gitlab-org--gitlab-foss/lib/gitlab/metrics/metric.rb
Yorick Peterse d345591fc8
Tracking of custom events
GitLab Performance Monitoring is now able to track custom events not
directly related to application performance. These events include the
number of tags pushed, repositories created, builds registered, etc.

The use of these events is to get a better overview of how a GitLab
instance is used and how that may affect performance. For example, a
large number of Git pushes may have a negative impact on the underlying
storage engine.

Events are stored in the "events" measurement and are not prefixed with
"rails_" or "sidekiq_", this makes it easier to query events with the
same name triggered from different parts of the application. All events
being stored in the same measurement also makes it easier to downsample
data.

Currently the following events are tracked:

* Creating repositories
* Removing repositories
* Changing the default branch of a repository
* Pushing a new tag
* Removing an existing tag
* Pushing a commit (along with the branch being pushed to)
* Pushing a new branch
* Removing an existing branch
* Importing a repository (along with the URL we're importing)
* Forking a repository (along with the source/target path)
* CI builds registered (and when no build could be found)
* CI builds being updated
* Rails and Sidekiq exceptions

Fixes gitlab-org/gitlab-ce#13720
2016-08-17 10:04:04 +02:00

52 lines
1.9 KiB
Ruby

module Gitlab
module Metrics
# Class for storing details of a single metric (label, value, etc).
class Metric
JITTER_RANGE = 0.000001..0.001
attr_reader :series, :values, :tags, :type
# series - The name of the series (as a String) to store the metric in.
# values - A Hash containing the values to store.
# tags - A Hash containing extra tags to add to the metrics.
def initialize(series, values, tags = {}, type = :metric)
@values = values
@series = series
@tags = tags
@type = type
end
def event?
type == :event
end
# Returns a Hash in a format that can be directly written to InfluxDB.
def to_hash
# InfluxDB overwrites an existing point if a new point has the same
# series, tag set, and timestamp. In a highly concurrent environment
# this means that using the number of seconds since the Unix epoch is
# inevitably going to collide with another timestamp. For example, two
# Rails requests processed by different processes may end up generating
# metrics using the _exact_ same timestamp (in seconds).
#
# Due to the way InfluxDB is set up there's no solution to this problem,
# all we can do is lower the amount of collisions. We do this by using
# System.real_time which returns the nanoseconds as a Float providing
# greater accuracy. We then add a small random value that is large
# enough to distinguish most timestamps but small enough to not alter
# the timestamp significantly.
#
# See https://gitlab.com/gitlab-com/operations/issues/175 for more
# information.
time = System.real_time(:nanosecond) + rand(JITTER_RANGE)
{
series: @series,
tags: @tags,
values: @values,
timestamp: time.to_i
}
end
end
end
end