[gstg] Enable debug command on redis-cluster-ratelimiting for resharding
Staging Change
Change Summary
We are going to horizontally scale redis-cluster-ratelimiting
redis cluster by adding a new shard (master and its slaves) into the cluster and moving some keyslots from existing masters to the new master node.
New redis shard was already provisioned here: #17888 (closed)
The change issue enables debug
command on the cluster, which is required to for resharding procedure to move redis keys on newly added master.
This is part of redis horizontal scaling: &1105 (closed)
Change Details
- Services Impacted - ServiceRedisClusterRateLimiting
-
Change Technician -
@Furhan Shabir
- Change Reviewer - @danielryan
- Time tracking - 90 minutes
- Downtime Component - none
Detailed steps for the change
Change Steps - steps to take to execute the change
Estimated Time to Complete (mins) - 90 minutes
-
Set label changein-progress /label ~change::in-progress
-
Add enable-debug-command
to chef role: https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/4699 -
Update ACL for rails
user to disallow it to executedebug
command forredis-cluster-ratelimiting
:
./bin/gkms-vault-edit redis-cluster gstg
and modify "redis-cluster-ratelimiting" hash to include -debug
for rails
user as follows
"redis-cluster-ratelimiting": {
"redis_conf": {
"masteruser": "replica",
"masterauth": "<REDACTED>",
"user": [
"default off",
"replica on ~* &* +@all ><REDACTED>",
"console on ~* &* +@all ><REDACTED>",
"redis_exporter on +client +ping +info +config|get +cluster|info +slowlog +latency +memory +select +get +scan +xinfo +type +pfcount +strlen +llen +scard +zcard +hlen +xlen +eval allkeys ><REDACTED>",
"rails on ~* &* +@all -debug ><REDACTED>"
]
}
}
-
Reconfigure the redis servers using redis-cluster-reconfigure.sh
script and instructions here:
knife search -i 'roles:gstg-base-db-redis-cluster-ratelimiting' | sort -V > redis-cluster-ratelimiting-nodes.txt
scripts/redis-cluster-reconfigure.sh redis-cluster-ratelimiting-nodes.txt
-
Set label changecomplete /label ~change::complete
Rollback
Rollback steps - steps to be taken in the event of a need to rollback this change
Estimated Time to Complete (mins) - 90 minutes
-
Revert the MR: https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/4699 -
Revert the ACL changes (if applied at this point) -
Reconfigure the redis servers using redis-cluster-reconfigure.sh
-
Set label changeaborted /label ~change::aborted
Monitoring
Key metrics to observe
-
Metric: Redis service error ratio
- Location: https://dashboards.gitlab.net/d/redis-cluster-ratelimiting-main/redis-cluster-ratelimiting3a-overview?orgId=1&var-PROMETHEUS_DS=PA258B30F88C30650&var-environment=gstg&var-shard=All&viewPanel=3422679610
- What changes to this metric should prompt a rollback: Sustained increase in the error ratio of redis server
-
Metric: Redis Cluster Slots Failed
- Location: https://dashboards.gitlab.net/d/redis-cluster-ratelimiting-main/redis-cluster-ratelimiting3a-overview?orgId=1&var-PROMETHEUS_DS=PA258B30F88C30650&var-environment=gstg&var-shard=All&viewPanel=115
- What changes to this metric should prompt a rollback: A non-zero failed slots
Change Reviewer checklist
-
Check if the following applies: - The scheduled day and time of execution of the change is appropriate.
- The change plan is technically accurate.
- The change plan includes estimated timing values based on previous testing.
- The change plan includes a viable rollback plan.
- The specified metrics/monitoring dashboards provide sufficient visibility for the change.
-
Check if the following applies: - The complexity of the plan is appropriate for the corresponding risk of the change. (i.e. the plan contains clear details).
- The change plan includes success measures for all steps/milestones during the execution.
- The change adequately minimizes risk within the environment/service.
- The performance implications of executing the change are well-understood and documented.
- The specified metrics/monitoring dashboards provide sufficient visibility for the change.
- If not, is it possible (or necessary) to make changes to observability platforms for added visibility?
- The change has a primary and secondary SRE with knowledge of the details available during the change window.
- The change window has been agreed with Release Managers in advance of the change. If the change is planned for APAC hours, this issue has an agreed pre-change approval.
- The labels blocks deployments and/or blocks feature-flags are applied as necessary.
Change Technician checklist
-
Check if all items below are complete: - The change plan is technically accurate.
- This Change Issue is linked to the appropriate Issue and/or Epic
- Change has been tested in staging and results noted in a comment on this issue.
- A dry-run has been conducted and results noted in a comment on this issue.
- The change execution window respects the Production Change Lock periods.
- For C1 and C2 change issues, the change event is added to the GitLab Production calendar.
- For C1 and C2 change issues, the SRE on-call has been informed prior to change being rolled out. (In #production channel, mention
@sre-oncall
and this issue and await their acknowledgement.) - For C1 and C2 change issues, the SRE on-call provided approval with the eoc_approved label on the issue.
- For C1 and C2 change issues, the Infrastructure Manager provided approval with the manager_approved label on the issue.
- Release managers have been informed prior to any C1, C2, or blocks deployments change being rolled out. (In #production channel, mention
@release-managers
and this issue and await their acknowledgment.) - There are currently no active incidents that are severity1 or severity2
- If the change involves doing maintenance on a database host, an appropriate silence targeting the host(s) should be added for the duration of the change.
Edited by Furhan Shabir