From 23671600150cb022a09a77b8ea56a9465f19a013 Mon Sep 17 00:00:00 2001
From: Yorick Peterse <yorickpeterse@gmail.com>
Date: Wed, 13 Jan 2016 12:29:48 +0100
Subject: [PATCH 1/2] Make the metrics sampler interval configurable

---
 .../admin/application_settings_controller.rb  |   1 +
 .../application_settings/_form.html.haml      |   7 +
 ...60113111034_add_metrics_sample_interval.rb |   6 +
 db/schema.rb                                  | 504 +++++++++---------
 lib/gitlab/metrics.rb                         |   3 +-
 lib/gitlab/metrics/sampler.rb                 |   2 +-
 6 files changed, 270 insertions(+), 253 deletions(-)
 create mode 100644 db/migrate/20160113111034_add_metrics_sample_interval.rb

diff --git a/app/controllers/admin/application_settings_controller.rb b/app/controllers/admin/application_settings_controller.rb
index 44d06b6a647..91f7d78bd73 100644
--- a/app/controllers/admin/application_settings_controller.rb
+++ b/app/controllers/admin/application_settings_controller.rb
@@ -73,6 +73,7 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
       :metrics_pool_size,
       :metrics_timeout,
       :metrics_method_call_threshold,
+      :metrics_sample_interval,
       :recaptcha_enabled,
       :recaptcha_site_key,
       :recaptcha_private_key,
diff --git a/app/views/admin/application_settings/_form.html.haml b/app/views/admin/application_settings/_form.html.haml
index 81337432ab7..83f6814d822 100644
--- a/app/views/admin/application_settings/_form.html.haml
+++ b/app/views/admin/application_settings/_form.html.haml
@@ -202,6 +202,13 @@
         .help-block
           A method call is only tracked when it takes longer to complete than
           the given amount of milliseconds.
+    .form-group
+      = f.label :metrics_sample_interval, 'Sampler Interval (sec)', class: 'control-label col-sm-2'
+      .col-sm-10
+        = f.number_field :metrics_sample_interval, class: 'form-control'
+        .help-block
+          The sampling interval in seconds. Sampled data includes memory usage,
+          retained Ruby objects, file descriptors and so on.
 
   %fieldset
     %legend Spam and Anti-bot Protection
diff --git a/db/migrate/20160113111034_add_metrics_sample_interval.rb b/db/migrate/20160113111034_add_metrics_sample_interval.rb
new file mode 100644
index 00000000000..b741f5d2c75
--- /dev/null
+++ b/db/migrate/20160113111034_add_metrics_sample_interval.rb
@@ -0,0 +1,6 @@
+class AddMetricsSampleInterval < ActiveRecord::Migration
+  def change
+    add_column :application_settings, :metrics_sample_interval, :integer,
+      default: 15
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 2ded8a45e18..ecbe575bf83 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160106164438) do
+ActiveRecord::Schema.define(version: 20160113111034) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -32,23 +32,23 @@ ActiveRecord::Schema.define(version: 20160106164438) do
     t.text     "sign_in_text"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "home_page_url",                     limit: 255
-    t.integer  "default_branch_protection",                     default: 2
-    t.boolean  "twitter_sharing_enabled",                       default: true
+    t.string   "home_page_url"
+    t.integer  "default_branch_protection",         default: 2
+    t.boolean  "twitter_sharing_enabled",           default: true
     t.text     "restricted_visibility_levels"
-    t.boolean  "version_check_enabled",                         default: true
-    t.integer  "max_attachment_size",                           default: 10,          null: false
+    t.boolean  "version_check_enabled",             default: true
+    t.integer  "max_attachment_size",               default: 10,          null: false
     t.integer  "default_project_visibility"
     t.integer  "default_snippet_visibility"
     t.text     "restricted_signup_domains"
-    t.boolean  "user_oauth_applications",                       default: true
-    t.string   "after_sign_out_path",               limit: 255
-    t.integer  "session_expire_delay",                          default: 10080,       null: false
+    t.boolean  "user_oauth_applications",           default: true
+    t.string   "after_sign_out_path"
+    t.integer  "session_expire_delay",              default: 10080,       null: false
     t.text     "import_sources"
     t.text     "help_page_text"
-    t.string   "admin_notification_email",          limit: 255
-    t.boolean  "shared_runners_enabled",                        default: true,        null: false
-    t.integer  "max_artifacts_size",                            default: 100,         null: false
+    t.string   "admin_notification_email"
+    t.boolean  "shared_runners_enabled",            default: true,        null: false
+    t.integer  "max_artifacts_size",                default: 100,         null: false
     t.string   "runners_registration_token"
     t.boolean  "require_two_factor_authentication", default: false
     t.integer  "two_factor_grace_period",           default: 48
@@ -60,14 +60,15 @@ ActiveRecord::Schema.define(version: 20160106164438) do
     t.boolean  "recaptcha_enabled",                 default: false
     t.string   "recaptcha_site_key"
     t.string   "recaptcha_private_key"
-    t.integer  "metrics_port",                                  default: 8089
+    t.integer  "metrics_port",                      default: 8089
+    t.integer  "metrics_sample_interval",           default: 15
   end
 
   create_table "audit_events", force: :cascade do |t|
-    t.integer  "author_id",               null: false
-    t.string   "type",        limit: 255, null: false
-    t.integer  "entity_id",               null: false
-    t.string   "entity_type", limit: 255, null: false
+    t.integer  "author_id",   null: false
+    t.string   "type",        null: false
+    t.integer  "entity_id",   null: false
+    t.string   "entity_type", null: false
     t.text     "details"
     t.datetime "created_at"
     t.datetime "updated_at"
@@ -78,14 +79,14 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "audit_events", ["type"], name: "index_audit_events_on_type", using: :btree
 
   create_table "broadcast_messages", force: :cascade do |t|
-    t.text     "message",                null: false
+    t.text     "message",    null: false
     t.datetime "starts_at"
     t.datetime "ends_at"
     t.integer  "alert_type"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "color",      limit: 255
-    t.string   "font",       limit: 255
+    t.string   "color"
+    t.string   "font"
   end
 
   create_table "ci_application_settings", force: :cascade do |t|
@@ -97,7 +98,7 @@ ActiveRecord::Schema.define(version: 20160106164438) do
 
   create_table "ci_builds", force: :cascade do |t|
     t.integer  "project_id"
-    t.string   "status",             limit: 255
+    t.string   "status"
     t.datetime "finished_at"
     t.text     "trace"
     t.datetime "created_at"
@@ -108,19 +109,19 @@ ActiveRecord::Schema.define(version: 20160106164438) do
     t.integer  "commit_id"
     t.text     "commands"
     t.integer  "job_id"
-    t.string   "name",               limit: 255
-    t.boolean  "deploy",                         default: false
+    t.string   "name"
+    t.boolean  "deploy",             default: false
     t.text     "options"
-    t.boolean  "allow_failure",                  default: false, null: false
-    t.string   "stage",              limit: 255
+    t.boolean  "allow_failure",      default: false, null: false
+    t.string   "stage"
     t.integer  "trigger_request_id"
     t.integer  "stage_idx"
     t.boolean  "tag"
-    t.string   "ref",                limit: 255
+    t.string   "ref"
     t.integer  "user_id"
-    t.string   "type",               limit: 255
-    t.string   "target_url",         limit: 255
-    t.string   "description",        limit: 255
+    t.string   "type"
+    t.string   "target_url"
+    t.string   "description"
     t.text     "artifacts_file"
     t.integer  "gl_project_id"
   end
@@ -139,13 +140,13 @@ ActiveRecord::Schema.define(version: 20160106164438) do
 
   create_table "ci_commits", force: :cascade do |t|
     t.integer  "project_id"
-    t.string   "ref",           limit: 255
-    t.string   "sha",           limit: 255
-    t.string   "before_sha",    limit: 255
+    t.string   "ref"
+    t.string   "sha"
+    t.string   "before_sha"
     t.text     "push_data"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.boolean  "tag",                       default: false
+    t.boolean  "tag",           default: false
     t.text     "yaml_errors"
     t.datetime "committed_at"
     t.integer  "gl_project_id"
@@ -172,16 +173,16 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "ci_events", ["project_id"], name: "index_ci_events_on_project_id", using: :btree
 
   create_table "ci_jobs", force: :cascade do |t|
-    t.integer  "project_id",                                      null: false
+    t.integer  "project_id",                          null: false
     t.text     "commands"
-    t.boolean  "active",                     default: true,       null: false
+    t.boolean  "active",         default: true,       null: false
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "name",           limit: 255
-    t.boolean  "build_branches",             default: true,       null: false
-    t.boolean  "build_tags",                 default: false,      null: false
-    t.string   "job_type",       limit: 255, default: "parallel"
-    t.string   "refs",           limit: 255
+    t.string   "name"
+    t.boolean  "build_branches", default: true,       null: false
+    t.boolean  "build_tags",     default: false,      null: false
+    t.string   "job_type",       default: "parallel"
+    t.string   "refs"
     t.datetime "deleted_at"
   end
 
@@ -189,25 +190,25 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "ci_jobs", ["project_id"], name: "index_ci_jobs_on_project_id", using: :btree
 
   create_table "ci_projects", force: :cascade do |t|
-    t.string   "name",                     limit: 255
-    t.integer  "timeout",                              default: 3600,  null: false
+    t.string   "name"
+    t.integer  "timeout",                  default: 3600,  null: false
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "token",                    limit: 255
-    t.string   "default_ref",              limit: 255
-    t.string   "path",                     limit: 255
-    t.boolean  "always_build",                         default: false, null: false
+    t.string   "token"
+    t.string   "default_ref"
+    t.string   "path"
+    t.boolean  "always_build",             default: false, null: false
     t.integer  "polling_interval"
-    t.boolean  "public",                               default: false, null: false
-    t.string   "ssh_url_to_repo",          limit: 255
+    t.boolean  "public",                   default: false, null: false
+    t.string   "ssh_url_to_repo"
     t.integer  "gitlab_id"
-    t.boolean  "allow_git_fetch",                      default: true,  null: false
-    t.string   "email_recipients",         limit: 255, default: "",    null: false
-    t.boolean  "email_add_pusher",                     default: true,  null: false
-    t.boolean  "email_only_broken_builds",             default: true,  null: false
-    t.string   "skip_refs",                limit: 255
-    t.string   "coverage_regex",           limit: 255
-    t.boolean  "shared_runners_enabled",               default: false
+    t.boolean  "allow_git_fetch",          default: true,  null: false
+    t.string   "email_recipients",         default: "",    null: false
+    t.boolean  "email_add_pusher",         default: true,  null: false
+    t.boolean  "email_only_broken_builds", default: true,  null: false
+    t.string   "skip_refs"
+    t.string   "coverage_regex"
+    t.boolean  "shared_runners_enabled",   default: false
     t.text     "generated_yaml_config"
   end
 
@@ -226,34 +227,34 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "ci_runner_projects", ["runner_id"], name: "index_ci_runner_projects_on_runner_id", using: :btree
 
   create_table "ci_runners", force: :cascade do |t|
-    t.string   "token",        limit: 255
+    t.string   "token"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "description",  limit: 255
+    t.string   "description"
     t.datetime "contacted_at"
-    t.boolean  "active",                   default: true,  null: false
-    t.boolean  "is_shared",                default: false
-    t.string   "name",         limit: 255
-    t.string   "version",      limit: 255
-    t.string   "revision",     limit: 255
-    t.string   "platform",     limit: 255
-    t.string   "architecture", limit: 255
+    t.boolean  "active",       default: true,  null: false
+    t.boolean  "is_shared",    default: false
+    t.string   "name"
+    t.string   "version"
+    t.string   "revision"
+    t.string   "platform"
+    t.string   "architecture"
   end
 
   create_table "ci_services", force: :cascade do |t|
-    t.string   "type",       limit: 255
-    t.string   "title",      limit: 255
-    t.integer  "project_id",                             null: false
+    t.string   "type"
+    t.string   "title"
+    t.integer  "project_id",                 null: false
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.boolean  "active",                 default: false, null: false
+    t.boolean  "active",     default: false, null: false
     t.text     "properties"
   end
 
   add_index "ci_services", ["project_id"], name: "index_ci_services_on_project_id", using: :btree
 
   create_table "ci_sessions", force: :cascade do |t|
-    t.string   "session_id", limit: 255, null: false
+    t.string   "session_id", null: false
     t.text     "data"
     t.datetime "created_at"
     t.datetime "updated_at"
@@ -265,9 +266,9 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   create_table "ci_taggings", force: :cascade do |t|
     t.integer  "tag_id"
     t.integer  "taggable_id"
-    t.string   "taggable_type", limit: 255
+    t.string   "taggable_type"
     t.integer  "tagger_id"
-    t.string   "tagger_type",   limit: 255
+    t.string   "tagger_type"
     t.string   "context",       limit: 128
     t.datetime "created_at"
   end
@@ -276,8 +277,8 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "ci_taggings", ["taggable_id", "taggable_type", "context"], name: "index_ci_taggings_on_taggable_id_and_taggable_type_and_context", using: :btree
 
   create_table "ci_tags", force: :cascade do |t|
-    t.string  "name",           limit: 255
-    t.integer "taggings_count",             default: 0
+    t.string  "name"
+    t.integer "taggings_count", default: 0
   end
 
   add_index "ci_tags", ["name"], name: "index_ci_tags_on_name", unique: true, using: :btree
@@ -291,7 +292,7 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   end
 
   create_table "ci_triggers", force: :cascade do |t|
-    t.string   "token",         limit: 255
+    t.string   "token"
     t.integer  "project_id"
     t.datetime "deleted_at"
     t.datetime "created_at"
@@ -304,19 +305,19 @@ ActiveRecord::Schema.define(version: 20160106164438) do
 
   create_table "ci_variables", force: :cascade do |t|
     t.integer "project_id"
-    t.string  "key",                  limit: 255
+    t.string  "key"
     t.text    "value"
     t.text    "encrypted_value"
-    t.string  "encrypted_value_salt", limit: 255
-    t.string  "encrypted_value_iv",   limit: 255
+    t.string  "encrypted_value_salt"
+    t.string  "encrypted_value_iv"
     t.integer "gl_project_id"
   end
 
   add_index "ci_variables", ["gl_project_id"], name: "index_ci_variables_on_gl_project_id", using: :btree
 
   create_table "ci_web_hooks", force: :cascade do |t|
-    t.string   "url",        limit: 255, null: false
-    t.integer  "project_id",             null: false
+    t.string   "url",        null: false
+    t.integer  "project_id", null: false
     t.datetime "created_at"
     t.datetime "updated_at"
   end
@@ -331,8 +332,8 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "deploy_keys_projects", ["project_id"], name: "index_deploy_keys_projects_on_project_id", using: :btree
 
   create_table "emails", force: :cascade do |t|
-    t.integer  "user_id",                null: false
-    t.string   "email",      limit: 255, null: false
+    t.integer  "user_id",    null: false
+    t.string   "email",      null: false
     t.datetime "created_at"
     t.datetime "updated_at"
   end
@@ -341,9 +342,9 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "emails", ["user_id"], name: "index_emails_on_user_id", using: :btree
 
   create_table "events", force: :cascade do |t|
-    t.string   "target_type", limit: 255
+    t.string   "target_type"
     t.integer  "target_id"
-    t.string   "title",       limit: 255
+    t.string   "title"
     t.text     "data"
     t.integer  "project_id"
     t.datetime "created_at"
@@ -369,8 +370,8 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "forked_project_links", ["forked_to_project_id"], name: "index_forked_project_links_on_forked_to_project_id", unique: true, using: :btree
 
   create_table "identities", force: :cascade do |t|
-    t.string   "extern_uid", limit: 255
-    t.string   "provider",   limit: 255
+    t.string   "extern_uid"
+    t.string   "provider"
     t.integer  "user_id"
     t.datetime "created_at"
     t.datetime "updated_at"
@@ -380,17 +381,17 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "identities", ["user_id"], name: "index_identities_on_user_id", using: :btree
 
   create_table "issues", force: :cascade do |t|
-    t.string   "title",         limit: 255
+    t.string   "title"
     t.integer  "assignee_id"
     t.integer  "author_id"
     t.integer  "project_id"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.integer  "position",                  default: 0
-    t.string   "branch_name",   limit: 255
+    t.integer  "position",      default: 0
+    t.string   "branch_name"
     t.text     "description"
     t.integer  "milestone_id"
-    t.string   "state",         limit: 255
+    t.string   "state"
     t.integer  "iid"
     t.integer  "updated_by_id"
   end
@@ -410,10 +411,10 @@ ActiveRecord::Schema.define(version: 20160106164438) do
     t.datetime "created_at"
     t.datetime "updated_at"
     t.text     "key"
-    t.string   "title",       limit: 255
-    t.string   "type",        limit: 255
-    t.string   "fingerprint", limit: 255
-    t.boolean  "public",                  default: false, null: false
+    t.string   "title"
+    t.string   "type"
+    t.string   "fingerprint"
+    t.boolean  "public",      default: false, null: false
   end
 
   add_index "keys", ["created_at", "id"], name: "index_keys_on_created_at_and_id", using: :btree
@@ -422,7 +423,7 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   create_table "label_links", force: :cascade do |t|
     t.integer  "label_id"
     t.integer  "target_id"
-    t.string   "target_type", limit: 255
+    t.string   "target_type"
     t.datetime "created_at"
     t.datetime "updated_at"
   end
@@ -431,22 +432,22 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "label_links", ["target_id", "target_type"], name: "index_label_links_on_target_id_and_target_type", using: :btree
 
   create_table "labels", force: :cascade do |t|
-    t.string   "title",      limit: 255
-    t.string   "color",      limit: 255
+    t.string   "title"
+    t.string   "color"
     t.integer  "project_id"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.boolean  "template",               default: false
+    t.boolean  "template",   default: false
   end
 
   add_index "labels", ["project_id"], name: "index_labels_on_project_id", using: :btree
 
   create_table "lfs_objects", force: :cascade do |t|
-    t.string   "oid",        limit: 255, null: false
-    t.integer  "size",                   null: false
+    t.string   "oid",        null: false
+    t.integer  "size",       null: false
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "file",       limit: 255
+    t.string   "file"
   end
 
   add_index "lfs_objects", ["oid"], name: "index_lfs_objects_on_oid", unique: true, using: :btree
@@ -461,17 +462,17 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "lfs_objects_projects", ["project_id"], name: "index_lfs_objects_projects_on_project_id", using: :btree
 
   create_table "members", force: :cascade do |t|
-    t.integer  "access_level",                   null: false
-    t.integer  "source_id",                      null: false
-    t.string   "source_type",        limit: 255, null: false
+    t.integer  "access_level",       null: false
+    t.integer  "source_id",          null: false
+    t.string   "source_type",        null: false
     t.integer  "user_id"
-    t.integer  "notification_level",             null: false
-    t.string   "type",               limit: 255
+    t.integer  "notification_level", null: false
+    t.string   "type"
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "created_by_id"
-    t.string   "invite_email",       limit: 255
-    t.string   "invite_token",       limit: 255
+    t.string   "invite_email"
+    t.string   "invite_token"
     t.datetime "invite_accepted_at"
   end
 
@@ -483,10 +484,10 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "members", ["user_id"], name: "index_members_on_user_id", using: :btree
 
   create_table "merge_request_diffs", force: :cascade do |t|
-    t.string   "state",            limit: 255
+    t.string   "state"
     t.text     "st_commits"
     t.text     "st_diffs"
-    t.integer  "merge_request_id",             null: false
+    t.integer  "merge_request_id", null: false
     t.datetime "created_at"
     t.datetime "updated_at"
   end
@@ -494,26 +495,26 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "merge_request_diffs", ["merge_request_id"], name: "index_merge_request_diffs_on_merge_request_id", unique: true, using: :btree
 
   create_table "merge_requests", force: :cascade do |t|
-    t.string   "target_branch",             limit: 255,                 null: false
-    t.string   "source_branch",             limit: 255,                 null: false
-    t.integer  "source_project_id",                                     null: false
+    t.string   "target_branch",                             null: false
+    t.string   "source_branch",                             null: false
+    t.integer  "source_project_id",                         null: false
     t.integer  "author_id"
     t.integer  "assignee_id"
-    t.string   "title",                     limit: 255
+    t.string   "title"
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "milestone_id"
-    t.string   "state",                     limit: 255
-    t.string   "merge_status",              limit: 255
-    t.integer  "target_project_id",                                     null: false
+    t.string   "state"
+    t.string   "merge_status"
+    t.integer  "target_project_id",                         null: false
     t.integer  "iid"
     t.text     "description"
-    t.integer  "position",                              default: 0
+    t.integer  "position",                  default: 0
     t.datetime "locked_at"
     t.integer  "updated_by_id"
-    t.string   "merge_error",               limit: 255
+    t.string   "merge_error"
     t.text     "merge_params"
-    t.boolean  "merge_when_build_succeeds",             default: false, null: false
+    t.boolean  "merge_when_build_succeeds", default: false, null: false
     t.integer  "merge_user_id"
   end
 
@@ -529,13 +530,13 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "merge_requests", ["title"], name: "index_merge_requests_on_title", using: :btree
 
   create_table "milestones", force: :cascade do |t|
-    t.string   "title",       limit: 255, null: false
-    t.integer  "project_id",              null: false
+    t.string   "title",       null: false
+    t.integer  "project_id",  null: false
     t.text     "description"
     t.date     "due_date"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "state",       limit: 255
+    t.string   "state"
     t.integer  "iid"
   end
 
@@ -543,16 +544,17 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "milestones", ["due_date"], name: "index_milestones_on_due_date", using: :btree
   add_index "milestones", ["project_id", "iid"], name: "index_milestones_on_project_id_and_iid", unique: true, using: :btree
   add_index "milestones", ["project_id"], name: "index_milestones_on_project_id", using: :btree
+  add_index "milestones", ["title"], name: "index_milestones_on_title", using: :btree
 
   create_table "namespaces", force: :cascade do |t|
-    t.string   "name",        limit: 255,              null: false
-    t.string   "path",        limit: 255,              null: false
+    t.string   "name",                     null: false
+    t.string   "path",                     null: false
     t.integer  "owner_id"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "type",        limit: 255
-    t.string   "description", limit: 255, default: "", null: false
-    t.string   "avatar",      limit: 255
+    t.string   "type"
+    t.string   "description", default: "", null: false
+    t.string   "avatar"
   end
 
   add_index "namespaces", ["created_at", "id"], name: "index_namespaces_on_created_at_and_id", using: :btree
@@ -563,19 +565,19 @@ ActiveRecord::Schema.define(version: 20160106164438) do
 
   create_table "notes", force: :cascade do |t|
     t.text     "note"
-    t.string   "noteable_type", limit: 255
+    t.string   "noteable_type"
     t.integer  "author_id"
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "project_id"
-    t.string   "attachment",    limit: 255
-    t.string   "line_code",     limit: 255
-    t.string   "commit_id",     limit: 255
+    t.string   "attachment"
+    t.string   "line_code"
+    t.string   "commit_id"
     t.integer  "noteable_id"
-    t.boolean  "system",                    default: false, null: false
+    t.boolean  "system",        default: false, null: false
     t.text     "st_diff"
     t.integer  "updated_by_id"
-    t.boolean  "is_award",                  default: false, null: false
+    t.boolean  "is_award",      default: false, null: false
   end
 
   add_index "notes", ["author_id"], name: "index_notes_on_author_id", using: :btree
@@ -591,14 +593,14 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "notes", ["updated_at"], name: "index_notes_on_updated_at", using: :btree
 
   create_table "oauth_access_grants", force: :cascade do |t|
-    t.integer  "resource_owner_id",             null: false
-    t.integer  "application_id",                null: false
-    t.string   "token",             limit: 255, null: false
-    t.integer  "expires_in",                    null: false
-    t.text     "redirect_uri",                  null: false
-    t.datetime "created_at",                    null: false
+    t.integer  "resource_owner_id", null: false
+    t.integer  "application_id",    null: false
+    t.string   "token",             null: false
+    t.integer  "expires_in",        null: false
+    t.text     "redirect_uri",      null: false
+    t.datetime "created_at",        null: false
     t.datetime "revoked_at"
-    t.string   "scopes",            limit: 255
+    t.string   "scopes"
   end
 
   add_index "oauth_access_grants", ["token"], name: "index_oauth_access_grants_on_token", unique: true, using: :btree
@@ -606,12 +608,12 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   create_table "oauth_access_tokens", force: :cascade do |t|
     t.integer  "resource_owner_id"
     t.integer  "application_id"
-    t.string   "token",             limit: 255, null: false
-    t.string   "refresh_token",     limit: 255
+    t.string   "token",             null: false
+    t.string   "refresh_token"
     t.integer  "expires_in"
     t.datetime "revoked_at"
-    t.datetime "created_at",                    null: false
-    t.string   "scopes",            limit: 255
+    t.datetime "created_at",        null: false
+    t.string   "scopes"
   end
 
   add_index "oauth_access_tokens", ["refresh_token"], name: "index_oauth_access_tokens_on_refresh_token", unique: true, using: :btree
@@ -619,15 +621,15 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "oauth_access_tokens", ["token"], name: "index_oauth_access_tokens_on_token", unique: true, using: :btree
 
   create_table "oauth_applications", force: :cascade do |t|
-    t.string   "name",         limit: 255,              null: false
-    t.string   "uid",          limit: 255,              null: false
-    t.string   "secret",       limit: 255,              null: false
-    t.text     "redirect_uri",                          null: false
-    t.string   "scopes",       limit: 255, default: "", null: false
+    t.string   "name",                      null: false
+    t.string   "uid",                       null: false
+    t.string   "secret",                    null: false
+    t.text     "redirect_uri",              null: false
+    t.string   "scopes",       default: "", null: false
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "owner_id"
-    t.string   "owner_type",   limit: 255
+    t.string   "owner_type"
   end
 
   add_index "oauth_applications", ["owner_id", "owner_type"], name: "index_oauth_applications_on_owner_id_and_owner_type", using: :btree
@@ -639,39 +641,39 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   end
 
   create_table "projects", force: :cascade do |t|
-    t.string   "name",                   limit: 255
-    t.string   "path",                   limit: 255
+    t.string   "name"
+    t.string   "path"
     t.text     "description"
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "creator_id"
-    t.boolean  "issues_enabled",                     default: true,     null: false
-    t.boolean  "wall_enabled",                       default: true,     null: false
-    t.boolean  "merge_requests_enabled",             default: true,     null: false
-    t.boolean  "wiki_enabled",                       default: true,     null: false
+    t.boolean  "issues_enabled",         default: true,     null: false
+    t.boolean  "wall_enabled",           default: true,     null: false
+    t.boolean  "merge_requests_enabled", default: true,     null: false
+    t.boolean  "wiki_enabled",           default: true,     null: false
     t.integer  "namespace_id"
-    t.string   "issues_tracker",         limit: 255, default: "gitlab", null: false
-    t.string   "issues_tracker_id",      limit: 255
-    t.boolean  "snippets_enabled",                   default: true,     null: false
+    t.string   "issues_tracker",         default: "gitlab", null: false
+    t.string   "issues_tracker_id"
+    t.boolean  "snippets_enabled",       default: true,     null: false
     t.datetime "last_activity_at"
-    t.string   "import_url",             limit: 255
-    t.integer  "visibility_level",                   default: 0,        null: false
-    t.boolean  "archived",                           default: false,    null: false
-    t.string   "avatar",                 limit: 255
-    t.string   "import_status",          limit: 255
-    t.float    "repository_size",                    default: 0.0
-    t.integer  "star_count",                         default: 0,        null: false
-    t.string   "import_type",            limit: 255
-    t.string   "import_source",          limit: 255
-    t.integer  "commit_count",                       default: 0
+    t.string   "import_url"
+    t.integer  "visibility_level",       default: 0,        null: false
+    t.boolean  "archived",               default: false,    null: false
+    t.string   "avatar"
+    t.string   "import_status"
+    t.float    "repository_size",        default: 0.0
+    t.integer  "star_count",             default: 0,        null: false
+    t.string   "import_type"
+    t.string   "import_source"
+    t.integer  "commit_count",           default: 0
     t.text     "import_error"
     t.integer  "ci_id"
-    t.boolean  "builds_enabled",                     default: true,     null: false
-    t.boolean  "shared_runners_enabled",             default: true,     null: false
+    t.boolean  "builds_enabled",         default: true,     null: false
+    t.boolean  "shared_runners_enabled", default: true,     null: false
     t.string   "runners_token"
     t.string   "build_coverage_regex"
-    t.boolean  "build_allow_git_fetch",              default: true,     null: false
-    t.integer  "build_timeout",                      default: 3600,     null: false
+    t.boolean  "build_allow_git_fetch",  default: true,     null: false
+    t.integer  "build_timeout",          default: 3600,     null: false
   end
 
   add_index "projects", ["builds_enabled", "shared_runners_enabled"], name: "index_projects_on_builds_enabled_and_shared_runners_enabled", using: :btree
@@ -687,17 +689,17 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "projects", ["visibility_level"], name: "index_projects_on_visibility_level", using: :btree
 
   create_table "protected_branches", force: :cascade do |t|
-    t.integer  "project_id",                                      null: false
-    t.string   "name",                limit: 255,                 null: false
+    t.integer  "project_id",                          null: false
+    t.string   "name",                                null: false
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.boolean  "developers_can_push",             default: false, null: false
+    t.boolean  "developers_can_push", default: false, null: false
   end
 
   add_index "protected_branches", ["project_id"], name: "index_protected_branches_on_project_id", using: :btree
 
   create_table "releases", force: :cascade do |t|
-    t.string   "tag",         limit: 255
+    t.string   "tag"
     t.text     "description"
     t.integer  "project_id"
     t.datetime "created_at"
@@ -710,30 +712,30 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   create_table "sent_notifications", force: :cascade do |t|
     t.integer "project_id"
     t.integer "noteable_id"
-    t.string  "noteable_type", limit: 255
+    t.string  "noteable_type"
     t.integer "recipient_id"
-    t.string  "commit_id",     limit: 255
-    t.string  "reply_key",     limit: 255, null: false
-    t.string  "line_code",     limit: 255
+    t.string  "commit_id"
+    t.string  "reply_key",     null: false
+    t.string  "line_code"
   end
 
   add_index "sent_notifications", ["reply_key"], name: "index_sent_notifications_on_reply_key", unique: true, using: :btree
 
   create_table "services", force: :cascade do |t|
-    t.string   "type",                  limit: 255
-    t.string   "title",                 limit: 255
+    t.string   "type"
+    t.string   "title"
     t.integer  "project_id"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.boolean  "active",                            default: false, null: false
+    t.boolean  "active",                default: false, null: false
     t.text     "properties"
-    t.boolean  "template",                          default: false
-    t.boolean  "push_events",                       default: true
-    t.boolean  "issues_events",                     default: true
-    t.boolean  "merge_requests_events",             default: true
-    t.boolean  "tag_push_events",                   default: true
-    t.boolean  "note_events",                       default: true,  null: false
-    t.boolean  "build_events",                      default: false, null: false
+    t.boolean  "template",              default: false
+    t.boolean  "push_events",           default: true
+    t.boolean  "issues_events",         default: true
+    t.boolean  "merge_requests_events", default: true
+    t.boolean  "tag_push_events",       default: true
+    t.boolean  "note_events",           default: true,  null: false
+    t.boolean  "build_events",          default: false, null: false
   end
 
   add_index "services", ["created_at", "id"], name: "index_services_on_created_at_and_id", using: :btree
@@ -741,16 +743,16 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "services", ["template"], name: "index_services_on_template", using: :btree
 
   create_table "snippets", force: :cascade do |t|
-    t.string   "title",            limit: 255
+    t.string   "title"
     t.text     "content"
-    t.integer  "author_id",                                null: false
+    t.integer  "author_id",                    null: false
     t.integer  "project_id"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "file_name",        limit: 255
+    t.string   "file_name"
     t.datetime "expires_at"
-    t.string   "type",             limit: 255
-    t.integer  "visibility_level",             default: 0, null: false
+    t.string   "type"
+    t.integer  "visibility_level", default: 0, null: false
   end
 
   add_index "snippets", ["author_id"], name: "index_snippets_on_author_id", using: :btree
@@ -763,7 +765,7 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   create_table "subscriptions", force: :cascade do |t|
     t.integer  "user_id"
     t.integer  "subscribable_id"
-    t.string   "subscribable_type", limit: 255
+    t.string   "subscribable_type"
     t.boolean  "subscribed"
     t.datetime "created_at"
     t.datetime "updated_at"
@@ -774,10 +776,10 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   create_table "taggings", force: :cascade do |t|
     t.integer  "tag_id"
     t.integer  "taggable_id"
-    t.string   "taggable_type", limit: 255
+    t.string   "taggable_type"
     t.integer  "tagger_id"
-    t.string   "tagger_type",   limit: 255
-    t.string   "context",       limit: 255
+    t.string   "tagger_type"
+    t.string   "context"
     t.datetime "created_at"
   end
 
@@ -785,67 +787,67 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "taggings", ["taggable_id", "taggable_type", "context"], name: "index_taggings_on_taggable_id_and_taggable_type_and_context", using: :btree
 
   create_table "tags", force: :cascade do |t|
-    t.string  "name",           limit: 255
-    t.integer "taggings_count",             default: 0
+    t.string  "name"
+    t.integer "taggings_count", default: 0
   end
 
   add_index "tags", ["name"], name: "index_tags_on_name", unique: true, using: :btree
 
   create_table "users", force: :cascade do |t|
-    t.string   "email",                       limit: 255, default: "",    null: false
-    t.string   "encrypted_password",          limit: 255, default: "",    null: false
-    t.string   "reset_password_token",        limit: 255
+    t.string   "email",                       default: "",    null: false
+    t.string   "encrypted_password",          default: "",    null: false
+    t.string   "reset_password_token"
     t.datetime "reset_password_sent_at"
     t.datetime "remember_created_at"
-    t.integer  "sign_in_count",                           default: 0
+    t.integer  "sign_in_count",               default: 0
     t.datetime "current_sign_in_at"
     t.datetime "last_sign_in_at"
-    t.string   "current_sign_in_ip",          limit: 255
-    t.string   "last_sign_in_ip",             limit: 255
+    t.string   "current_sign_in_ip"
+    t.string   "last_sign_in_ip"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "name",                        limit: 255
-    t.boolean  "admin",                                   default: false, null: false
-    t.integer  "projects_limit",                          default: 10
-    t.string   "skype",                       limit: 255, default: "",    null: false
-    t.string   "linkedin",                    limit: 255, default: "",    null: false
-    t.string   "twitter",                     limit: 255, default: "",    null: false
-    t.string   "authentication_token",        limit: 255
-    t.integer  "theme_id",                                default: 1,     null: false
-    t.string   "bio",                         limit: 255
-    t.integer  "failed_attempts",                         default: 0
+    t.string   "name"
+    t.boolean  "admin",                       default: false, null: false
+    t.integer  "projects_limit",              default: 10
+    t.string   "skype",                       default: "",    null: false
+    t.string   "linkedin",                    default: "",    null: false
+    t.string   "twitter",                     default: "",    null: false
+    t.string   "authentication_token"
+    t.integer  "theme_id",                    default: 1,     null: false
+    t.string   "bio"
+    t.integer  "failed_attempts",             default: 0
     t.datetime "locked_at"
-    t.string   "username",                    limit: 255
-    t.boolean  "can_create_group",                        default: true,  null: false
-    t.boolean  "can_create_team",                         default: true,  null: false
-    t.string   "state",                       limit: 255
-    t.integer  "color_scheme_id",                         default: 1,     null: false
-    t.integer  "notification_level",                      default: 1,     null: false
+    t.string   "username"
+    t.boolean  "can_create_group",            default: true,  null: false
+    t.boolean  "can_create_team",             default: true,  null: false
+    t.string   "state"
+    t.integer  "color_scheme_id",             default: 1,     null: false
+    t.integer  "notification_level",          default: 1,     null: false
     t.datetime "password_expires_at"
     t.integer  "created_by_id"
     t.datetime "last_credential_check_at"
-    t.string   "avatar",                      limit: 255
-    t.string   "confirmation_token",          limit: 255
+    t.string   "avatar"
+    t.string   "confirmation_token"
     t.datetime "confirmed_at"
     t.datetime "confirmation_sent_at"
-    t.string   "unconfirmed_email",           limit: 255
-    t.boolean  "hide_no_ssh_key",                         default: false
-    t.string   "website_url",                 limit: 255, default: "",    null: false
-    t.string   "notification_email",          limit: 255
-    t.boolean  "hide_no_password",                        default: false
-    t.boolean  "password_automatically_set",              default: false
-    t.string   "location",                    limit: 255
-    t.string   "encrypted_otp_secret",        limit: 255
-    t.string   "encrypted_otp_secret_iv",     limit: 255
-    t.string   "encrypted_otp_secret_salt",   limit: 255
-    t.boolean  "otp_required_for_login",                  default: false, null: false
+    t.string   "unconfirmed_email"
+    t.boolean  "hide_no_ssh_key",             default: false
+    t.string   "website_url",                 default: "",    null: false
+    t.string   "notification_email"
+    t.boolean  "hide_no_password",            default: false
+    t.boolean  "password_automatically_set",  default: false
+    t.string   "location"
+    t.string   "encrypted_otp_secret"
+    t.string   "encrypted_otp_secret_iv"
+    t.string   "encrypted_otp_secret_salt"
+    t.boolean  "otp_required_for_login",      default: false, null: false
     t.text     "otp_backup_codes"
-    t.string   "public_email",                limit: 255, default: "",    null: false
-    t.integer  "dashboard",                               default: 0
-    t.integer  "project_view",                            default: 0
+    t.string   "public_email",                default: "",    null: false
+    t.integer  "dashboard",                   default: 0
+    t.integer  "project_view",                default: 0
     t.integer  "consumed_timestep"
-    t.integer  "layout",                                  default: 0
-    t.boolean  "hide_project_limit",                      default: false
+    t.integer  "layout",                      default: 0
+    t.boolean  "hide_project_limit",          default: false
     t.string   "unlock_token"
     t.datetime "otp_grace_period_started_at"
   end
@@ -872,19 +874,19 @@ ActiveRecord::Schema.define(version: 20160106164438) do
   add_index "users_star_projects", ["user_id"], name: "index_users_star_projects_on_user_id", using: :btree
 
   create_table "web_hooks", force: :cascade do |t|
-    t.string   "url",                     limit: 255
+    t.string   "url"
     t.integer  "project_id"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "type",                    limit: 255, default: "ProjectHook"
+    t.string   "type",                    default: "ProjectHook"
     t.integer  "service_id"
-    t.boolean  "push_events",                         default: true,          null: false
-    t.boolean  "issues_events",                       default: false,         null: false
-    t.boolean  "merge_requests_events",               default: false,         null: false
-    t.boolean  "tag_push_events",                     default: false
-    t.boolean  "note_events",                         default: false,         null: false
-    t.boolean  "enable_ssl_verification",             default: true
-    t.boolean  "build_events",                        default: false,         null: false
+    t.boolean  "push_events",             default: true,          null: false
+    t.boolean  "issues_events",           default: false,         null: false
+    t.boolean  "merge_requests_events",   default: false,         null: false
+    t.boolean  "tag_push_events",         default: false
+    t.boolean  "note_events",             default: false,         null: false
+    t.boolean  "enable_ssl_verification", default: true
+    t.boolean  "build_events",            default: false,         null: false
   end
 
   add_index "web_hooks", ["created_at", "id"], name: "index_web_hooks_on_created_at_and_id", using: :btree
diff --git a/lib/gitlab/metrics.rb b/lib/gitlab/metrics.rb
index cdf7c168ff2..88a265c6af2 100644
--- a/lib/gitlab/metrics.rb
+++ b/lib/gitlab/metrics.rb
@@ -13,7 +13,8 @@ module Gitlab
         timeout:               current_application_settings[:metrics_timeout],
         method_call_threshold: current_application_settings[:metrics_method_call_threshold],
         host:                  current_application_settings[:metrics_host],
-        port:                  current_application_settings[:metrics_port]
+        port:                  current_application_settings[:metrics_port],
+        sample_interval:       current_application_settings[:metrics_sample_interval] || 15
       }
     end
 
diff --git a/lib/gitlab/metrics/sampler.rb b/lib/gitlab/metrics/sampler.rb
index 1ea425bc904..c2913841de3 100644
--- a/lib/gitlab/metrics/sampler.rb
+++ b/lib/gitlab/metrics/sampler.rb
@@ -7,7 +7,7 @@ module Gitlab
     # statistics, etc.
     class Sampler
       # interval - The sampling interval in seconds.
-      def initialize(interval = 15)
+      def initialize(interval = Metrics.settings[:sample_interval])
         @interval = interval
         @metrics  = []
 

From 057eb824b5d7f38547506303dc80da6164715420 Mon Sep 17 00:00:00 2001
From: Yorick Peterse <yorickpeterse@gmail.com>
Date: Wed, 13 Jan 2016 12:57:46 +0100
Subject: [PATCH 2/2] Randomize metrics sample intervals

Sampling data at a fixed interval means we can potentially miss data
from events occurring between sampling intervals. For example, say we
sample data every 15 seconds but Unicorn workers get killed after 10
seconds. In this particular case it's possible to miss interesting data
as the sampler will never get to actually submitting data.

To work around this (at least for the most part) the sampling interval
is randomized as following:

1. Take the user specified sampling interval (15 seconds by default)
2. Divide it by 2 (referred to as "half" below)
3. Generate a range (using a step of 0.1) from -"half" to "half"
4. Every time the sampler goes to sleep we'll grab the user provided
   interval and add a randomly chosen "adjustment" to it while making
   sure we don't pick the same value twice in a row.

For a specified timeout of 15 this means the actual intervals can be
anywhere between 7.5 and 22.5, but never can the same interval be used
twice in a row.

The rationale behind this change is that on dev.gitlab.org I'm sometimes
seeing certain Gitlab::Git/Rugged objects being retained, but only for a
few minutes every 24 hours. Knowing the code of Gitlab and how much
memory it uses/leaks I suspect we're missing data due to workers getting
terminated before the sampler can write its data to InfluxDB.
---
 lib/gitlab/metrics/sampler.rb           | 28 ++++++++++++++++++++++---
 spec/lib/gitlab/metrics/sampler_spec.rb | 22 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/lib/gitlab/metrics/sampler.rb b/lib/gitlab/metrics/sampler.rb
index c2913841de3..fc709222a9b 100644
--- a/lib/gitlab/metrics/sampler.rb
+++ b/lib/gitlab/metrics/sampler.rb
@@ -8,8 +8,13 @@ module Gitlab
     class Sampler
       # interval - The sampling interval in seconds.
       def initialize(interval = Metrics.settings[:sample_interval])
-        @interval = interval
-        @metrics  = []
+        interval_half = interval.to_f / 2
+
+        @interval       = interval
+        @interval_steps = (-interval_half..interval_half).step(0.1).to_a
+        @last_step      = nil
+
+        @metrics = []
 
         @last_minor_gc = Delta.new(GC.stat[:minor_gc_count])
         @last_major_gc = Delta.new(GC.stat[:major_gc_count])
@@ -26,7 +31,7 @@ module Gitlab
           Thread.current.abort_on_exception = true
 
           loop do
-            sleep(@interval)
+            sleep(sleep_interval)
 
             sample
           end
@@ -102,6 +107,23 @@ module Gitlab
       def sidekiq?
         Sidekiq.server?
       end
+
+      # Returns the sleep interval with a random adjustment.
+      #
+      # The random adjustment is put in place to ensure we:
+      #
+      # 1. Don't generate samples at the exact same interval every time (thus
+      #    potentially missing anything that happens in between samples).
+      # 2. Don't sample data at the same interval two times in a row.
+      def sleep_interval
+        while step = @interval_steps.sample
+          if step != @last_step
+            @last_step = step
+
+            return @interval + @last_step
+          end
+        end
+      end
     end
   end
 end
diff --git a/spec/lib/gitlab/metrics/sampler_spec.rb b/spec/lib/gitlab/metrics/sampler_spec.rb
index 27211350fbe..38da77adc9f 100644
--- a/spec/lib/gitlab/metrics/sampler_spec.rb
+++ b/spec/lib/gitlab/metrics/sampler_spec.rb
@@ -9,7 +9,7 @@ describe Gitlab::Metrics::Sampler do
 
   describe '#start' do
     it 'gathers a sample at a given interval' do
-      expect(sampler).to receive(:sleep).with(5)
+      expect(sampler).to receive(:sleep).with(a_kind_of(Numeric))
       expect(sampler).to receive(:sample)
       expect(sampler).to receive(:loop).and_yield
 
@@ -116,4 +116,24 @@ describe Gitlab::Metrics::Sampler do
       sampler.add_metric('cats', value: 10)
     end
   end
+
+  describe '#sleep_interval' do
+    it 'returns a Numeric' do
+      expect(sampler.sleep_interval).to be_a_kind_of(Numeric)
+    end
+
+    # Testing random behaviour is very hard, so treat this test as a basic smoke
+    # test instead of a very accurate behaviour/unit test.
+    it 'does not return the same interval twice in a row' do
+      last = nil
+
+      100.times do
+        interval = sampler.sleep_interval
+
+        expect(interval).to_not eq(last)
+
+        last = interval
+      end
+    end
+  end
 end