Managing replication in your cluster
Replication is a service provided by IBM® WebSphere® Application Server that transfers data, objects, or events among application servers. Data replication can be used to make data for session manager, dynamic cache, and stateful session beans available across many application servers in a cluster.
About this task
Note: By
default, the IBM WebSphere Portal cluster
scripts enable dynamic caching for each cluster member. The replication
type is set to NOT SHARED.
- Dynamic caching
- Data replication service (DRS) is the internal WebSphere Application
Server component that
replicates data among application servers. There are several types
of data replication, and WebSphere Portal can
use data replication for dynamic caching and for memory-to-memory
replication of session data. Enabling data replication for dynamic
caching in a cluster environment is necessary to maintain data integrity
between multiple WebSphere Portal nodes
in the cluster. Replication also helps improve performance by generating
data once and then replicating it to other servers in the cluster.
Table 1. Links to information about dynamic cache service settings by operating system Operating system Additional information AIX® Linux Solaris Windows Dynamic cache service settings DB2 for z/OS tip: If you use the IBM DB2 Universal Database™ for z/OS® JDBC type 2 driver you must set the JDBC driver custom property fullyMaterializeLobData to false. See Data sources for information.IBM i Dynamic cache service settings DB2 for z/OS tip: If you use the IBM DB2 Universal Database for z/OS JDBC type 2 driver you must set the JDBC driver custom property fullyMaterializeLobData to false. See Data sources for information.z/OS Dynamic cache service settings DB2 for z/OS tip: If you use the IBM DB2 Universal Database for z/OS JDBC type 2 driver you must set the JDBC driver custom property fullyMaterializeLobData to false. See Data sources for information. - Distributed sessions
- WebSphere Portal can
use the WebSphere Application
Server capabilities
to support HTTP session failover, which enables one node in a cluster
to access information from the existing HTTP session in a failure
in the cluster node originally handling that session. This capability
is referred to as distributed sessions. WebSphere Application
Server provides two techniques
that can be used for distributed sessions, either of which can be
used in a WebSphere Portal cluster.
Distributed session support is not enabled by default, so you
must determine whether to provide this capability in your cluster,
and, if so, which of the two techniques you use: memory-to-memory
session replication and database session persistence.
Table 2. Links to information about distributed sessions by operating system Operating system Additional information AIX Linux Solaris Windows - For general information, see Session management support.
- For memory-to-memory information, see Memory-to-memory replication.
- For database session information, see Configuring for database session persistence.
IBM i - For general information, see Session management support.
- For memory-to-memory information, see Memory-to-memory replication.
- For database session information, see Configuring for database session persistence.
z/OS - For general information, see Session management support.
- For memory-to-memory information, see Memory-to-memory replication.
- For database session information, see Configuring for database session persistence.