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1. Re: HA Failover in shared-store configuration
clebert.suconic Jun 4, 2010 4:15 PM (in response to johncprout)** using NFS mount **
don't use NFS with the Journal. You need local access to the disk.
When we mean shared store, that's over a SAN. (Not just simple NFS).
Any DB requires local disk, as you need to guarantee syncs and other stuff, what I'm not sure it can be done through simple NFS.
What happens with Failover is... when the client connect to the node, that node is activate. For that you need to configure the backup node on the ConnectionFactory, what could be done through UDP discovery or direct configuration. Look at the documentation for more details.
BTW: You should be using 2.1.0.Final. (You didn't mention what version you were using)
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2. Re: HA Failover in shared-store configuration
johncprout Jun 4, 2010 4:29 PM (in response to clebert.suconic)Thanks for the reply
Regarding NFS - I could be using the wrong term, since I'm no Unix expert; this is a mount point that targets a file server. In production, this will certainly be on a SAN, but I don't have that available for development.
The problem with my scenario is that when the Live server fails, there won't be any client left to failover, since the client/Producer is on the same server as the Live Consumer and that server is dead. Am I mis-understanding what's meant by the Client?
John
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3. Re: HA Failover in shared-store configuration
clebert.suconic Jun 4, 2010 5:20 PM (in response to johncprout)The node will be activated when the first client is activated..
There's currently also a JIRA opened onward of 2.2 to make MDBs passive until the server is activated. A Backup node shouldn't have any clients on it until the server is active.
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4. Re: HA Failover in shared-store configuration
johncprout Jun 4, 2010 6:45 PM (in response to clebert.suconic)What is the client in my scenario? There won't be any Producers, because no requests will be sent to the backup node. There will be a Consumer Client on the Backup node, which should process any messages remaining in the queue, but how does the Backup node know that the Live node has failed, so that messages should be delivered to the Consumer on the backup?
Thanks for your patience...
John
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5. Re: HA Failover in shared-store configuration
clebert.suconic Jun 4, 2010 7:12 PM (in response to johncprout)Client = Any connection to that server.
Client = Producer | Consumer.. it doesn't matter.
As soon as you connect a consumer to the backup, the backup is already activated.
If you connect a consumer to the backup, you will have a split brain scenario. (We are improving HA in that sense to avoid split brains).
At the moment, you should't connect anything to the backup while the live still alive.
As soon as the clients connect to the backup (due to their failover code), the backup will be activated.