Discovery timeouts, emergency read operations throttled by discovery timeouts #1351
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…nterval Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
MOON-CLJ
reviewed
Aug 7, 2021
| @@ -45,6 +45,8 @@ func (applier *CommandApplier) ApplyCommand(op string, value []byte) interface{} | |||
| return applier.registerNode(value) | |||
| case "discover": | |||
| return applier.discover(value) | |||
| case "async-discover": | |||
| return applier.asyncDiscover(value) | |||
There was a problem hiding this comment.
@shlomi-noach should publishDiscoverMasters also use async-discover?
because sync discover can slow down the raft log apply。
cc @yangeagle
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Followup to an issue reported outside this repo.
Scenario:
ReadTopologyInstanceBufferable(the main discovery function) runs again and again, totaling 3 concurrent executions, exhausting the connection pool limit for this instance.api/discover/the-instance/3306are blocked on this instanceorchestrator/raftsetup, someone callsapi/discover/the-instance/3306Description
Timeouts already configured at DSN level. We add:
context.WithTimeout()inReadTopologyInstanceBufferable, now usingdb.QueryRowContext()andsqlutils.QueryRowsMapContext()topology_recovery.go,emergentlyReadTopologyInstance()only runs at most 1 read (for a given instance) perMySQLDiscoveryReadTimeoutSeconds, to avoid further spamming the instance.Expected result: worst case scenario an operation will hang up to
MySQLDiscoveryReadTimeoutSeconds(configurable, default:10)