Merge branch 'influxdb' into 'master'

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

2 files changed, 78 insertions, 0 deletions

diff --git a/config/gitlab.yml.example b/config/gitlab.yml.example
index 79fc7423b31..da6d4005da6 100644
--- a/config/gitlab.yml.example
+++ b/config/gitlab.yml.example
@@ -449,9 +449,26 @@ production: &base
       #
       # Ban an IP for one hour (3600s) after too many auth attempts
       # bantime: 3600
+  metrics:
+    host: localhost
+    enabled: false
+    # The name of the InfluxDB database to store metrics in.
+    database: gitlab
+    # Credentials to use for logging in to InfluxDB.
+    # username:
+    # password:
+    # The amount of InfluxDB connections to open.
+    # pool_size: 16
+    # The timeout of a connection in seconds.
+    # timeout: 10
+    # The minimum amount of milliseconds a method call has to take before it's
+    # tracked. Defaults to 10.
+    # method_call_threshold: 10
 
 development:
   <<: *base
+  metrics:
+    enabled: false
 
 test:
   <<: *base
@@ -494,6 +511,10 @@ test:
         user_filter: ''
         group_base: 'ou=groups,dc=example,dc=com'
         admin_group: ''
+  metrics:
+    enabled: false
 
 staging:
   <<: *base
+  metrics:
+    enabled: false
diff --git a/config/initializers/metrics.rb b/config/initializers/metrics.rb
new file mode 100644
index 00000000000..a47d2bf59a6
--- /dev/null
+++ b/config/initializers/metrics.rb
@@ -0,0 +1,57 @@
+if Gitlab::Metrics.enabled?
+  require 'influxdb'
+  require 'socket'
+  require 'connection_pool'
+  require 'method_source'
+
+  # These are manually require'd so the classes are registered properly with
+  # ActiveSupport.
+  require 'gitlab/metrics/subscribers/action_view'
+  require 'gitlab/metrics/subscribers/active_record'
+
+  Gitlab::Application.configure do |config|
+    config.middleware.use(Gitlab::Metrics::RackMiddleware)
+  end
+
+  Sidekiq.configure_server do |config|
+    config.server_middleware do |chain|
+      chain.add Gitlab::Metrics::SidekiqMiddleware
+    end
+  end
+
+  # This instruments all methods residing in app/models that (appear to) use any
+  # of the ActiveRecord methods. This has to take place _after_ initializing as
+  # for some unknown reason calling eager_load! earlier breaks Devise.
+  Gitlab::Application.config.after_initialize do
+    Rails.application.eager_load!
+
+    models = Rails.root.join('app', 'models').to_s
+
+    regex = Regexp.union(
+      ActiveRecord::Querying.public_instance_methods(false).map(&:to_s)
+    )
+
+    Gitlab::Metrics::Instrumentation.
+      instrument_class_hierarchy(ActiveRecord::Base) do |_, method|
+        loc = method.source_location
+
+        loc && loc[0].start_with?(models) && method.source =~ regex
+      end
+  end
+
+  Gitlab::Metrics::Instrumentation.configure do |config|
+    config.instrument_instance_methods(Gitlab::Shell)
+
+    config.instrument_methods(Gitlab::Git)
+
+    Gitlab::Git.constants.each do |name|
+      const = Gitlab::Git.const_get(name)
+
+      config.instrument_methods(const) if const.is_a?(Module)
+    end
+  end
+
+  GC::Profiler.enable
+
+  Gitlab::Metrics::Sampler.new.start
+end