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https://issues.apache.org/jira/browse/ARTEMIS-2823?focusedWorklogId=486992&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-486992
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ASF GitHub Bot logged work on ARTEMIS-2823:
-------------------------------------------

                Author: ASF GitHub Bot
            Created on: 21/Sep/20 15:19
            Start Date: 21/Sep/20 15:19
    Worklog Time Spent: 10m 
      Work Description: franz1981 commented on pull request #3204:
URL: https://github.com/apache/activemq-artemis/pull/3204#issuecomment-696183450


   With these last changes I believe it's nearly ok, I'm now working to check 
how it behaves with different databases.
   I will further work to make this better for the shared store use case too, 
similarly to what we do for NFS with file shared store (maybe).
   
   I've just one concern looking at the default pool configuration: the number 
of available JDBC connections in the pool and the behaviour when there are none 
available.
   
   I see that paging + large messsages can use an unbounded number of 
connections (it really depends by the concurrent thread that perform page/large 
msg streaming operations), the 2 journals requires 1 connections each (binding 
+ message journal) and the node manager requires 2 (the lease lock + the node 
manager shared state) connections.
   That means that without paging or large messages a minimum of 2 + 2 = 4 
database connections.
   The problem I see is paging and large messages: if the are too many some of 
the other operations will hang, awaiting an available connection, that means 
that probably we need to add the critical analyzer there or just let users 
knows they can configure pool appropriately.
   


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Issue Time Tracking
-------------------

    Worklog Id:     (was: 486992)
    Time Spent: 7h 50m  (was: 7h 40m)

> Improve JDBC connection management
> ----------------------------------
>
>                 Key: ARTEMIS-2823
>                 URL: https://issues.apache.org/jira/browse/ARTEMIS-2823
>             Project: ActiveMQ Artemis
>          Issue Type: Improvement
>          Components: Broker
>            Reporter: Mikko
>            Priority: Major
>          Time Spent: 7h 50m
>  Remaining Estimate: 0h
>
> I have a case where the whole clustering reliability and HA must rely on HA 
> capabilities of clustered database, and running on top of application server 
> is not an option.
> The current JDBC store implementation is rather bare bones on the connection 
> management side. JDBC driver is used directly with no management layer. At 
> startup, the broker just opens couple of direct connections to database and 
> expects them to be available forever. This is something that cannot be 
> expected in HA production environment. So, similarly to the discussion linked 
> below, in our case we lose the db connection after one hour, and all the 
> brokers need to be restared to get new connections:
> [http://activemq.2283324.n4.nabble.com/Artemis-does-not-reconnect-to-MySQL-after-connection-timeout-td4751956.html]
>  
> This is something that could be resolved by simply using JDBC4 isValid 
> checks, but proper connection handling and pooling through datasource would 
> be preferrable.
> I have implemented a solution for this by using DBCP2 datasource. Our test 
> cluster has been successfully running this forked version since the release 
> of Artemis 2.13.0. I will prepare of pull request if this is seen to be 
> something that can be useful.



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