Hi,
Please see the answers inline
glassfish_at_javadesktop.org wrote:
>I'm working through a plan to migrate our apps to Glassfish and am planning on using a clustered profile. I have a couple questions about clusters in Glassfish and how the failover works in a cluster. From what I understand, if an instance of a cluster goes down the app will failover into another instance (to set this up do I need to enable and configure the load balancing in Glassfish?).
>
Yes, your understanding is correct
Please check the following blog for details
http://blogs.sun.com/quality/entry/glassfish_for_enterprise
>But what happens if the DAS goes down? Will all apps become unavailable? If so, is there a way to failover when the DAS goes down?
>
>
For this question, Nazrul's blog
<
http://blogs.sun.com/nazrul/entry/under_the_hood_of_glassfish> has
answer, sinppet is here
*Q: /Is there a way to backup/clone DAS so that it is not a single point
of failure for management?/*
/DAS/ has no role in application runtime functionality. So, when /DAS/
is un-available, the cluster will continue to run. You may use /%asadmin
backup-domain
<
http://docs.sun.com/app/docs/doc/819-4736/6n6s9pj18?a=view>/ command to
create a backup of /DAS/. After that, please backup the zip from
/backup-domain/ command in a highly available storage. When /if /DAS/'s
machine crashes, you may use /%asadmin restore-domain
<
http://docs.sun.com/app/docs/doc/819-4736/6n6s9pj7k?a=view>/ command
with the previously backed-up zip to restore the domain in another
machine. During /DAS/'s startup, it will ping all the /node agents/ to
notify the new co-ordinates of /DAS/. Solaris [Sun] Cluster
<
http://www.sun.com/software/solaris/cluster/index.xml> has support for
Sun Java System Application Server
<
http://www.sun.com/software/products/appsrvr/index.xml>. You may use it
to provide automatic failover. Refer to this documentation
<
http://docs.sun.com/app/docs/doc/817-7000/6mmbndqgp?a=view> for more
details.
Thanks,
Gopal
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--
<http://blogs.sun.com/quality> * Gopal Jorapur*
Software Engineer
Blog Page <http://blogs.sun.com/quality>
GlassFish Quality Community
<http://glassfish.dev.java.net/quality/portal/index.html>
Sun Java Application Server
<http://www.sun.com/software/products/appsrvr/index.jsp>
Sun Microsystems, Inc.
Phone x34452
Email Gopal.Jorapur_at_Sun.COM <mailto:gopal.jorapur_at_sun.com>