Cluster maintenance
Maintain WebSphere Portal in a cluster typically means applying corrective services (fix packs and interim fixes) or updating the software release level on each node in the cluster. Instructions for applying corrective service to a WebSphere Portal cluster are provided with the corrective service package. Before applying any maintenance, it is always important to analyze any impact to end users and ensure that you are able to provide uninterrupted service (also referred to as 24x7 availability), even during the maintenance phase.
For the discussion in this section, we classify fixes as "minor" if they do not update the underlying WebSphere Portal databases or require version upgrades to other supporting software such as databases servers or IBM WAS. Most of the WebSphere Portal service packs are not considered minor and may require the use of a separate installation procedure to ensure 24x7 availability. If you have not implemented horizontal scaling in environment; for example, you have only vertical servers in cluster, any fix that requires a restart will result in temporary outage for end users. Existing 24x7 install procedures do not apply to these environments.
Minor fixes
All minor fixes to WebSphere Portal in a clustered environment can be deployed by simply applying the fix on each cluster node using the install instructions supplied with the fix. You do not need to remove the node from cluster to apply minor fixes; doing so may result in the inability to add the node back to the cluster. When applying minor fixes that might update previously deployed enterprise applications, be sure to turn off the auto-synchronization feature of the dmgr before applying the fix. After the fix is deployed on all cluster nodes, you can force a manual synchronization using the dmgr to ensure that all updates are synchronized on the nodes. You can then enable the auto-synchronization feature again.If the documentation associated with the minor fix requires that WebSphere Portal or WAS be restarted, be sure to apply the minor fix one node at a time. This will enable other nodes to continue to provide service to end users. However, if the fix requires an update to the WebSphere Portal databases, you might be required to stop the cluster before applying the fix. If this is the case, use a procedure that ensures 24x7 availability.
Service packs
There are multiple approaches to installing service packs into a WebSphere Portal clustered environment. The recommended approach uses multiple production clusters. Installing a service pack involves modifying the IP sprayer to remove a cluster from receiving user requests, which allows time to finish handling existing user sessions, and upgrading that cluster to install the service pack on all nodes. After verification testing assures that the upgraded cluster is operational, it can start receiving production traffic while the next cluster is taken offline and goes through the upgrade process. This approach preserves complete 24x7 availability during the upgrade process.A separate document is available which describes the process of installing WebSphere Portal service packs (fix packs) into an existing cluster while maintaining 24x7 availability. To briefly summarize this procedure, you remove a node or set of nodes from the flow of user traffic by configuring the IP sprayer and Web server. You then upgrade the node with the service packs. After upgrading is complete, you return the node or set of nodes to the flow of user traffic, while repeating the procedure with the next node or set of nodes. This process continues until you have upgraded all nodes in the cluster.
While the upgrade process is taking place, some portlets may become temporarily unavailable because of updates to the shared database, which are incompatible with the previous version of the portlet. This can introduce functional limitations to the 24x7 availability when using this process.
Parent
Cluster considerations
Submitted by Megan Crouch on Aug 2, 2011 12:27:58 PM Re: Cluster maintenance
Michal,
This is a generic document about cluster maintenance. The specific document about installing the service pack in a 24x7 environment would be available where you download the service pack. If you need help locating the specific service pack instructions, please let me know what version you require and I can provide that link.
Megan Submitted by Michal Grabarczyk on Jul 28, 2011 7:42:35 AM
Re: Cluster maintenance
would be nice to put a refference to the document "A separate document is available which describes the process of installing WebSphere Portal service packs (fix packs) into an existing cluster while maintaining 24x7 availability. " because can't find it in Portal docs. Submitted by Michal Grabarczyk on Jul 28, 2011 7:18:11 AM
Re: Cluster maintenance
would be nice to put a refference to the document "A separate document is available which describes the process of installing WebSphere Portal service packs (fix packs) into an existing cluster while maintaining 24x7 availability. " because can't find it in Portal docs.