For manual application rollout, workload routing is controlled
by stopping the application server on which the cluster member being updated
resides. This results in a quiesce of that server. All existing requests already
in the server are allowed to complete, but no new requests are accepted. Both
the sysplex distributor and the WebSphere Application Server Web server plug-in
routes work away from the quiescing server. After all work has completed,
you start the application update process on this server.
Before you begin
Determine which application servers are hosting the cluster members
that need updating.
About this task
If you have a high availability application whose updates you want
to manually control you can use this process or you can use the MVS Modify
command to
pause the listeners for
the affected application servers.
To manually control application rollout
and workload routing in a high availability environment:
Procedure
- Disable all forms of automatic synchronization, across all nodes
in the cell and save the changes. Perform one of the following
processes to complete this step:
- In the administrative console:
- Click System administration > Node agents > node_agent_name > File
Synchronization Service.
- Unselect the Automatic Synchronization and Startup Synchronization options.
- Select the Synchronize changes with nodes option.
- Click Save.
- Use wsadmin scripting to specify the following commands and then restart
all affected node agents:
set node NODE
set na_id [$AdminConfig getid /Node:$node/Server:nodeagent/]
set syncServ [$AdminConfig list ConfigSynchronizationService $na_id]
$AdminConfig modify $syncServ {{autoSynchEnabled false}}
$AdminConfig modify $syncServ {{synchOnServerStartup false}}
$AdminConfig save
set nodeSync [$AdminControl completeObjectName type=NodeSync,node=$node,*]
$AdminControl invoke $nodeSync sync
Important: For a production
environment, it is reasonable to always run the node agent with automatic
synchronization disabled. However, it is advisable for startup synchronization
to be enabled for the node agent so that it can acquire configuration updates
that occur when the node agent is down. Startup Synchronization can be left
enabled provided you can ensure that you will not restart the node agent manually,
through automation, or through automatic restart manager during the application
update process.
- Update the application in the master configuration repository on
the deployment manager server. Perform one of the following processes
to complete this step:
- In the administrative console:
- Click Applications > Enterprise Applications.
- Select the application you want to update.
- Complete the application update process.
- Save your changes to the master configuration. DO NOT select the Synchronize
changes with nodes option .
- Use wsadmin scripting to issue the following command:
set app_loc /path/to/app
set app_options {application options ie: -appname app}
set options [list -update] lappend options $app_options
$AdminApp install $app_loc $options
$AdminConfig save
At this point, you have the updated the version
of your application (App v2 in the following figure) in your Master Configuration.
However, the original version of your application (App v1 in the following
figure) is still running in the cluster that has Cluster members on LPAR1
and LPAR2.
Figure 1. Install application
update.
This figure illustrates the first stage of an application
update in a high availability environment.
- Stop the Application Server on LPAR1 and manually synchronize the
node to the updated version of the application. This step may take
time to complete because the server must wait for all currently assigned work
items to complete before shutting down.
Perform one of the following processes
to complete this step:
- Synchronize the node. Perform one of the following processes
to complete this step:
As illustrated in the following figure, the updated version of the
application (App v2) now resides in the node on LPAR1.
Figure 2. Update the node on LPAR1.
This figure illustrates
the first stage of an application update in a high availability environment
with two LPARs.
- Restart the server on LPAR1. Perform one of the following
processes to complete this step:
- In the administrative console:
- Click Servers > Application servers.
- Select the server you want to start, and then click START.
- Use wsadmin scripting to issue the following commands:
set node NODE
set server SERVER
$AdminControl startServer $server $node
- Issue the following command from the MVS Console:
START procname,JOBNAME=server_short_name.ENV=cell_short_name.node_short_name.server_short_name
For example:START BBO6ACR,JOBNAME=BBOS001,ENV=PLEX1.SY1.BBOS001
When this server comes back up, it will be running the new version of
the application (App v2), Figure 3. Restart
the server on LPAR1.
This figure illustrates the completion of
the first stage of an application update in a high availability environment.

- With the new version of the application running on LPAR1, repeat
the preceding three steps on the other LPARs in the cluster to update them
with the new version of the application. The following figure illustrates
what your configuration will look like in a two LPAR cluster.
Figure 4. Update the node on LPAR2.
This figure
illustrates the second stage of an application update in a high availability
environment.
Results
The application update process is complete when the new version
of the application is running on all of the cluster members in the cluster.
The following figure illustrates what a two LPAR cluster will look like after
you restart the server on LPAR2.
Figure 5. Restart
server on LPAR2.
This figure illustrates what a two LPAR cluster
will look like after you restart the server on LPAR2.