Instead of stopping the application server, you can use the MVS console
Modify command to pause the listeners for that application server, perform
the application update, and then resume the listeners. If you use this technique,
you do not have to stop and then start the server to perform the application
update.
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, but you do not want to stop the affected servers, you
can use the MVS Modify command to pause the listener for each of these servers
and then update the application.
To pause the listeners and manually control
application rollout in a high availability environment:
Note:
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 node_agent_name > File Synchronization Service.
- Deselect 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
Note: 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 .
- 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.
- Pause the listener of the application server on LPAR1 and manually
synchronize the node to the updated version of the application. After
you pause the listener, wait for all work items currently assigned to the
server to complete, and then issue the following command from the MVS Console:
MODIFY short_server_name,PAUSELISTENERS
For
example, if the short name for the server you are pausing is BBOS001, issue
the following command:
MODIFY BBOS001,PAUSELISTENERS
- 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.
- Resume the listener of the application server on LPAR1. Issue
the following command from the MVS Console:
MODIFY short_server_name,RESUMELISTENERS
For
example, if the short name for the server you are pausing is BBOS001, issue
the following command:
MODIFY BBOS001,RESUMELISTENERS
- 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 3. 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 LPARs in the cluster.