Runtime migration uses migration procedures and tools to
migrate topology configuration, applications, and databases to the
new version of IBM® Business Process Manager. The
runtime migration process replicates the source production configuration
into the target environment. During the migration process, the target
production environment replaces the source production environment,
so that the two environments are never operated in parallel.
When to use runtime migration
The
runtime migration procedures and tools support both stand-alone and
network deployment environment migrations, as well as variants that
include migration to a remote system, migration while an operating
system is being upgraded to a supported version, and network deployment
variants to support full downtime migration windows and minimal downtime
migration windows.
Runtime migration is supported for migration
from the following products:
- IBM BPM
Advanced V7.5
or V7.5.1
- WebSphere® Process
Server V7.0.0.x
or V6.2.x
Use the runtime migration method in the following scenarios:
- You want to move your applications to the new version without
a dependency on the development tools and the development environment.
- You want to have your source production environment configuration
and applications automatically replicated in the target production
environment.
- You have long-running process or human task instances
that started in the source environment and need to complete in the
target environment.
- You have product data in queues or failed events in product databases
that were created in the source environment and need to survive the
migration and be managed in the target production environment.
- You can tolerate a production environment downtime window to perform
the migration.
Benefits
Runtime migration
provides the following benefits:
- No dependency on the development tools
- Source environment configuration is replicated in the target environment
- Source environment applications are migrated to the target environment
- Source environment application data is moved, using existing database
tables
- Process and human tasks can start in the source
environment and complete in the target environment
- Application instance data on queues and failed events in the source
environment can be handled post migration by the target environment
- Additional hardware and software resources not required to manage
another production environment
Costs
Runtime migration incurs
the following costs:
- Downtime is required when the target product environment assumes
the role of the source production environment
- Requires all applications on a node to be ready to migrate at
the same time
- New features are not enabled automatically and sometimes unavailable
without migrating the application artifacts using artifact migration
- Parallel production environment cannot be set up
- Test focus:
- End-to-end testing to validate migration process
- Regression testing and performance tuning
Risks
Runtime migration involves
the following risks:
- A rollback plan must be in place to handle a possible migration
failure. For more information, see Rolling back your environment.
- Existing user applications should continue to run in the new runtime
at the same level of function they had in the old runtime. In some
cases, however, there might be a change in code on which the application
depends, such as a JDK change, which might have a negative impact
on the unchanged application.
High-level tasks
Runtime migration
includes the following high-level tasks:
- Install the new product version.
- Back up all production profiles and databases.
- Migrate each source environment profile to the target environment.
- Migrate or upgrade the product databases.
- Migrate the product database data.
