You can move the transaction logs for an application server
to another server.
About this task
The following steps explain how to move transaction logs
from one application server to another.
Note: The transaction service
does not allow transaction logs to be moved from one server to another
in a high availability (HA) environment. In such scenarios, WebSphere® Application Server
dynamically controls which server is assigned ownership of the recovery
logs. For this reason, the following steps are not applicable when
the
Enable failover of transaction log recovery option has been set
on the administrative console.
For more information see the Transactional high availability topic and its related topics.
Procedure
- Move all the transaction log files for the application
server.
The transaction log directory for each server contains
a number of files and subdirectories. When moving transaction logs
from one server to another you must move all of the files and subdirectories
together as a single unit; otherwise recovery might not complete resulting
in data inconsistency.
- Perform one of the following steps, depending on your server configuration:
- Optional: For a server configuration where there are no distributed
transactions, move the transaction logs to any server that has access to the same resource
managers.
For a single server or network-deployed server configuration where it is known
there are no distributed transactions present in the logs, the transaction logs can be moved to any
server (on any node) that has access to the same resource managers as the original server. For
example, the server needs communication and valid security access to databases or message
queues.
If the
server is in a different cell from the original server, you must ensure that there is a Java
Authentication and Authorization Service (JAAS) alias available to the server that was used by the
original server for accessing XA resources. In this case you should use wsadmin to construct the
aliases, because if you use the administrative console to create the alias, then the node name gets
prefixed to the alias.
All the transaction log files for the original server must be moved to
a directory accessible by the new server. This can be accomplished by either renaming the
transaction log directory or copying all the contents to the new server transaction log directory
before starting the new server.
- Optional: For a network-deployed server configuration where distributed
transactions must be recovered, move the transaction logs to a new server that has the same server
name, the same host name, and access to the same resource managers as the original
server.
Information about each server that is involved in a distributed transaction is
stored in the transaction logs. This information includes the server name and the host name of the
machine on which the server is running. During recovery, the servers that are involved in the
recovery of a distributed transaction use this stored information to contact each other. Therefore,
if a server fails and the logs must be recovered on a new server, that new server must have the same
server name and host name as the original server. The new server must also have the same access to
the same resource managers, databases, and message queues, as the original server.
Note: All servers within a cell must have unique names.
Note: To complete transaction recovery, the application server uses the resource manager
configuration information in the transaction logs. However, for the application server to continue
to do new work with the same resource managers, the server must have an appropriate resource manager
configuration (as for the original server).