Migrate servers from multi-broker replication domains to data replication domains
We can migrate multi-broker replication domains to data replication domains. Any multi-broker domains that exist in the application server environment were created with a previous version of the product.
Determine if the application server configuration we are migrating:
- Uses an instance of data replication service in peer-to-peer mode or in client/server mode.
Before beginning migrating a client/server mode replication domain, consider if migrating your replication domains might cause a single point of failure. Because we 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 we are migrating uses HTTP session memory-to-memory replication that is overloaded at the application or web module level, we must upgrade the deployment manager to the current version of the product before starting the migration process.
After we upgrade the deployment manager to the latest version of the product, we can only create data replication domains. Any multi-broker domains that we created with a previous version of the product are still functional, however, we 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 the servers to the current version of the product, keep at least two application servers running on the previous version so that replication remains functional.
Make sure that all of the application servers that are using this multi-broker domain have been migrated to the current version of the product before starting to migrate any multi-broker domains that exist in the configuration.
To migrate the multi-broker domains that exist in the configuration:
Tasks
- Migrate two or more of our existing servers to the current version of the product. The remaining servers on the previous version of the product 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 our migrated servers to the new data replication domain.
For example, if we are migrated fthe servers, only add two of them to the new replication domain.
- Configure the two servers as consumers of the replication domain.
Configure 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 we 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 our 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 we are migrated fthe 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 we 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, we 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.
Subtopics
- Data replication domains
Data replication domains and multi-broker domains both perform the same function, which is to provide data replication between application servers in a cluster. Even though we can still configure existing multi-broker domains with the current version of the product, after we upgrade the deployment manager, we can only create data replication domains in the administrative console.
Related:
Data replication Memory-to-memory topology: Peer-to-peer function Replicating data across application servers in a cluster