[
https://issues.apache.org/jira/browse/IGNITE-19047?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17737062#comment-17737062
]
Aleksandr Polovtcev commented on IGNITE-19047:
----------------------------------------------
Thank you, the issue is much clearer now!
> Implement metastorage and cmg raft log re-application in async manner
> ---------------------------------------------------------------------
>
> Key: IGNITE-19047
> URL: https://issues.apache.org/jira/browse/IGNITE-19047
> Project: Ignite
> Issue Type: Improvement
> Reporter: Alexander Lapin
> Priority: Major
> Labels: ignite-3
>
> h3. Motivation
> In order to prevent inconsistent reads, raft replays local stable raft log on
> raft node restart in see org.apache.ignite.raft.jraft.core.NodeImpl#init.
> However, occurred that such approach led to a deadlock:
> 1. Restart of the table waited for the raft log to replay.
> 2. Log record waiter for index to be ready.
> 3. Index manager waited the table to be created to create index on top of it,
> that is awaited in step 2.
> Given issue was addressed in
> https://issues.apache.org/jira/browse/IGNITE-18203 and later slightly updated
> in https://issues.apache.org/jira/browse/IGNITE-19022 in a way that
> logApplyComplition future was introduced that is completed when all local
> stable log records are applied (org.apache.ignite.raft.jraft.core.NodeImpl):
> {code:java}
> public boolean init(final NodeOptions opts) {
> ...
> // Wait committed.
> long commitIdx = logManager.getLastLogIndex();
> CompletableFuture<Long> logApplyComplition = new CompletableFuture<>();
> if (commitIdx > fsmCaller.getLastAppliedIndex()) {
> LastAppliedLogIndexListener lnsr = new LastAppliedLogIndexListener() {
> @Override
> public void onApplied( long lastAppliedLogIndex) {
> if (lastAppliedLogIndex >= commitIdx) {
> logApplyComplition.complete(lastAppliedLogIndex);
> ...
> }
> }
> };
> ...
> }{code}
> Depending on replication group type given logApplyComplition is either blocks
> access to restoring data until ready or is synchronously awaited on start.
> For meta storage and CMG latter is used
> (org.apache.ignite.internal.raft.Loza).
> {code:java}
> public CompletableFuture<RaftGroupService> startRaftGroupNode(
> RaftNodeId nodeId,
> PeersAndLearners configuration,
> RaftGroupListener lsnr,
> RaftGroupEventsListener eventsLsnr
> ) throws NodeStoppingException {
> ...
> // TODO: https://issues.apache.org/jira/browse/IGNITE-19047 Meta storage
> and cmg raft log re-application in async manner
> raftServer.raftNodeReadyFuture(nodeId.groupId()).join();
> ...
> } {code}
> For partitions, access is blocked until local recovery is finished, see
> org.apache.ignite.internal.replicator.Replica#ready usage for more details.
> h3. Definition of Done
> * Implement meta storage and cmg raft log re-application in async manner
> like it's done for partitions.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
