kvserver: add cluster setting to disable transactionally writing node…

[shralex]

… and range events into system tables

Currently splits, merges, and rebalances all log transactionally to the system.rangelog table.
Node membership events are logged into the system.eventlog table. This introduces a dependency
that can cause issues when these system tables are unavailable. This PR introduces a cluster
setting to disable writing these events. Note that decommissioning events aren't control by
this setting and are always written.

Release note: a new cluster setting (kv.log_range_and_node_events.enabled) is introduced to
disable transactionally logging range events (e.g., merges, splits and rebalancing)
and node join and restart events to system tables, to remove the dependency on such tables
and improve performance.

Release justification: stability improvement

FIxes #82535

[cockroach-teamcity]

This change is 

[knz]

Tip: make the bool a DisableXXX, so that the go default value (false) ensures that the previous behavior (logs enabled) is preserved.

Also, you'll need to update the initialization code in various places that set that boolean to the desired default value, for use in tests.

I'm also curious as to why the cluster setting is only used in some places and not all, and why there's no opt-out for decommissioning events.

Also, nit, the commit message contains some stray sentences.

[nvanbenschoten]

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @nvanbenschoten and @shralex)

---

pkg/kv/kvserver/log.go line 82 at r1 (raw file):

	}

	if !s.cfg.LogRangeAndNodeEvents && !logRangeAndNodeEventsEnabled.Get(&s.ClusterSettings().SV) {

Should this be if !s.cfg.LogRangeAndNodeEvents || !logRangeAndNodeEventsEnabled.Get(&s.ClusterSettings().SV)?

---

pkg/kv/kvserver/store.go line 1111 at r1 (raw file):

			" (e.g., split, merge, add/remove voter/non-voter) into system.rangelog"+
			"and node join and restart events into system.eventolog",
		false,

Don't we want this to default to true?

[nvanbenschoten]

thanks!

Reviewed 2 of 4 files at r1, 2 of 2 files at r2, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @shralex)

[ajwerner]

This is something on my radar. The dependency of the low-level transactions on the internal executor leads to special cases I'm going to need to eliminate in 23.1. My plan was to just use the raw KV API to perform these writes. If we're going to just get rid of the writes, that also makes me happy. I'll file an issue tomorrow, just writing this out as I see it fly by.

[knz]

Have you considered something akin to the new code for system.eventlog, which performs these writes async now?

[shralex]

bors r+

[craig]

This PR was included in a batch that timed out, it will be automatically retried

[shralex]

bors r+

[craig]

Already running a review

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)