WebSphere eXtreme Scale Best Practices for Operation and Management

182 WebSphere eXtreme Scale Best Practices for Operation and Management

7.6.1 Overview

When applying maintenance to WebSphere eXtreme Scale, it is important to realize that

three logical components are involved. To avoid interrupting service, you

must apply

maintenance in the following order:

1. Catalog servers

2. Containers

3. Clients

The catalog servers must always be at the highest software level. Avoid situations where

several of the container servers (or clients) are interacting with back-level catalog servers.

Topologies where catalog servers and containers are deployed on separate machines, are

optimal for maintenance purposes. Maintenance can be applied to catalog servers without

impacting the containers, because each has its own binary installation on its own machine.

7.6.2 Procedures

See the product documentation for a detailed description of how to apply product updates to

the WebSphere eXtreme Scale environment without interrupting service:

http://publib.boulder.ibm.com/infocenter/wxsinfo/v7r1/topic/com.ibm.websphere.extr

emescale.admin.doc/txsupdateserv.html

Upgrade procedures in an WebSphere eXtreme Scale environment include the following

tasks:

򐂰 Operating system (OS) upgrade

򐂰 WebSphere eXtreme Scale product upgrade

򐂰 Applying a patch to an application, which is a grid client, in two forms:

– The patch includes no change to the objects that are stored in the grid (or logic

changes only, no data changed).

– The patch includes changes to the objects that are stored in the grid.

Service scenarios and their recommended procedures

Next, we describe the various service scenarios. For each scenario, we describe the

recommended procedure, referring to the typical pre-WebSphere eXtreme Scale procedure

Alternative: Although not recommended, it is possible to use a topology where catalog

servers and containers are colocated. But, applying maintenance to the catalog server

without impacting the container becomes more difficult. All running components that use

the same set of binaries have to be stopped, because they each hold locks on the jars and

libraries.

In this case, consider using two separate WebSphere eXtreme Scale installations. This

design allows both the catalog server and the container to use their own sets of binaries.

Applying maintenance to one no longer affects the other.

Using application-specific properties files: The procedures in this section make use of

application-specific properties files. Specifically, all applications have their grid names

passed to them in a properties file that can be edited, if necessary. This method is perfectly

acceptable.