http://www.bea.com/ns/weblogic/920/domain
element transaction-log-file-write-policy

Model

<transaction-log-file-write-policy>annonymous type derived from string</transaction-log-file-write-policy>

Disallowed substitutions (block)

none (extensions, restrictions and substitutions are allowed)

Substitution group exclusion (final)

none (extensions and restrictions are allowed)

Usage

Documentation

The policy that determines how transaction log file entries are written to disk. This policy can affect transaction performance. (Note: To be transactionally safe, the Direct-Write policy may require additional OS or environment changes on some Windows systems.)

WebLogic Server supports the following policies:

• Cache-Flush. Flushes operating system and on-disk caches after each write.

• Direct-Write. Tells the operating system to write directly to disk with each write. Direct-Write performs better than Cache-Flush and is available on Windows, HP-UX, and Solaris.

If Direct-Write is not supported on the host platform, the policy becomes Cache-Flush and a log message is printed.

Note: On Windows, unlike Solaris and HP, the "Direct-Write" policy may leave transaction data in the on-disk cache without writing it to disk immediately. This is not transactionally safe because a power failure can cause loss of on-disk cache data. For transactionally safe writes using "Direct-Write" on Windows, either disable all write caching for the disk (enabled by default), or use a disk with a battery-backed cache.

The on-disk cache for a hard-drive on Windows can be disabled through system administration: Control-Panel -> System -> Hardware-tab -> Device-Manager-button -> Disk-Drives -> name-of-drive -> Policies-tab -> "Enable write caching on the disk" check-box. Some file systems do not allow this value to be changed. For example, a RAID system that has a reliable cache.

Privileges: Read/Write

Default Value: Direct-Write

Redeploy or Restart required: Changes take effect after you redeploy the module or restart the server.

MBean Attribute: ServerMBean.TransactionLogFileWritePolicy

Fundamental Facets

equality, non-numeric, unbounded, unordered, countable infinite value space

White Space Processing

preserve

Enumeration Facet

"Cache-Flush", "Direct-Write"