnode(PINPOINT_COLLECTOR_CLUSTER_PATH, id);
 		synchronized (this) {
 			try {
 				byte[] data = client.getData(path, true);
-				
+
 				collectorClusterInfo.put(id, data);
 				return true;
 			} catch(NoNodeException e) {
@@ -309,7 +308,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 			} catch (Exception e) {
 				logger.warn(e.getMessage(), e);
 			}
-			
+
 			return false;
 		}
 	}
@@ -319,19 +318,19 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 			List<String> collectorList = client.getChildren(PINPOINT_COLLECTOR_CLUSTER_PATH, true);
 
 			Map<String, byte[]> map = new HashMap<String, byte[]>();
-			
+
 			for (String collector : collectorList) {
 				String node = bindingPathAndZnode(PINPOINT_COLLECTOR_CLUSTER_PATH, collector);
-				
+
 				byte[] data = client.getData(node, true);
 				map.put(node, data);
 			}
-			
+
 			return map;
 		} catch (Exception e) {
 			logger.warn(e.getMessage(), e);
 		}
-		
+
 		return null;
 	}
 
@@ -340,7 +339,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 		private final String znodeName;
 		private final byte[] contents;
 		private final int retryInterval;
-		
+
 		public PushWebClusterJob(String znodeName, byte[] contents, int retryInterval) {
 			this.znodeName = znodeName;
 			this.contents = contents;
@@ -358,7 +357,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 		public int getRetryInterval() {
 			return retryInterval;
 		}
-		
+
 		@Override
 		public String toString() {
 			StringBuilder toString = new StringBuilder();
@@ -371,19 +370,19 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 		@Override
 		public void run(Timeout timeout) throws Exception {
 			logger.info("Reservation Job({}) started.", this.getClass().getSimpleName());
-			
+
 			if (!isConnected()) {
 				return;
 			}
-			
+
 			if (!syncWebCluster(this)) {
 				timer.newTimeout(this, getRetryInterval(), TimeUnit.MILLISECONDS);
 			}
 		}
 	}
-	
+
 	class FetchCollectorClusterJob implements TimerTask {
-		
+
 		@Override
 		public void run(Timeout timeout) throws Exception {
 			logger.info("Reservation Job({}) started.", this.getClass().getSimpleName());
@@ -391,7 +390,7 @@ public class ZookeeperClusterManager implements ClusterManager, Watcher {
 			if (!isConnected()) {
 				return;
 			}
-			
+
 			if (!syncCollectorCluster()) {
 				timer.newTimeout(new FetchCollectorClusterJob(), SYNC_INTERVAL_TIME_MILLIS, TimeUnit.MILLISECONDS);
 			}

web/src/main/java/com/navercorp/pinpoint/web/cluster/zookeeper/exception/PinpointZookeeperException.java

@@ -20,7 +20,7 @@ package com.navercorp.pinpoint.web.cluster.zookeeper.exception;
  * @author koo.taejin
  */
 public class PinpointZookeeperException extends Exception {
-	
+
 	public PinpointZookeeperException() {
 	}
 

web/src/main/java/com/navercorp/pinpoint/web/config/WebConfig.java

@@ -29,10 +29,10 @@ import org.springframework.beans.factory.annotation.Value;
 public class WebConfig {
 
 	private final Logger logger = LoggerFactory.getLogger(this.getClass());
-	
+
 	@Value("#{pinpointWebProps['cluster.enable'] ?: false}")
 	private boolean clusterEnable;
-	
+
 	@Value("#{pinpointWebProps['cluster.web.tcp.port'] ?: 0}")
 	private int clusterTcpPort;
 
@@ -44,7 +44,7 @@ public class WebConfig {
 
 	@Value("#{pinpointWebProps['cluster.zookeeper.retry.interval'] ?: 60000}")
 	private int clusterZookeeperRetryInterval;
-	
+
 	@PostConstruct
 	public void validation() {
 		if (isClusterEnable()) {
@@ -55,7 +55,7 @@ public class WebConfig {
 			assertPositiveNumber(clusterZookeeperSessionTimeout);
 			assertPositiveNumber(clusterZookeeperRetryInterval);
 		}
-		
+
 		logger.info("{}", toString());
 	}
 
@@ -63,15 +63,15 @@ public class WebConfig {
 		if (port > 0 && 65535 > port) {
 			return true;
 		}
-		
+
 		throw new IllegalArgumentException("Invalid Port =" + port);
 	}
-	
+
 	private boolean assertPositiveNumber(int number) {
 		if (number >= 0) {
 			return true;
 		}
-		
+
 		throw new IllegalArgumentException("Invalid Positive Number =" + number);
 	}
 
@@ -90,7 +90,7 @@ public class WebConfig {
 	public int getClusterZookeeperSessionTimeout() {
 		return clusterZookeeperSessionTimeout;
 	}
-	
+
 	@Override
 	public String toString() {
 		return "WebConfig [clusterEnable=" + clusterEnable

web/src/main/java/com/navercorp/pinpoint/web/controller/BusinessTransactionController.java

@@ -70,8 +70,8 @@ public class BusinessTransactionController {
     private FilterBuilder filterBuilder;
 
     /**
-	 * applicationname에서 from ~ to 시간대에 수행된 URL을 조회한다.
-	 * 
+	 * executed URLs in applicationname query within from ~ to timeframe
+	 *
 	 * @param model
 	 * @param applicationName
 	 * @param from
@@ -83,13 +83,13 @@ public class BusinessTransactionController {
     @ResponseBody
 	public Model getBusinessTransactionsData(Model model,
 											@RequestParam("application") String applicationName,
-											@RequestParam("from") long from, 
+											@RequestParam("from") long from,
 											@RequestParam("to") long to,
 											@RequestParam(value = "filter", required = false) String filterText,
 											@RequestParam(value = "limit", required = false, defaultValue = "10000") int limit) {
         limit = LimitUtils.checkRange(limit);
 		Range range = new Range(from, to);
-		// TOOD 구조개선을 위해 server map조회 로직 분리함, 임시로 분리한 상태이고 개선이 필요하다.
+		// TODO more refactoring needed: partially separated out server map lookup logic.
 		LimitedScanResult<List<TransactionId>> traceIdList = filteredMapService.selectTraceIdsFromApplicationTraceIndex(applicationName, range, limit);
 
 		Filter filter = filterBuilder.build(filterText);
@@ -114,7 +114,7 @@ public class BusinessTransactionController {
 	@RequestMapping(value = "/lastTransactionList", method = RequestMethod.GET)
     @ResponseBody
 	public Model getLastBusinessTransactionsData(Model model, HttpServletResponse response,
-											@RequestParam("application") String applicationName, 
+											@RequestParam("application") String applicationName,
 											@RequestParam("period") long period,
 											@RequestParam(value = "filter", required = false) String filterText,
 											@RequestParam(value = "limit", required = false, defaultValue = "10000") int limit) {
@@ -125,7 +125,7 @@ public class BusinessTransactionController {
 	}
 
     /**
-     * 선택한 하나의 Transaction 정보 조회.
+		 * info lookup for a selected transaction
      *
      * @param traceIdParam
      * @param focusTimestamp

web/src/main/java/com/navercorp/pinpoint/web/controller/CommandController.java

@@ -54,8 +54,8 @@ import com.navercorp.pinpoint.web.server.PinpointSocketManager;
 @RequestMapping("/command")
 public class CommandController {
 
-	// FIX ME: 단순히 연동 테스트를 위해서 만든것
-	// 나중에 api같은게 정해지면 그때 이를 이용해서 정상적으로 api를 만들면 될듯
+	// FIX ME: created for a simple ping/pong test for now
+	// need a formal set of APIs and proper code
 
 	private final Logger logger = LoggerFactory.getLogger(this.getClass());
 

web/src/main/java/com/navercorp/pinpoint/web/controller/FilteredMapController.java

@@ -56,8 +56,8 @@ public class FilteredMapController {
     private FilterBuilder filterBuilder;
 
 	/**
-	 * 필터가 적용된 서버맵의 FROM ~ TO기간의 데이터 조회
-	 * 
+   * filtered server map data query within from ~ to timeframe
+	 *
 	 * @param applicationName
 	 * @param serviceTypeCode
 	 * @param from
@@ -79,18 +79,17 @@ public class FilteredMapController {
 											@RequestParam(value = "limit", required = false, defaultValue = "10000") int limit) {
         limit = LimitUtils.checkRange(limit);
         final Filter filter = filterBuilder.build(filterText, filterHint);
-        // scan을 해야 될 토탈 범위
         final Range range = new Range(from, to);
         final LimitedScanResult<List<TransactionId>> limitedScanResult = filteredMapService.selectTraceIdsFromApplicationTraceIndex(applicationName, range, limit);
 
         final long lastScanTime = limitedScanResult.getLimitedTime();
-        // 원본 범위, 시계열 차트의 sampling을 하려면 필요함.
+        // original range: needed for visual chart data sampling
         final Range originalRange = new Range(from, originTo);
-        // 정확히 스캔된 범위가 어디까지 인지 알기 위해서 필요함.
+        // needed to figure out already scanned ranged
         final Range scannerRange = new Range(lastScanTime, to);
         logger.debug("originalRange:{} scannerRange:{} ", originalRange, scannerRange);
         ApplicationMap map = filteredMapService.selectApplicationMap(limitedScanResult.getScanData(), originalRange, scannerRange, filter);
-		
+
         if (logger.isDebugEnabled()) {
             logger.debug("getFilteredServerMapData range scan(limit:{}) range:{} lastFetchedTimestamp:{}", limit, range.prettyToString(), DateUtils.longToDateStr(lastScanTime));
         }
@@ -99,10 +98,11 @@ public class FilteredMapController {
         mapWrap.setLastFetchedTimestamp(lastScanTime);
         return mapWrap;
 	}
-	
+
 	/**
-	 * 필터가 적용된 서버맵의 Period before 부터 현재시간까지의 데이터 조회.
-	 * 
+   * filtered server map data query for the last "Period" up to now
+   *
+	 *
 	 * @param applicationName
 	 * @param serviceTypeCode
 	 * @param filterText
@@ -122,9 +122,10 @@ public class FilteredMapController {
 
 		long to = TimeUtils.getDelayLastTime();
 		long from = to - period;
-        // TODO 실시간 조회가 현재 disable이므로 to to로 수정하였음. 이것도 추가적으로 @RequestParam("originTo")가 필요할수 있음.
+    // TODO: since realtime query is enabled for now, calling parameters are fixed as "..., to, to, ..."
+    // may need additional @RequestParam("originTo")
 		return getFilteredServerMapData(applicationName, serviceTypeCode, from, to, to, filterText, filterHint, limit);
 	}
 
 
-}
+}

web/src/main/java/com/navercorp/pinpoint/web/controller/MainController.java

@@ -57,4 +57,4 @@ public class MainController {
 	public ServerTime getServerTime() {
 		return new ServerTime();
 	}
-}
+}

web/src/main/java/com/navercorp/pinpoint/web/controller/MapController.java

@@ -59,7 +59,7 @@ public class MapController {
     private Limiter dateLimit;
 
 	/**
-	 * FROM ~ TO기간의 서버 맵 데이터 조회
+   * Server map data query within from ~ to timeframe
 	 *
 	 * @param applicationName
 	 * @param serviceTypeCode
@@ -85,8 +85,8 @@ public class MapController {
 	}
 
 	/**
-	 * Period before 부터 현재시간까지의 서버맵 조회.
-	 * 
+   * Server map data query for the last "Period" timeframe
+	 *
 	 * @param applicationName
 	 * @param serviceTypeCode
 	 * @param period
@@ -98,16 +98,16 @@ public class MapController {
 										@RequestParam("applicationName") String applicationName,
 										@RequestParam("serviceTypeCode") short serviceTypeCode,
 										@RequestParam("period") long period) {
-		
+
 		long to = TimeUtils.getDelayLastTime();
 		long from = to - period;
 		return getServerMapData(applicationName, serviceTypeCode, from, to);
 	}
 
 	/**
-     * 맵에서 직접 찍어오는걸로 변경시 잘 사용하지 않는 API가 될것임.
-	 * 필터가 사용되지 않은 서버맵의 연결선을 통과하는 요청의 통계정보 조회
-	 * 
+   * Possible deprecation expected when UI change push forward to pick a map first from UI
+   * Unfiltered server map request data query
+	 *
 	 * @param model
 	 * @param from
 	 * @param to
@@ -127,32 +127,32 @@ public class MapController {
 									@RequestParam("targetApplicationName") String targetApplicationName,
 									@RequestParam("targetServiceType") short targetServiceType) {
 
-        final Application sourceApplication = new Application(sourceApplicationName, sourceServiceType);
-        final Application destinationApplication = new Application(targetApplicationName, targetServiceType);
-        final Range range = new Range(from, to);
+    final Application sourceApplication = new Application(sourceApplicationName, sourceServiceType);
+    final Application destinationApplication = new Application(targetApplicationName, targetServiceType);
+    final Range range = new Range(from, to);
 
-        NodeHistogram nodeHistogram = mapService.linkStatistics(sourceApplication, destinationApplication, range);
+    NodeHistogram nodeHistogram = mapService.linkStatistics(sourceApplication, destinationApplication, range);
 
 		model.addAttribute("range", range);
 
-        model.addAttribute("sourceApplication", sourceApplication);
+    model.addAttribute("sourceApplication", sourceApplication);
 
-        model.addAttribute("targetApplication", destinationApplication);
+    model.addAttribute("targetApplication", destinationApplication);
 
-        Histogram applicationHistogram = nodeHistogram.getApplicationHistogram();
+    Histogram applicationHistogram = nodeHistogram.getApplicationHistogram();
 		model.addAttribute("linkStatistics", applicationHistogram);
 
 
-        List<ResponseTimeViewModel> applicationTimeSeriesHistogram = nodeHistogram.getApplicationTimeHistogram();
-        String applicationTimeSeriesHistogramJson = null;
-        try {
-            applicationTimeSeriesHistogramJson = MAPPER.writeValueAsString(applicationTimeSeriesHistogram);
-        } catch (IOException e) {
-            throw new RuntimeException(e.getMessage(), e);
-        }
-        model.addAttribute("timeSeriesHistogram", applicationTimeSeriesHistogramJson);
+    List<ResponseTimeViewModel> applicationTimeSeriesHistogram = nodeHistogram.getApplicationTimeHistogram();
+    String applicationTimeSeriesHistogramJson = null;
+    try {
+        applicationTimeSeriesHistogramJson = MAPPER.writeValueAsString(applicationTimeSeriesHistogram);
+    } catch (IOException e) {
+        throw new RuntimeException(e.getMessage(), e);
+    }
+    model.addAttribute("timeSeriesHistogram", applicationTimeSeriesHistogramJson);
 
-        // 결과의 from, to를 다시 명시해야 되는듯 한데. 현재는 그냥 요청 데이터를 그냥 주는것으로 보임.
+    // looks like we need to specify "from, to" to the result. but data got passed thru as it is.
 		model.addAttribute("resultFrom", from);
 		model.addAttribute("resultTo", to);
 
@@ -161,4 +161,4 @@ public class MapController {
 	}
 
     private final static ObjectMapper MAPPER = new ObjectMapper();
-}
+}

web/src/main/java/com/navercorp/pinpoint/web/controller/ScatterChartController.java

@@ -47,7 +47,7 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.servlet.ModelAndView;
 
 /**
- * 
+ *
  * @author netspider
  * @author emeroad
  */
@@ -58,7 +58,7 @@ public class ScatterChartController {
 
 	@Autowired
 	private ScatterChartService scatter;
-	
+
 	@Autowired
 	private FilteredMapService flow;
 
@@ -73,9 +73,9 @@ public class ScatterChartController {
 	@RequestMapping(value = "/scatterpopup", method = RequestMethod.GET)
 	public String scatterPopup(Model model,
 								@RequestParam("application") String applicationName,
-								@RequestParam("from") long from, 
-								@RequestParam("to") long to, 
-								@RequestParam("period") long period, 
+								@RequestParam("from") long from,
+								@RequestParam("to") long to,
+								@RequestParam("period") long period,
 								@RequestParam("usePeriod") boolean usePeriod,
 								@RequestParam(value = "filter", required = false) String filterText) {
 		model.addAttribute("applicationName", applicationName);
@@ -88,21 +88,21 @@ public class ScatterChartController {
 	}
 
 	/**
-	 * 
+	 *
 	 * @param applicationName
 	 * @param from
 	 * @param to
 	 * @param limit
-	 *            한번에 조회 할 데이터의 크기, 조회 결과가 이 크기를 넘어가면 limit개만 반환한다. 나머지는 다시 요청해서
-	 *            조회해야 한다.
+	 *            max number of data return. if the requested data exceed this limit, we need additional calls to
+	 * 						fetch the rest of the data
 	 * @return
 	 */
 	@RequestMapping(value = "/getScatterData", method = RequestMethod.GET)
 	public ModelAndView getScatterData(
 								@RequestParam("application") String applicationName,
-								@RequestParam("from") long from, 
+								@RequestParam("from") long from,
 								@RequestParam("to") long to,
-								@RequestParam("limit") int limit, 
+								@RequestParam("limit") int limit,
 								@RequestParam(value = "filter", required = false) String filterText,
 								@RequestParam(value = "_callback", required = false) String jsonpCallback,
 								@RequestParam(value = "v", required = false, defaultValue = "2") int version) {
@@ -111,7 +111,7 @@ public class ScatterChartController {
 		StopWatch watch = new StopWatch();
 		watch.start("selectScatterData");
 
-        // TODO 레인지 체크 확인 exception 발생, from값이 to 보다 더 큼.
+				// TODO range check verification exception occurs. "from" is bigger than "to"
         final Range range = Range.createUncheckedRange(from, to);
         logger.debug("fetch scatter data. {}, LIMIT={}, FILTER={}", range, limit, filterText);
 
@@ -135,7 +135,8 @@ public class ScatterChartController {
 
         final List<TransactionId> traceIdList = limitedScanResult.getScanData();
         logger.trace("submitted transactionId count={}", traceIdList.size());
-        // TODO sorted만 하는가? tree기반으로 레인지 체크하도록 하고 삭제하도록 하자.
+
+				// TODO just need sorted?  we need range check with tree-based structure.
         SortedSet<TransactionId> traceIdSet = new TreeSet<TransactionId>(traceIdList);
         logger.debug("unified traceIdSet size={}", traceIdSet.size());
 
@@ -182,8 +183,8 @@ public class ScatterChartController {
     }
 
     /**
-	 * NOW 버튼을 눌렀을 때 scatter 데이터 조회.
-	 * 
+	 * scatter chart data query for "NOW" button
+	 *
 	 * @param applicationName
 	 * @param limit
 	 * @return
@@ -200,13 +201,14 @@ public class ScatterChartController {
 
         long to = TimeUtils.getDelayLastTime();
 		long from = to - period;
-		// TODO version은 임시로 사용됨. template변경과 서버개발을 동시에 하려고..
+
+		// TODO versioning is temporary. to sync template change and server dev
 		return getScatterData(applicationName, from, to, limit, filterText, jsonpCallback, version);
 	}
 
 	/**
-	 * scatter에서 점 여러개를 선택했을 때 점에 대한 정보를 조회한다.
-	 * 
+	 * selected points from scatter chart data query
+	 *
 	 * @param model
 	 * @param request
 	 * @param response
@@ -242,14 +244,14 @@ public class ScatterChartController {
         logger.debug("query:{}", query);
         return query;
     }
-    
+
     /**
-     * scatter chart에서 선택한 범위에 속하는 트랜잭션 목록을 조회
-     * 
+		 * trasaction list query for selected points in scatter chart
+     *
      * <pre>
      * TEST URL = http://localhost:7080/transactionmetadata2.pinpoint?application=FRONT-WEB&from=1394432299032&to=1394433498269&responseFrom=100&responseTo=200&responseOffset=100&limit=10
      * </pre>
-     * 
+     *
      * @param model
      * @param request
      * @param response
@@ -258,38 +260,40 @@ public class ScatterChartController {
 	@RequestMapping(value = "/transactionmetadata2", method = RequestMethod.GET)
 	public String getTransaction(Model model,
 								@RequestParam("application") String applicationName,
-								@RequestParam("from") long from, 
+								@RequestParam("from") long from,
 								@RequestParam("to") long to,
-								@RequestParam("responseFrom") int responseFrom, 
+								@RequestParam("responseFrom") int responseFrom,
 								@RequestParam("responseTo") int responseTo,
-								@RequestParam("limit") int limit, 
+								@RequestParam("limit") int limit,
 								@RequestParam(value = "offsetTime", required = false, defaultValue = "-1") long offsetTime,
 								@RequestParam(value = "offsetTransactionId", required = false) String offsetTransactionId,
 								@RequestParam(value = "offsetTransactionElapsed", required = false, defaultValue = "-1") int offsetTransactionElapsed,
 								@RequestParam(value = "filter", required = false) String filterText) {
 
 		limit = LimitUtils.checkRange(limit);
-		
+
 		StopWatch watch = new StopWatch();
-		watch.start("selectScatterData");		
+		watch.start("selectScatterData");
 
 		final SelectedScatterArea area = SelectedScatterArea.createUncheckedArea(from, to, responseFrom, responseTo);
         logger.debug("fetch scatter data. {}, LIMIT={}, FILTER={}", area, limit, filterText);
 
 		if (filterText == null) {
-			// limit에 걸려서 조회되지 않은 부분 우선 조회
+
+			// query data above "limit" first
 			TransactionId offsetId = null;
 			List<SpanBo> extraMetadata = null;
 			if (offsetTransactionId != null) {
 				offsetId = new TransactionId(offsetTransactionId);
-				
+
 				SelectedScatterArea extraArea = SelectedScatterArea.createUncheckedArea(offsetTime, offsetTime, responseFrom, responseTo);
 				List<Dot> extraAreaDotList = scatter.selectScatterData(applicationName, extraArea, offsetId, offsetTransactionElapsed, limit);
 				extraMetadata = scatter.selectTransactionMetadata(parseSelectTransaction(extraAreaDotList));
 				model.addAttribute("extraMetadata", extraMetadata);
 			}
-			
-			// limit에 걸려서 조회되지 않은 부분 조회 결과가 limit에 미치지 못하면 나머지 영역 추가 조회
+
+			// query data up to limit
+			// XXX extraMetadata.size() <= limit????
 			if (extraMetadata == null || extraMetadata.size() < limit) {
 				int newlimit = limit - ((extraMetadata == null) ? 0 : extraMetadata.size());
 				List<Dot> selectedDotList = scatter.selectScatterData(applicationName, area, null, -1, newlimit);
@@ -300,8 +304,8 @@ public class ScatterChartController {
 			final LimitedScanResult<List<TransactionId>> limitedScanResult = flow.selectTraceIdsFromApplicationTraceIndex(applicationName, area, limit);
 			final List<TransactionId> traceIdList = limitedScanResult.getScanData();
 			logger.trace("submitted transactionId count={}", traceIdList.size());
-			
-			// TODO sorted만 하는가? tree기반으로 레인지 체크하도록 하고 삭제하도록 하자.
+
+			// TODO: just sorted?  we need range check based on tree structure
 			SortedSet<TransactionId> traceIdSet = new TreeSet<TransactionId>(traceIdList);
 			logger.debug("unified traceIdSet size={}", traceIdSet.size());
 
@@ -310,10 +314,10 @@ public class ScatterChartController {
 
         watch.stop();
 		logger.info("Fetch scatterData time : {}ms", watch.getLastTaskTimeMillis());
-        
+
 		return "transactionmetadata2";
 	}
-	
+
 	private TransactionMetadataQuery parseSelectTransaction(List<Dot> dotList) {
 		TransactionMetadataQuery query = new TransactionMetadataQuery();
 		if (dotList == null) {
@@ -325,4 +329,4 @@ public class ScatterChartController {
 		logger.debug("query:{}", query);
 		return query;
 	}
-}
+}

web/src/main/java/com/navercorp/pinpoint/web/dao/hbase/HbaseAgentInfoDao.java

@@ -65,10 +65,10 @@ public class HbaseAgentInfoDao implements AgentInfoDao {
 
 
         logger.debug("get agentInfo with, agentId={}, {}", agentId, range);
-    	
+
         Scan scan = new Scan();
         scan.setCaching(20);
-        
+
 		long fromTime = TimeUtils.reverseTimeMillis(range.getTo());
 		long toTime = TimeUtils.reverseTimeMillis(1);
 
@@ -92,9 +92,9 @@ public class HbaseAgentInfoDao implements AgentInfoDao {
 					long startTime = TimeUtils.recoveryTimeMillis(reverseStartTime);
 					byte[] serializedAgentInfo = next.getValue(HBaseTables.AGENTINFO_CF_INFO, HBaseTables.AGENTINFO_CF_INFO_IDENTIFIER);
 					byte[] serializedServerMetaData = next.getValue(HBaseTables.AGENTINFO_CF_INFO, HBaseTables.AGENTINFO_CF_INFO_SERVER_META_DATA);
-					        
+
 					logger.debug("found={}, {}, start={}", found, range, startTime);
-					
+
 					if (found > 1 && startTime <= range.getFrom()) {
 						logger.debug("stop finding agentInfo.");
 						break;
@@ -108,7 +108,7 @@ public class HbaseAgentInfoDao implements AgentInfoDao {
 					    agentInfoBoBuilder.serverMetaData(new ServerMetaDataBo.Builder(serializedServerMetaData).build());
 					}
 					final AgentInfoBo agentInfoBo = agentInfoBoBuilder.build();
-					
+
 					logger.debug("found agentInfoBo {}", agentInfoBo);
 					result.add(agentInfoBo);
 				}
@@ -116,9 +116,9 @@ public class HbaseAgentInfoDao implements AgentInfoDao {
 				return result;
 			}
 		});
-        
+
         logger.debug("get agentInfo result, {}", found);
-        
+
         return found;
     }
 
@@ -158,15 +158,15 @@ public class HbaseAgentInfoDao implements AgentInfoDao {
                             agentInfoBoBuilder.serverMetaData(new ServerMetaDataBo.Builder(serializedServerMetaData).build());
                         }
                         final AgentInfoBo agentInfoBo = agentInfoBoBuilder.build();
-                        
+
                         logger.debug("agent:{} startTime find {}", agentId, startTime);
 
                         return agentInfoBo;
                     }
                 }
-                
+
                 logger.warn("agentInfo not found. agentId={}, time={}", agentId, currentTime);
-                
+
                 return null;
             }
         });