[jira] [Resolved] (AMBARI-11394) Blueprint cluster provision occasionally fails due to out of order database writes

["John Speidel (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/AMBARI-11394?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

John Speidel resolved AMBARI-11394.
-----------------------------------
    Resolution: Fixed

merged to trunk

> Blueprint cluster provision occasionally fails due to out of order database writes
> ----------------------------------------------------------------------------------
>
>                 Key: AMBARI-11394
>                 URL: https://issues.apache.org/jira/browse/AMBARI-11394
>             Project: Ambari
>          Issue Type: Bug
>    Affects Versions: 2.1.0
>            Reporter: John Speidel
>            Assignee: John Speidel
>             Fix For: 2.1.0
>
>
> Provisioning a cluster may occasionally fail to complete as a result of an out of order database write.
> This error presents itself as start task(s) that never progresses beyond the PENDING state.  For these logical pending tasks, there are no associated physical tasks.
> When a host is matched to a host request, an install request is submitted followed immediately by a start request.  The install task transitions all host components desired_state for the host from INIT to INSTALLED.  But, because of an error in the persistence layer, after the desired_state is set to INSTALLED, it is overwritten on another thread (heartbeat handler thread) to INIT.  As a result, the component is never started because it it's desired state is INIT and isn't processed by the start operation.
> The root cause of this is that  the public method ServiceComponentHostImpl.handleEvent() is annotated with '@Transactional'.  Inside of this method the proper locks are acquired, BUT because this method is marked as @Transactional it's invocation is wrapped in a proxy which wraps the method invocation in a transaction.  As a result, the transaction is committed in the proxy after the method returns outside of any synchronization which allows for out of order writes.  



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