On 05/12/11 09:29, Tom Mueller wrote:
> Before considering the comments below, please be aware that GlassFish
> does not currently support or document any failover scenarios for the
> DAS. So by doing this, you are experimenting with an unsupported
> configuration.
That is true for the shared storage approach described in the original
posting. We did test and document the scenario where a DAS is migrated
to a new host by using domain backups performed by the backup-domain
command (or automatic, scheduled backups supported via features
available in the Oracle GlassFish Server).
See:
http://download.oracle.com/docs/cd/E18930_01/html/821-2416/gglri.html#gglri
for the details of how to perform this migration.
Additionally, available in the Oracle GlassFish Server product we
provide the update-admin-server-coordinates command which can be used to
update the das.properties on the nodes in the cluster. If you are
using GlassFish Server Open Source Edition then this command will not be
available and you will have to manually update the das.properties on the
nodes impacted by the DAS location change.
Chris
>
> The das.properties file in the nodes/nodename/agent/config directory is
> only used by an instance to find a DAS when either it is being created
> for the first time, or when it is synchronizing during startup. The
> asadmin list-instances command doesn't use das.properties at all. The
> asadmin command can be executed from any remote client, whether it is
> hosting nodes or not. So the --host and --port arguments to the asadmin
> command specify the DAS on which to execute the command. When asadmin is
> run on the same host as the where the DAS is running, then the default
> values for those options (localhost and 4848) work, so the connection to
> the DAS is successful.
>
> I'm not aware of other references to the DAS within instances other than
> the das.properties file. It would be a pleasant surprise if DAS failover
> was actually that easy though.
>
> Tom
>