Re-organize queues to use for Sidekiqseparate-sidekiq-queues

Dumping too many jobs in the same queue (e.g. the "default" queue) is a
dangerous setup. Jobs that take a long time to process can effectively
block any other work from being performed given there are enough of
these jobs.

Furthermore it becomes harder to monitor the jobs as a single queue
could contain jobs for different workers. In such a setup the only
reliable way of getting counts per job is to iterate over all jobs in a
queue, which is a rather time consuming process.

By using separate queues for various workers we have better control over
throughput, we can add weight to queues, and we can monitor queues
better. Some workers still use the same queue whenever their work is
related. For example, the various CI pipeline workers use the same
"pipeline" queue.

This commit includes a Rails migration that moves Sidekiq jobs from the
old queues to the new ones. This migration also takes care of doing the
inverse if ever needed. This does require downtime as otherwise new jobs
could be scheduled in the old queues after this migration completes.

This commit also includes an RSpec test that blacklists the use of the
"default" queue and ensures cron workers use the "cronjob" queue.

Fixes gitlab-org/gitlab-ce#23370

1 files changed, 46 insertions, 0 deletions

diff --git a/config/sidekiq_queues.yml b/config/sidekiq_queues.yml
new file mode 100644
index 00000000000..c2e880e891f
--- /dev/null
+++ b/config/sidekiq_queues.yml
@@ -0,0 +1,46 @@
+# This configuration file should be exclusively used to set queue settings for
+# Sidekiq. Any other setting should be specified using the Sidekiq CLI or the
+# Sidekiq Ruby API (see config/initializers/sidekiq.rb).
+---
+# All the queues to process and their weights. Every queue _must_ have a weight
+# defined.
+#
+# The available weights are as follows
+#
+# 1: low priority
+# 2: medium priority
+# 3: high priority
+# 5: _super_ high priority, this should only be used for _very_ important queues
+#
+# As per http://stackoverflow.com/a/21241357/290102 the formula for calculating
+# the likelihood of a job being popped off a queue (given all queues have work
+# to perform) is:
+#
+#     chance = (queue weight / total weight of all queues) * 100
+:queues:
+  - [post_receive, 5]
+  - [merge, 5]
+  - [update_merge_requests, 3]
+  - [new_note, 2]
+  - [build, 2]
+  - [pipeline, 2]
+  - [gitlab_shell, 2]
+  - [email_receiver, 2]
+  - [emails_on_push, 2]
+  - [repository_fork, 1]
+  - [repository_import, 1]
+  - [project_service, 1]
+  - [clear_database_cache, 1]
+  - [delete_user, 1]
+  - [expire_build_instance_artifacts, 1]
+  - [group_destroy, 1]
+  - [irker, 1]
+  - [project_cache, 1]
+  - [project_destroy, 1]
+  - [project_export, 1]
+  - [project_web_hook, 1]
+  - [repository_check, 1]
+  - [system_hook, 1]
+  - [git_garbage_collect, 1]
+  - [cronjob, 1]
+  - [default, 1]