[
https://issues.apache.org/jira/browse/ARTEMIS-3289?focusedWorklogId=597210&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-597210
]
ASF GitHub Bot logged work on ARTEMIS-3289:
-------------------------------------------
Author: ASF GitHub Bot
Created on: 15/May/21 12:59
Start Date: 15/May/21 12:59
Worklog Time Spent: 10m
Work Description: franz1981 commented on pull request #3572:
URL: https://github.com/apache/activemq-artemis/pull/3572#issuecomment-841655602
@clebertsuconic @gtully
I'm not totally sold about the current semantic while checking for record ID
presence: if `sync == false` (as `ReplicationEndpoint`) it seems that
`JournalBase` is going to use `DummyCallback.getInstance()` as callback,
meaning that it won't expect to block *ever*, but the existing semantic that
check for record presence will make the caller thread to block until the record
presence is verified, is it correct?
I would expect instead that if `sync == false` the caller thread won't get
any error back, if not for something that can be verified on the same thread eg
the new lock-free `knownRecordID` check.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
Issue Time Tracking
-------------------
Worklog Id: (was: 597210)
Time Spent: 1.5h (was: 1h 20m)
> Reduce journal appender executor Thread wakeup cost
> ---------------------------------------------------
>
> Key: ARTEMIS-3289
> URL: https://issues.apache.org/jira/browse/ARTEMIS-3289
> Project: ActiveMQ Artemis
> Issue Type: Improvement
> Reporter: Francesco Nigro
> Assignee: Francesco Nigro
> Priority: Major
> Attachments: image-2021-05-11-09-32-15-538.png
>
> Time Spent: 1.5h
> Remaining Estimate: 0h
>
> As mentioned in https://issues.apache.org/jira/browse/ARTEMIS-2877 one of the
> major factors that contribute to reduce the scalability of a shared-nothing
> replication setup is the thread wake-up cost of the {{JournalImpl}}'s
> {{appendExecutor}} I/O threads.
> See the flamegraph below for a busy replica while appending replicated
> journal record:
> !image-2021-05-11-09-32-15-538.png|width=966,height=313!
> The violet bars represent the CPU cycles spent to awake the Journal appender
> thread(s): despite https://issues.apache.org/jira/browse/ARTEMIS-2877 allow
> backup to batch append tasks as much as possible, it seems the signaling cost
> is still too high, if compared with the rest of replica packet processing.
> Given that the append executor is an ordered executor built on top of I/O
> thread pool, see {{ActiveMQServerImpl}}:
> {code:java}
> if (serviceRegistry.getIOExecutorService() != null) {
> this.ioExecutorFactory = new
> OrderedExecutorFactory(serviceRegistry.getIOExecutorService());
> } else {
> ThreadFactory tFactory = AccessController.doPrivileged(new
> PrivilegedAction<ThreadFactory>() {
> @Override
> public ThreadFactory run() {
> return new ActiveMQThreadFactory("ActiveMQ-IO-server-" +
> this.toString(), false, ClientSessionFactoryImpl.class.getClassLoader());
> }
> });
> this.ioExecutorPool = new ThreadPoolExecutor(0, Integer.MAX_VALUE,
> 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), tFactory);
> this.ioExecutorFactory = new OrderedExecutorFactory(ioExecutorPool);
> }
> {code}
> And it's using a {{SynchronousQueue}} to submit/take new wakeup tasks, it
> worths investigate if using a different thread pool, executor or a different
> "sleeping" strategy could reduce such cost under heavy load and improve
> response time with/without replication.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
