support pausing rolling-update of TidbCluster

[aylei]

Feature Request

Scenarios:

• For critical env, pause could be used to avoid unexpected rolling-update caused by a compatible issue of new operator version or an operation error (user fault).
• Support user to modify the spec multiple times and only apply once, or only apply at maintenance window.

Reference:

• Pause support of Deployment

[Yisaer]

Currently, we already supported this feature. #1377 moved sts webhook config in templates and exposed webhook switch in values.yaml. When users enabled admissionWebhook and statefulset hook, they can pause tidbcluster by adding annotations for tidbcluster object.
@aylei

[aylei]

I suppose you are talking about the annotations (tidb.pingcap.com/tidb-partition", tidb.pingcap.com/tikv-partition) for canary release? In some extent it meets the requirement, but it is not actually pause the all the controlling that would mutate cluster pods

[Yisaer]

@aylei It seems that this feature requests a method like annotate tidb.pingcap.com/pause to tidbcluster to pause the upgarding without specific the canary release number.

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 15 days

[cofyc]

related incompatibility issues:

• slowLogTailer: rotated slow logs not cleaned  #1779
• support starting tidb-server with -advertise-address parameter #1859