File stores

File stores enable messaging engines to preserve operating information and to persist those objects that messaging engines need for recovery in the event of a failure, using a file system.

A file store is a type of message store that directly uses files in a file system through the operating system. File store mechanisms split data storage into three levels: the log file, permanent store files, and temporary store files.

Figure 1. The relationship between a messaging engine and its file store.A messaging engine uses a JDBC data source to manage the interaction with a data store, which is held in a database
Log file
This file contains information about currently active transactions, and data that has not yet been written to a store file. The log file has a fixed size and does not expand as it is used.
Permanent store file
This file contains permanent data that are retained beyond a restart of the messaging engine, such as persistent messages and information about the storage and transmission of persistent messages.
Temporary store file
This file contains temporary data that are not retained beyond a restart of the messaging engine, such as nonpersistent messages that have been spilled to the file store to release memory from the JVM heap. The temporary store file is emptied when the messaging engine starts.

You can configure where the file store files are placed. By default, the file store uses a subdirectory beneath the ${USER_INSTALL_ROOT}/filestores directory. The file store directory contains three files, logDirectory, permanentstoreDirectory and temporaryStoreDirectory.




Subtopics
File store configuration attributes
Related concepts
Learning about file stores
Concept topic    

Terms of Use | Feedback

Last updated: Feb 19, 2011 5:25:36 AM CST
http://www14.software.ibm.com/webapp/wsbroker/redirect?version=v610web&product=was-nd-mp&topic=cjm1410
File name: cjm1410_.html