accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From ShawnWalker <...@git.apache.org>
Subject [GitHub] accumulo pull request: ACCUMULO-4191 Tracing on client can sometim...
Date Fri, 15 Apr 2016 17:11:50 GMT
Github user ShawnWalker commented on the pull request:

    https://github.com/apache/accumulo/pull/94#issuecomment-210550520
  
    @joshelser 
    > I was looking for some understanding that you ... had a plausible idea of why this
was sometimes happening. Sounds fine to me.
    
    It seemed obvious to me that not propagating the tracing was an error.  Before you asked,
I had just decided it was "some random race condition".  Coming up with a plausible explanation
made me read what was going on much more closely.
    
    If this really is broken for everyone on master, there's a much more plausible explanation
why it might have occasionally failed before:  the `TimerTask` created at `TabletServerBatchWriter`
line 210 can cause mutations to be sent without propagating the tracing information.  Particularly
the fact that it has an initial delay of 0 would make for a timing sensitive race condition:
 either {{close()}} arranges to send the mutations (traceable) or the timer arranges to send
the mutations (untraceable).
    
    Fixing the timer task to propagate tracing would not be quite so trivial a task as the
patch proposed in this pull request.



---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message