You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@ambari.apache.org by "Siddharth Wagle (JIRA)" <ji...@apache.org> on 2015/10/22 03:32:27 UTC

[jira] [Updated] (AMBARI-13517) Ambari Server JVM crashed after several clicks in Web UI to navigate graph timerange

     [ https://issues.apache.org/jira/browse/AMBARI-13517?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Siddharth Wagle updated AMBARI-13517:
-------------------------------------
    Description: 
- Max Heap restriction problem: Ehcache library that we use has a limit of how far in the object graph it traverses to find size of an Cached reference, this is to make it performant. Default limit = 1000.
- User gets following Warning which are harmless unless the data cannot fit in memory and eviction does not kick in:
{code}
WARN [qtp-client-70] ObjectGraphWalker:209 - The configured limit of 1,000 object references was reached while attempting to calculate the size of the object graph. Severe performance degradation could occur 
if the sizing operation continues. This can be avoided by setting the CacheManger or Cache <sizeOfPolicy> elements maxDepthExceededBehavior to "abort" or adding stop points with @IgnoreSizeOf annotations. If performance degradation 
is NOT an issue at the configured limit, raise the limit value using the CacheManager or Cache <sizeOfPolicy> elements maxDepth attribute. For more information, see the Ehcache configuration documentation.
{code}

_Objective of the patch_:
- Provide a custom Sizing engine for Ehcache that will provide a close approximation of the data in the cache with significant perf gain. Premise: Since we know the data structures we can make better estimates.
- Expectation from sizing engine : Discrepancy of less than 10K for a DS of size 10 MB (Proven with a unit test)

  was:
Max Heap restriction problem: Ehcache library that we use has a limit of how far in the object graph it traverses to find size of an Cached reference, this is to make it performant. Default limit = 1000.
_Objective of the patch_:
- Provide a custom Sizing engine for Ehcache that will provide a close approximation of the data in the cache with significant perf gain. Premise: Since we know the data structures we can make better estimates.
- Expectation from sizing engine : Discrepancy of less than 10K for a DS of size 10 MB (Proven with a unit test)


> Ambari Server JVM crashed after several clicks in Web UI to navigate graph timerange
> ------------------------------------------------------------------------------------
>
>                 Key: AMBARI-13517
>                 URL: https://issues.apache.org/jira/browse/AMBARI-13517
>             Project: Ambari
>          Issue Type: Bug
>          Components: ambari-server
>    Affects Versions: 2.1.2
>            Reporter: Siddharth Wagle
>            Assignee: Siddharth Wagle
>            Priority: Critical
>             Fix For: 2.1.3
>
>
> - Max Heap restriction problem: Ehcache library that we use has a limit of how far in the object graph it traverses to find size of an Cached reference, this is to make it performant. Default limit = 1000.
> - User gets following Warning which are harmless unless the data cannot fit in memory and eviction does not kick in:
> {code}
> WARN [qtp-client-70] ObjectGraphWalker:209 - The configured limit of 1,000 object references was reached while attempting to calculate the size of the object graph. Severe performance degradation could occur 
> if the sizing operation continues. This can be avoided by setting the CacheManger or Cache <sizeOfPolicy> elements maxDepthExceededBehavior to "abort" or adding stop points with @IgnoreSizeOf annotations. If performance degradation 
> is NOT an issue at the configured limit, raise the limit value using the CacheManager or Cache <sizeOfPolicy> elements maxDepth attribute. For more information, see the Ehcache configuration documentation.
> {code}
> _Objective of the patch_:
> - Provide a custom Sizing engine for Ehcache that will provide a close approximation of the data in the cache with significant perf gain. Premise: Since we know the data structures we can make better estimates.
> - Expectation from sizing engine : Discrepancy of less than 10K for a DS of size 10 MB (Proven with a unit test)



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)