You can migrate multi-broker replication domains to data replication
domains. Any multi-broker domains that exist in your application server environment
were created with a previous version of WebSphere Application Server.
Before you begin
Determine if the application server configuration you are migrating:
- Uses an instance of data replication service in peer-to-peer mode or in
client/server mode.
Before you begin migrating a client/server mode replication
domain, consider if migrating your replication domains might cause a single
point of failure. Because you migrate the servers to the new type of replication
domain one at a time, you risk a single point of failure if there are 3 or
fewer application servers. Before migrating, configure at least 4 servers
that use multi-broker replication domains. Perform the following steps to
migrate the multi-broker domains to data replication domains:
Dynamic
cache replication domains use the peer-to-peer topology.
- Uses HTTP session memory-to-memory replication that is overloaded at the
application or web module level.
If the application server configuration
you are migrating uses HTTP session memory-to-memory replication that is overloaded
at the application or web module level, you must upgrade your deployment manager
to the current version of WebSphere Application Server before you start the
migration process.
About this task
For HTTP session affinity to continue working
correctly when migrating V5.x application servers to V6.0 application servers,
you must upgrade all of the Web server plug-ins for WebSphere Application
Server to the latest version before upgrading the application servers that
perform replication.
After you upgrade your deployment manager to the
latest version of WebSphere Application Server, you can only create data replication
domains. Any multi-broker domains that you created with a previous release
of WebSphere Application Server are still functional, however, you cannot
use the administrative console to create new multi-broker domains or replicators.
The
different versions of application servers cannot communicate with each other.
When migrating your servers to the current version of WebSphere Application
Server, keep at least two application servers running on the previous version
so that replication remains functional.
Make sure that all of your application
servers that are using this multi-broker domain have been migrated to the
current version of WebSphere Application Server before you start to migrate
any mulit-broker domains that exist in your configuration.
To migrate
the multi-broker domains that exist in your configuration:
Procedure
- Migrate two or more of your existing servers to the current version
of WebSphere Application Server. The remaining servers on the previous
version of WebSphere Application Server can still communicate with each other,
but not with the migrated servers. The migrated servers can also communicate
with each other.
- In the administrative console, create an empty data replication
domain. Click Environment > Replication domains > New to create an
empty data replication domain.
- Add two of your migrated servers to the new data replication domain.
For example, if you are migrated four servers, only add two of them
to the new replication domain.
- Configure the two servers as consumers of the replication domain.
Configuring the servers as consumers of the replication domain enables
them to use the new domain to share data.
- Add some of the clients to the new data replication domain.
Perform this step only if the application server configuration you
are migrating uses an instance of data replication service in client/server
mode.
- Configure these clients as consumers of the replication domain.
- Verify that the new data replication domain are successfully sharing
data.
Only the servers and clients that are added to the data
replication domain and are configured as consumers of this domain can use
the data replication domain functions.
- Add the rest of your migrated servers to the new data replication
domain.
When the servers can use the new data replication domain
to successfully share data, migrate the rest of the servers that are using
the multi-broker replication domain to the new data replication domain.
For
example, if you are migrated four servers, add the remaining two servers to
the new replication domain.
- Configure these servers as consumers of the replication domain.
- Add the rest of the clients to the new data replication domain.
Perform this step only if the application server configuration you
are migrating uses an instance of data replication service in client/server
mode.
- Configure these clients as consumers of the replication domain.
- Restart all of the application servers and clients.
- Delete the empty multi-broker replication domain.
What to do next
During this process, you might lose existing sessions. However, the
application remains active through the entire process, so users do not experience
down time during the migration. Create a new replication domain for each type
of consumer. For example, create one replication domain for the session manager
and another replication domain for dynamic cache.