Tuning of metrics data to store
This removes data we don't really need, as well as making sure we don't overload any cache stores or databases.
See merge request !2265
This will be used to store/increment the total query/view rendering
timings on a per transaction basis. This in turn can greatly reduce the
amount of metrics stored.
Attempting to use the /projects/:id API by specifying :id in
"namespace/project" format would always result in a 404 if the namespace
contained a dot.
The reason? From http://guides.rubyonrails.org/routing.html#specifying-constraints:
"By default the :id parameter doesn't accept dots - this is because the dot is
used as a separator for formatted routes. If you need to use a dot within an
:id add a constraint which overrides this - for example id: /[^\/]+/ allows
anything except a slash."
Closes https://github.com/gitlabhq/gitlabhq/issues/9573
This particular setup had 3 problems:
1. Storing SQL queries as tags is very inefficient as InfluxDB ends up
indexing every query (and they can get pretty large). Storing these
as values instead means we can't always display the SQL as easily.
2. We already instrument ActiveRecord query methods, thus we already
have timing information about database queries.
3. SQL obfuscation is difficult to get right and I'd rather not expose
sensitive data by accident.
Nokogiri produces inefficient XPath expressions when given CSS
expressions such as "a.gfm". Luckily these expressions can be optimized
quite easily while still achieving the same results.
In the two cases where this optimization is applied the run time has
been reduced from around 170 ms to around 15 ms.
Around 300 ms (in total) would be spent in these delegated methods due
to the extra stuff ActiveSupport adds to the compiled methods. Because
these delegations are so simple we can just manually define the methods,
saving around 275 milliseconds.
While it's useful to keep track of the different versions (Ruby, GitLab,
etc) doing so for every point wastes disk space and possibly also RAM
(which InfluxDB is all to eager to gobble up). If we want to see the
performance differences between different GitLab versions simply looking
at the performance since the last release date should suffice.
This removes the need for Sidekiq and any overhead/problems introduced
by TCP. There are a few things to take into account:
1. When writing data to InfluxDB you may still get an error if the
server becomes unavailable during the write. Because of this we're
catching all exceptions and just ignore them (for now).
2. Writing via UDP apparently requires the timestamp to be in
nanoseconds. Without this data either isn't written properly.
3. Due to the restrictions on UDP buffer sizes we're writing metrics one
by one, instead of writing all of them at once.
Storing of application metrics in InfluxDB
This adds support for tracking metrics in InfluxDB, which in turn can be visualized using Grafana. For more information see #2936.
See merge request !2042
Douwe Maan
Dmitriy Zaporozhets
Robert Speicher
Douglas Barbosa Alexandre
Yorick Peterse
Stan Hu
Valery Sizov
Gabriel Mazetto
Michi302
Valery Sizov
Robert Speicher