Define the desired cache configuration. There are several cache options to choose from. The various types of caches are explained here:

This configuration is not recommended. Without a cache Imago is required to generate complete transforms for each request. A well-tuned cache can significantly increase performance.

cache=org.xenei.util.cache.NoCache

Defines a cache that does nothing. It always accepts entries and never has anything cached.

Imago is shipped with the Memory Cache enabled.

cache=org.xenei.util.cache.memcache.MemoryCache

Specifies the MemoryCache as the cache.

cache.cacheclass=java.util.HashMap

Specifies that the cache should use the standard HashMap to store data internally. Any class that implements java.util.Map may be used.

cache.reaper.maxage=30

The maximum age in minutes of a cache entry before it is considered stale and removed.

cache.reaper.period=45

The period in minutes between sweeps of the cache for stale objects. This number should be larger than the maxage parameter.

cache.reaper.priority=1

The thread priority that the reaper will run with. If this is not set then the priority of the scheduler will be used.

cache.mem.min=1

The minimum free heap in MBs. This is the number of MBs required to be free when the cache is operating. If the free memory drops below this number the cache attempts an emergency clean of stale objects until the minimum free memory is achieved or the cache is disabled.

cache.mem.max=4

This is the maximum memory used by the application. It is not possible to differentiate between cache and non-cache items. If this limit is exceeded then an emergency clean of stale objects is attempted.

cache.lock.maxage=10

The maximum age of a cache lock in seconds. If a lock exceeds this age it is assumed to be abandoned and may be broken.

cache.lock.wait.count=5

The maximum number of times a thread should wait for a cache lock before giving up and proceeding to rebuild the object. If this is set too low the cache will build unnecessary objects, if too high the system will slow down waiting for locks when it could rebuild the object faster.

cache.lock.wait.time=100

The number of timer ticks in milliseconds the thread should wait between attempts to get a cache lock.

The DBCache utilizes a database. This can make it easy for multiple Imago servers to synchronize their caches. This can be particularly useful if Imago is being run in a clustered environment.

cache=org.xenei.util.cache.dbcache.DBCache

Use the DBCache.

cache.driver=com.mysql.jdbc.Driver

The JDBC driver to use. This must be a driver and database supported by LDBC.

cache.url=jdbc:mysql://db.xenei.org/imago

The URL for the database.

cache.user=imago

The user ID for the database.

cache.password=imago

The password for the database.

cache.reaper.period=15

The period in hours between sweeps of the cache for expired objects. In the DB cache an object is expired if it has changed. The reaper reads and validates every object in the table.

cache.reaper.priority=1

The thread priority the reaper will run with. If this is not set the priority of the scheduler will be used.

cache.lock.maxage=10

The maximum age of a cache lock in seconds. If a lock exceeds this age it is assumed to be abandoned and may be broken.

cache.lock.wait.count=5

The maximum number of times a thread should wait for a cache lock before giving up and proceeding to rebuild the object. If this is set too low the cache will build unnecessary objects, if set too high the system will slow down waiting for locks when it could rebuild the object faster.

cache.lock.wait.time=100

The number of timer ticks in milliseconds the thread should wait between attempts to get a cache lock.

The slow cache does not perform caching itself. It is used to wrap a slower caching implementation. For example a remote database cache may be too slow for regular operation but by wrapping it in a slow cache there is some speed improvement.

cache=org.xenei.util.cache.slowcache.SlowCache

Use the slow cache wrapper.

cache.wraps=org.xenei.util.cache.dbcache.DBCache

Define a wrapping of a database cache.

cache.wraps.driver=com.mysql.jdbc.Driver

cache.wraps.url=jdbc:mysql://db.xenei.org/imago

cache.wraps.user=imago

cache.wraps.password=imago

cache.wraps.reaper.period=15

cache.wraps.reaper.priority=1

cache.wraps.lock.maxage=10

cache.wraps.lock.wait.count=5

cache.wraps.lock.wait.time=100

The DB cache options.

The Xenei Cache is a two-level cache mechanism. This is particularly useful if you want to have a shallow cache for frequently used objects and a deeper cache for less frequently used objects, such as an in-memory cache backed by a database cache.

cache=org.xenei.util.cache.xeneicache.XeneiCache

Use the Xenei Cache.

cache.synchronizedlocks=false

Synchronized locks requires that both level1 and level2 caches be locked before a lock is returned. Otherwise the first level lock is tried and if it succeeds the second level is tried; regardless of the result of the second level lock the lock is returned.

cache.level1=org.xenei.util.cache.memcache.MemoryCache

Level 1 uses the memory cache.

cache.level1.cacheclass=java.util.HashMap

cache.level1.reaper.maxage=30

cache.level1.reaper.period=45

cache.level1.reaper.priority=1

cache.level1.mem.min=1

cache.level1.mem.max=4

cache.level1.lock.maxage=10

cache.level1.lock.wait.count=5

cache.level1.lock.wait.time=100

The memory cache definition.

cache.level2=org.xenei.util.cache.slowcache.SlowCache

Level 2 uses the slow cache wrapper.

cache.level2.wraps=org.xenei.util.cache.dbcache.DBCache

It is wrapping a database cache.

cache.level2.wraps.driver=com.mysql.jdbc.Driver

cache.level2.wraps.url=jdbc:mysql://db.xenei.org/imago

cache.level2.wraps.user=imago

cache.level2.wraps.password=imago

cache.level2.wraps.reaper.period=15

cache.level2.wraps.reaper.priority=1

cache.level2.wraps.lock.maxage=10

cache.level2.wraps.lock.wait.count=5

cache.level2.wraps.lock.wait.time=100

The DB cache options.