Optional: To change
the directory in which transaction logs are written, type the full
path name of the directory in the Transaction log directory field.
You can check the current runtime value of Transaction
log directory by clicking the Runtime tab.When you use WebSphere Application
Server without high availability support, you do not need to set the
recovery log configuration for persistent services such as the transaction
service. The application server assumes a default location in the
appropriate profile directory. When high availability support is enabled,
this default might not be visible from all servers in the cluster
(for example, if the servers are in different profiles or physical
nodes.) Because of this behavior, configure the recovery log location
for each server in the cluster before enabling high availability.
Ensure that each server in a cluster has a unique transaction log
directory, so that multiple servers do not attempt to access the same
log file. Also, ensure that each server in a cluster can access the
transaction log directories of the other servers in the cluster.
In a high availability (HA)
environment, both the transaction log and the compensation log directory
for each server in a cluster must be unique.
Note: If
you change the transaction log directory, apply the change and restart
the application server as soon as possible, to minimize the risk of
problems occurring before the application server is restarted. For
example, if there is a problem and the server fails with in-flight
transactions, when the server restarts, it uses the new log directory
and cannot automatically resolve in-flight transactions that were
recorded in the old log directory.
You can also specify a
size for the transaction logs, as described in the following step.
Optional: To change the size of transaction
log files, modify the Transaction log directory field
to include a file size setting. Use one of the following formats,
where directory_name is the name of the transaction
log directory and file_size is the disk space allocation
for the transaction log files, specified in kilobytes (nK)
or megabytes (nM). The minimum transaction log
file size that you can specify is 64K. If you specify a value that
is less than 64K, or you do not specify a value for the file size,
the default value of 1M is used. ;file_size <!-- This format keeps the default directory -->
directory_name;file_size
dir://directory_name/directory_name;file_size
/directory_name/directory_name;file_size
For example, for a Windows system, the following entry
specifies that transaction log files are created in the directory
c:\tranlogs with
a size of 2 megabytes.
c:\tranlogs;2M
For a z/OS system, you might want to reduce the size
of the transaction logs to ensure that they do not exceed the maximum
amount of data space storage that is allocated for memory mappings.
This is set through the MAXMMAPAREA parameter.
In a non-production environment, you can turn
transaction logging off by entering ;0 in the Transaction
log directory field (do not enter a directory name). Do
not turn transaction logging off in a production environment because
this prevents recovery after a system failure, and therefore data
integrity cannot be guaranteed.
For
more information about transaction log sizes, see Managing transaction logging for optimum server availability.