[jira] [Updated] (STORM-3339) Port all the AtomicReference to ConcurrentHashMap for Nimbus

["P. Taylor Goetz (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/STORM-3339?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

P. Taylor Goetz updated STORM-3339:
-----------------------------------
    Fix Version/s:     (was: 2.0.0)

> Port all the AtomicReference to ConcurrentHashMap for Nimbus
> ------------------------------------------------------------
>
>                 Key: STORM-3339
>                 URL: https://issues.apache.org/jira/browse/STORM-3339
>             Project: Apache Storm
>          Issue Type: Improvement
>          Components: storm-core
>    Affects Versions: 2.0.0
>            Reporter: Danny Chan
>            Assignee: Danny Chan
>            Priority: Major
>
> Now for many concurrent access resource in Nimbus.java, we use AtomicReference to make them multi thread safe. The resources summarized below:
> 1. heartbeatsCache
> 2. schedulingStartTimeNs
> 3. idToSchedStatus
> 4. nodeIdToResources
> 5. idToWorkerResources
> 6. idToExecutors
> The 1, 4, 5 and 6 may grows huge if we have hundreds of topologies on cluster, when we update AtomicReference, actually we passed in a Function and use compareAndSet to update the whole val to the new returned by the Function, in that case, we must do a reference copy and merge the changes, which seems not necessary.
> I think the reason to use AtomicReference is a legacy from old Clojure code, we can replace them totally with ConcurrentHashMap which supported better performance.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)