[jira] [Commented] (ZOOKEEPER-1657) Increased CPU usage by unnecessary SASL checks

["Hadoop QA (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ZOOKEEPER-1657?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13756435#comment-13756435 ] 

Hadoop QA commented on ZOOKEEPER-1657:
--------------------------------------

+1 overall.  Here are the results of testing the latest attachment 
  http://issues.apache.org/jira/secure/attachment/12601126/ZOOKEEPER-1657.patch
  against trunk revision 1519515.

    +1 @author.  The patch does not contain any @author tags.

    +1 tests included.  The patch appears to include 3 new or modified tests.

    +1 javadoc.  The javadoc tool did not generate any warning messages.

    +1 javac.  The applied patch does not increase the total number of javac compiler warnings.

    +1 findbugs.  The patch does not introduce any new Findbugs (version 1.3.9) warnings.

    +1 release audit.  The applied patch does not increase the total number of release audit warnings.

    +1 core tests.  The patch passed core unit tests.

    +1 contrib tests.  The patch passed contrib unit tests.

Test results: https://builds.apache.org/job/PreCommit-ZOOKEEPER-Build/1554//testReport/
Findbugs warnings: https://builds.apache.org/job/PreCommit-ZOOKEEPER-Build/1554//artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Console output: https://builds.apache.org/job/PreCommit-ZOOKEEPER-Build/1554//console

This message is automatically generated.
                
> Increased CPU usage by unnecessary SASL checks
> ----------------------------------------------
>
>                 Key: ZOOKEEPER-1657
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1657
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: java client
>    Affects Versions: 3.4.5
>            Reporter: Gunnar Wagenknecht
>            Assignee: Philip K. Warren
>              Labels: performance
>             Fix For: 3.5.0, 3.4.6
>
>         Attachments: ZOOKEEPER-1657.patch, ZOOKEEPER-1657.patch, ZOOKEEPER-1657.patch, ZOOKEEPER-1657.patch, ZOOKEEPER-1657.patch, zookeeper-hotspot-gone.png, zookeeper-hotspot.png
>
>
> I did some profiling in one of our Java environments and found an interesting footprint in ZooKeeper. The SASL support seems to trigger a lot times on the client although it's not even in use.
> Is there a switch to disable SASL completely?
> The attached screenshot shows a 10-minute profiling session on one of our production Jetty servers. The Jetty server handles ~1k web requests per minute. The average response time per web request is a few milli seconds. The profiling was performed on a machine running for >24h. 
> We noticed a significant CPU increase on our servers when deploying an update from ZooKeeper 3.3.2 to ZooKeeper 3.4.5. Thus, we started investigating. The screenshot shows that only 32% CPU time are spent in Jetty. In contrast, 65% are spend in ZooKeeper. 
> A few notes/thoughts:
> * {{ClientCnxn$SendThread.clientTunneledAuthenticationInProgress}} seems to be the culprit
> * {{javax.security.auth.login.Configuration.getConfiguration}} seems to be called very often?
> * There is quite a bit reflection involved in {{java.security.AccessController.doPrivileged}}
> * No security manager is active in the JVM: I tend to place an if-check in the code before calling {{AccessController.doPrivileged}}. When no SM is installed, the runnable can be called directly which safes cycles.

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