>From Ian Maxon <[email protected]>:

Attention is currently required from: Ali Alsuliman, Ali Alsuliman, Michael 
Blow.

Ian Maxon has posted comments on this change by Ian Maxon. ( 
https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/20270?usp=email )

Change subject: [ASTERIXDB-3631][RT] Profile nested groupby clauses
......................................................................


Patch Set 8:

(1 comment)

File 
hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/StatsCollector.java:

https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/20270/comment/e95a9195_80fda2df?usp=email
 :
PS8, Line 38:     private final Map<String, IOperatorStats> operatorStatsMap = 
new ConcurrentHashMap<>();
> > i don't believe so. […]
indeed, i talked with Ali and (as usual from speaking with him) things became 
clear. one thing is that i wasn't reading happens-before as a proper noun. the 
other faulty assumption was that NotifyTaskCompleteWork and the end a Task have 
a happens-before relationship. it turns out we simply schedule that thread at 
the end of run() in Task, but it has a reference to the Task that started it. 
so it can access things in an inconsistent manner.

many of the things it reads from Task are final, but some (like the stats, 
partition profiles, and warnings) are definitely not. using a ConcurrentHashMap 
alone won't work because the size() is basically just an estimate, and an 
Iterator will give you something and never throw 
ConcurrentModificationException, but that isn't what we want. for some reason i 
was thinking size() in ConcurrentHashMap was basically "volatile" but i don't 
know how i came to that idea.



--
To view, visit https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/20270?usp=email
To unsubscribe, or for help writing mail filters, visit 
https://asterix-gerrit.ics.uci.edu/settings?usp=email

Gerrit-MessageType: comment
Gerrit-Project: asterixdb
Gerrit-Branch: master
Gerrit-Change-Id: I516dc90b8da3a7086dc80b67946ac14f6ade0973
Gerrit-Change-Number: 20270
Gerrit-PatchSet: 8
Gerrit-Owner: Ian Maxon <[email protected]>
Gerrit-Reviewer: Ali Alsuliman <[email protected]>
Gerrit-Reviewer: Ali Alsuliman <[email protected]>
Gerrit-Reviewer: Anon. E. Moose #1000171
Gerrit-Reviewer: Ian Maxon <[email protected]>
Gerrit-Reviewer: Jenkins <[email protected]>
Gerrit-CC: Michael Blow <[email protected]>
Gerrit-Attention: Ali Alsuliman <[email protected]>
Gerrit-Attention: Ali Alsuliman <[email protected]>
Gerrit-Attention: Michael Blow <[email protected]>
Gerrit-Comment-Date: Thu, 18 Dec 2025 00:17:27 +0000
Gerrit-HasComments: Yes
Gerrit-Has-Labels: No
Comment-In-Reply-To: Ian Maxon <[email protected]>
Comment-In-Reply-To: Ali Alsuliman <[email protected]>
Comment-In-Reply-To: Michael Blow <[email protected]>

Reply via email to