Add latest changes from gitlab-org/gitlab@master

1 files changed, 45 insertions, 13 deletions

diff --git a/doc/administration/operations/sidekiq_memory_killer.md b/doc/administration/operations/sidekiq_memory_killer.md
index 8eac42f2fe2..509bc77a8c3 100644
--- a/doc/administration/operations/sidekiq_memory_killer.md
+++ b/doc/administration/operations/sidekiq_memory_killer.md
@@ -26,18 +26,50 @@ run as a process group leader (e.g., using `chpst -P`). If using Omnibus or the
 
 The MemoryKiller is controlled using environment variables.
 
-- `SIDEKIQ_MEMORY_KILLER_MAX_RSS`: if this variable is set, and its value is
-  greater than 0, then after each Sidekiq job, the MemoryKiller will check the
-  RSS of the Sidekiq process that executed the job. If the RSS of the Sidekiq
-  process (expressed in kilobytes) exceeds SIDEKIQ_MEMORY_KILLER_MAX_RSS, a
-  delayed shutdown is triggered. The default value for Omnibus packages is set
+- `SIDEKIQ_DAEMON_MEMORY_KILLER`: defaults to 0. When set to 1, the MemoryKiller
+  works in _daemon_ mode. Otherwise, the MemoryKiller works in _legacy_ mode.
+
+  In _legacy_ mode, the MemoryKiller checks the Sidekiq process RSS after each job.
+
+  In _daemon_ mode, the MemoryKiller checks the Sidekiq process RSS every 3 seconds
+  (defined by `SIDEKIQ_MEMORY_KILLER_CHECK_INTERVAL`).
+
+- `SIDEKIQ_MEMORY_KILLER_MAX_RSS`: if this variable is set, and its value is greater
+  than 0, the MemoryKiller is enabled. Otherwise the MemoryKiller is disabled.
+
+  `SIDEKIQ_MEMORY_KILLER_MAX_RSS` defines the Sidekiq process allowed RSS.
+
+  In _legacy_ mode, if the Sidekiq process exceeds the allowed RSS then an irreversible
+  delayed graceful restart will be triggered. The restart of Sidekiq will happen
+  after `SIDEKIQ_MEMORY_KILLER_GRACE_TIME` seconds.
+
+  In _daemon_ mode, if the Sidekiq process exceeds the allowed RSS for longer than
+  `SIDEKIQ_MEMORY_KILLER_GRACE_TIME` the graceful restart will be triggered. If the
+  Sidekiq process go below the allowed RSS within `SIDEKIQ_MEMORY_KILLER_GRACE_TIME`,
+  the restart will be aborted.
+
+  The default value for Omnibus packages is set
   [in the omnibus-gitlab
   repository](https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/files/gitlab-cookbooks/gitlab/attributes/default.rb).
-- `SIDEKIQ_MEMORY_KILLER_GRACE_TIME`: defaults to 900 seconds (15 minutes). When
-  a shutdown is triggered, the Sidekiq process will keep working normally for
-  another 15 minutes.
-- `SIDEKIQ_MEMORY_KILLER_SHUTDOWN_WAIT`: defaults to 30 seconds. When the grace
-  time has expired, the MemoryKiller tells Sidekiq to stop accepting new jobs.
-  Existing jobs get 30 seconds to finish. After that, the MemoryKiller tells
-  Sidekiq to shut down, and an external supervision mechanism (e.g. Runit) must
-  restart Sidekiq.
+
+- `SIDEKIQ_MEMORY_KILLER_HARD_LIMIT_RSS`: is used by _daemon_ mode. If the Sidekiq
+  process RSS (expressed in kilobytes) exceeds `SIDEKIQ_MEMORY_KILLER_HARD_LIMIT_RSS`,
+  an immediate graceful restart of Sidekiq is triggered.
+
+- `SIDEKIQ_MEMORY_KILLER_CHECK_INTERVAL`: used in _daemon_ mode to define how
+  often to check process RSS, default to 3 seconds.
+
+- `SIDEKIQ_MEMORY_KILLER_GRACE_TIME`: defaults to 900 seconds (15 minutes).
+  The usage of this variable is described as part of `SIDEKIQ_MEMORY_KILLER_MAX_RSS`.
+
+- `SIDEKIQ_MEMORY_KILLER_SHUTDOWN_WAIT`: defaults to 30 seconds. This defines the
+  maximum time allowed for all Sidekiq jobs to finish. No new jobs will be accepted
+  during that time, and the process will exit as soon as all jobs finish.
+
+  If jobs do not finish during that time, the MemoryKiller will interrupt all currently
+  running jobs by sending `SIGTERM` to the Sidekiq process.
+
+  If the process hard shutdown/restart is not performed by Sidekiq,
+  the Sidekiq process will be forcefully terminated after
+  `Sidekiq.options[:timeout] * 2` seconds. An external supervision mechanism
+  (e.g. Runit) must restart Sidekiq afterwards.