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https://issues.apache.org/activemq/browse/AMQ-1244?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_39271
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James Strachan commented on AMQ-1244:
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A few thoughts. Firstly note that this locking transaction never updates any
data and never needs to be replicated.
Couldn't the replication server just ignore the lock table? Or we could allow
the lock table to be in a different schema (logical database) if that helps?
There needs to be some table used for locking; as we need to ensure multiple
brokers don't write to the same logical database. Though by all means suggest a
suitable workaround that works for you with database replication; would
ignoring the table, or moving it to a separate logical database/schema work?
Worst case scenario; we could use a completely separate database entirely (even
a different JDBC provider! :) but I'd rather reuse the same DataSource if we
can (it makes things much simpler to code and removes a multitude of possible
issues such as folks using a local Derby DB for the lock :)
> DatabaseLocker implementation impedes database replication
> ----------------------------------------------------------
>
> Key: AMQ-1244
> URL: https://issues.apache.org/activemq/browse/AMQ-1244
> Project: ActiveMQ
> Issue Type: Bug
> Components: Message Store
> Affects Versions: 4.1.1
> Environment: Latest ActiveMQ snapshot, Sybase ASE 12.5.x
> Reporter: Marcos Sanz
> Priority: Critical
>
> The current implementation of the JDBC Master/Slave feature makes one broker
> (the master) acquire a lock on a database object. In Sybase, this has been
> implemented with the command:
> LOCK TABLE foo IN EXCLUSIVE MODE
> This command can only be executed within a transaction, see:
> http://manuals.sybase.com/onlinebooks/group-as/asg1250e/sqlug/@Generic__BookTextView/54552;pt=54651
> This implies that for the whole lifespan of the ActiveMQ-process there is an
> open transaction in the RDBMS. This is a problem in a professional
> environment making use of a database replication server: The open transaction
> impedes that the transaction log in the active database is emptied, then the
> stable queue at the replication server won't be purged and will steadily grow
> up to infinitum. We have been able to observe this behaviour.
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