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Problem(Abstract) |
Doing a ripple start/restarting a server in a cluster,
client applications sometimes fail with CORBA.OBJECT_NOT_EXIST error
message |
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Cause |
WorkLoad Manager will route to a server when it is up
based on it is connectivity. When a server starts up and connects to the
deployment manager and node agent then it is considered available, whether
or not the applications underneath are currently up.
The server itself is up and connected to the cell/cluster at the time the
request goes out, so the server itself is up and running, however, the
application/object that the request is destined for is not yet running.
WorkLoad Manager does not route based on application availability. It will
mark servers unavailable if the application on that server fails and not
route to them until it again comes up, but when it comes to starting up
the server, the request was simply issued before the server itself was
ready to handle that request. |
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Resolving the
problem |
If the user is intentionally stopping and starting the
servers, there is a method by which this failure could be avoided. If the
user were to write a script to use the Cluster MBean to set the configured
weight of the server to zero, shut down the server, start it up, and after
it is fully started (applications are started), then set the weight back
to whatever it was before. Using this method, WorkLoad Manager won't route
to the server with a weight of zero unless every available member of the
cluster has a weight of zero (so you need at least one other member up for
this to work).
NOTE:
This is currently working as designed, ie, users have control over when
the stop happens, and not if it is a failure or crash.
See links below to view the script samples for specific version applicable
both to Distributed and z/OS envirounment:
For version 6.0
http://publib.boulder.ibm.com/infocenter/wasinfo/v6r0/index.jsp?topic=/com.ibm.websphere.zseries.doc/info/zseries/ae/rjmx_proxyexamp.html
For version 5.1
http://publib.boulder.ibm.com/infocenter/wasinfo/v5r1//index.jsp?topic=/com.ibm.websphere.base.doc/info/welcome_base.html
For version 5.0
http://publib.boulder.ibm.com/infocenter/wasinfo/v5r0/index.jsp?topic=/com.ibm.websphere.base.doc/info/welcome_base.html |
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Cross Reference information |
Segment |
Product |
Component |
Platform |
Version |
Edition |
Application Servers |
Runtimes for Java Technology |
Java SDK |
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