[teiid-issues] [JBoss JIRA] (TEIID-4734) Under some circumstances after restart Teiid Server does not update Materialized views anymore

[Ramesh Reddy (JIRA)]

    [ https://issues.jboss.org/browse/TEIID-4734?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13355912#comment-13355912 ] 

Ramesh Reddy commented on TEIID-4734:
-------------------------------------

When a materialized view is being loaded (external), the {{LoadStatus}} on the {{Status}} is set to "loading". If in the event of server is stopped/restarted then process which is loading the materialized view will be killed and loading of the view is incomplete. Since the server lifecycle events are either not captured or check against with {{Status}} table, when the server comes back up, the internal scheduler that monitors and reloads of materialization views based {{LoadStatus}} in the {{Status}} table assumes that, currently there is a process that is still running the load of materialized view and ignores starting a new process to load the materialized view, thus the view never gets updated.

Proposal:

We can add a additional column to the {{Status}} table called {{NodeName}} that represents the server node name that is loading a materialized view. During the starting of a server, we can introduce a scan of {{Status}} table with that particular server's node name and remove any "loading" status and convert them to "needs_loading" status such that next time the internal scheduler runs it will start updating the view again.

Comments?

> Under some circumstances after restart Teiid Server does not update Materialized views anymore
> ----------------------------------------------------------------------------------------------
>
>                 Key: TEIID-4734
>                 URL: https://issues.jboss.org/browse/TEIID-4734
>             Project: Teiid
>          Issue Type: Bug
>          Components: Common
>    Affects Versions: 9.1.2
>         Environment: * Wildfly 10
> * MySQL 5.6.32
> * Teiid Server 9.1.2
>            Reporter: Pedro Inácio
>            Assignee: Steven Hawkins
>         Attachments: StatusTableAfterStart.csv, StatusTableAfterStop.csv
>
>
> Under some circumstances, start and stop the server several times at different points, some Materialized Views are not being updated by the server.
> It is observable that in status table some views are no longer updated. In server log are being printed lots of INFO lines.
> Waited more than 15 minutes and the server was not capable of recovering.
> See the _StatusTableAfterStop.csv_ file to observe the status table content after stopping the server.
> See the _StatusTableAfterStart.csv_ file to observe the status table content after approximately 15 minutes after restart.
> Check _server.log_  for the Teiid Server log.
> See that hundreds of lines similar to the following occur
> {panel:title=Server.log}
> 2017-01-31 13:06:34,597 INFO  [org.teiid.COMMAND_LOG] (Teiid Timer0) JfGY9cInAbrb 	START USER COMMAND:	startTime=2017-01-31 13:06:34.597	requestID=JfGY9cInAbrb.0	txID=null	sessionID=JfGY9cInAbrb	applicationName=internal	principal=embedded-async	vdbName=CountryServiceListVDB	vdbVersion=1	sql=execute SYSADMIN.matViewStatus('NumberingPlan', 'numbering_plan')
> {panel}
> The server cannot continue to load materialized views.



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