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<document>
	<properties>
		<title>MySQL Disk Cache Configuration</title>
		<author email="asmuts@apache.org">Aaron Smuts</author>
	</properties>

	<body>
		<section name="MySQL Disk Auxiliary Cache Configuration">

			<p>
				The MySQL Disk Cache uses all of the JDBC Disk Cache
				properties. It adds a few of its own. The following
				properties only apply to the MySQL Disk Cache plugin.
			</p>

			<subsection name="MySQL Disk Configuration Properties">
				<table>
					<tr>
						<th>Property</th>
						<th>Description</th>
						<th>Required</th>
						<th>Default Value</th>
					</tr>
					<tr>
						<td>optimizationSchedule</td>
						<td>
							For now this is a simple comma delimited
							list of HH:MM:SS times to optimize the
							table. If none is supplied, then no
							optimizations will be performed.

							In the future we can add a cron like
							scheduling system. This was created to meet
							a pressing need to optimize fragmented
							MyISAM tables. When the table becomes
							fragmented, it starts to take a long time to
							run the shrinker that deletes expired
							elements.

							Setting the value to "03:01,15:00" will
							cause the optimizer to run at 3 am and at 3
							pm.
						</td>
						<td>N</td>
						<td>null</td>
					</tr>

					<tr>
						<td>balkDuringOptimization</td>
						<td>
							If this is true, then when JCS is optimizing
							the table it will return null from get
							requests and do nothing for put requests.

							If you are using the remote cache and have a
							failover server configured in a remote cache
							cluster, and you allow clustered gets, the
							primary server will act as a proxy to the
							failover. This way, optimization should have
							no impact for clients of the remote cache.
						</td>
						<td>N</td>
						<td>true</td>
					</tr>

				</table>
			</subsection>

			<subsection name="Example Configuration">
				<source>
					<![CDATA[
##############################################################
################## AUXILIARY CACHES AVAILABLE ################
# MYSQL disk cache
jcs.auxiliary.MYSQL=org.apache.commons.jcs.auxiliary.disk.jdbc.mysql.MySQLDiskCacheFactory
jcs.auxiliary.MYSQL.attributes=org.apache.commons.jcs.auxiliary.disk.jdbc.mysql.MySQLDiskCacheAttributes
jcs.auxiliary.MYSQL.attributes.userName=sa
jcs.auxiliary.MYSQL.attributes.password=
jcs.auxiliary.MYSQL.attributes.url=jdbc:hsqldb:target/cache_hsql_db
jcs.auxiliary.MYSQL.attributes.driverClassName=org.hsqldb.jdbcDriver
jcs.auxiliary.MYSQL.attributes.tableName=JCS_STORE_MYSQL
jcs.auxiliary.MYSQL.attributes.testBeforeInsert=false
jcs.auxiliary.MYSQL.attributes.maxActive=15
jcs.auxiliary.MYSQL.attributes.allowRemoveAll=true
jcs.auxiliary.MYSQL.attributes.MaxPurgatorySize=10000000
jcs.auxiliary.MYSQL.attributes.optimizationSchedule=12:34:56,02:34:54
jcs.auxiliary.MYSQL.attributes.balkDuringOptimization=true
        ]]>
				</source>
			</subsection>

			<subsection name="MySQL Disk Event Queue Configuration">

				<table>
					<tr>
						<th>Property</th>
						<th>Description</th>
						<th>Required</th>
						<th>Default Value</th>
					</tr>
					<tr>
						<td>EventQueueType</td>
						<td>
							This should be either SINGLE or POOLED. By
							default the single style pool is used. The
							single style pool uses a single thread per
							event queue. That thread is killed whenever
							the queue is inactive for 30 seconds. Since
							the disk cache uses an event queue for every
							region, if you have many regions and they
							are all active, you will be using many
							threads. To limit the number of threads, you
							can configure the disk cache to use the
							pooled event queue. Using more threads than
							regions will not add any benefit for the
							indexed disk cache, since only one thread
							can read or write at a time for a single
							region.
						</td>
						<td>N</td>
						<td>SINGLE</td>
					</tr>
					<tr>
						<td>EventQueuePoolName</td>
						<td>
							This is the name of the pool to use. It is
							required if you choose the POOLED event
							queue type, otherwise it is ignored.
						</td>
						<td>Y</td>
						<td>n/a</td>
					</tr>
				</table>
			</subsection>

			<subsection
				name="Example Configuration Using Thread Pool">
				<source>
					<![CDATA[
##############################################################
################## AUXILIARY CACHES AVAILABLE ################
# MYSQL disk cache
jcs.auxiliary.MYSQL=org.apache.commons.jcs.auxiliary.disk.jdbc.mysql.MySQLDiskCacheFactory
jcs.auxiliary.MYSQL.attributes=org.apache.commons.jcs.auxiliary.disk.jdbc.mysql.MySQLDiskCacheAttributes
jcs.auxiliary.MYSQL.attributes.userName=sa
jcs.auxiliary.MYSQL.attributes.password=
jcs.auxiliary.MYSQL.attributes.url=jdbc:hsqldb:target/cache_hsql_db
jcs.auxiliary.MYSQL.attributes.driverClassName=org.hsqldb.jdbcDriver
jcs.auxiliary.MYSQL.attributes.tableName=JCS_STORE_MYSQL
jcs.auxiliary.MYSQL.attributes.testBeforeInsert=false
jcs.auxiliary.MYSQL.attributes.maxActive=15
jcs.auxiliary.MYSQL.attributes.allowRemoveAll=true
jcs.auxiliary.MYSQL.attributes.MaxPurgatorySize=10000000
jcs.auxiliary.MYSQL.attributes.optimizationSchedule=12:34:56,02:34:54
jcs.auxiliary.MYSQL.attributes.balkDuringOptimization=true
jcs.auxiliary.MYSQL.attributes.EventQueueType=POOLED
jcs.auxiliary.MYSQL.attributes.EventQueuePoolName=disk_cache_event_queue

##############################################################
################## OPTIONAL THREAD POOL CONFIGURATION #########
# Disk Cache pool
thread_pool.disk_cache_event_queue.useBoundary=false
thread_pool.disk_cache_event_queue.boundarySize=500
thread_pool.disk_cache_event_queue.maximumPoolSize=15
thread_pool.disk_cache_event_queue.minimumPoolSize=10
thread_pool.disk_cache_event_queue.keepAliveTime=3500
thread_pool.disk_cache_event_queue.whenBlockedPolicy=RUN
thread_pool.disk_cache_event_queue.startUpSize=10
        ]]>
				</source>
			</subsection>

		</section>
	</body>
</document>