Hibernate - Memcached

A library for using Memcached as a second level distributed cache in Hibernate.

Uses spymemcached client
Supports entity and query caching.

Maven dependency

To install it, you just need to add the following Maven dependency (check Versions for the right version for you):

<dependency>
    <groupId>com.github.mihaicostin</groupId>
    <artifactId>hibernate-l2-memcached</artifactId>
    <version>5.4.2.1</version>
</dependency>

https://mvnrepository.com/artifact/com.github.mihaicostin/hibernate-l2-memcached

Example config:

<property name="hibernate.cache.region.factory_class">com.mc.hibernate.memcached.MemcachedRegionFactory</property>
<property name="hibernate.memcached.operationTimeout">5000</property>
<property name="hibernate.memcached.connectionFactory">KetamaConnectionFactory</property>
<property name="hibernate.memcached.hashAlgorithm">FNV1_64_HASH</property>

If memcached authentication is required you can specify username and password:

<property name="hibernate.memcached.username">memcached-username</property>
<property name="hibernate.memcached.password">memcached-password</property>

If memcached are running on a remote server, e.g. on AWS ElastiCache, you can specify the connection URL:

<property name="hibernate.memcached.servers">cache.c3wd5k.cfg.euw1.cache.amazonaws.com:11211</property>

Configuration options

Targeting the memcached client (net.spy.memcached configurations)

Property	Default Value
hibernate.memcached.servers	localhost:11211
hibernate.memcached.operationQueueLength	(default provided by net.spy.memcached.DefaultConnectionFactory)
hibernate.memcached.readBufferSize	(default provided by net.spy.memcached.DefaultConnectionFactory)
hibernate.memcached.operationTimeout	(default provided by net.spy.memcached.DefaultConnectionFactory)
hibernate.memcached.hashAlgorithm	NATIVE_HASH
hibernate.memcached.connectionFactory	DefaultConnectionFactory
hibernate.memcached.daemonMode	false
hibernate.memcached.username	-
hibernate.memcached.password	-

Targeting the cache implementation (global or region specific)

Property	Default Value
hibernate.memcached.cacheTimeSeconds	300
hibernate.memcached.clearSupported	false
hibernate.memcached.memcacheClientFactory	com.mc.hibernate.memcached.spymemcached.SpyMemcacheClientFactory
hibernate.memcached.dogpilePrevention	false
hibernate.memcached.dogpilePrevention.expirationFactor	2
hibernate.memcached.keyStrategy	com.mc.hibernate.memcached.keystrategy.Sha1KeyStrategy

In order to specify a property for a specific region add the region name right after memcached. ex: hibernate.memcached.myregion.cacheTimeSeconds

Versions

Use the version compatible with your hibernate version (ex: Version 5.2.1.x is developed for and compatible with hibernate 5.2.1.Final)

Hibernate 6.2.x

v 6.2.1.0
- Added support for Hibernate 6.2.1.Final (PR by @wglasshusain). Note: This version requires Java 17

Hibernate 5.4.x

v 5.4.2.1
- Shutdown spymemcached client on SessionFactory.close (https://github.com/mihaicostin/hibernate-l2-memcached/commit/dc2ad3c0028916fb8b5d6c56094a9541b98c5a49 by @andrescmasmas)
v 5.4.2.0
- Fix for Issue #17
- tested with hibernate versions 5.3.3.Final - 5.4.2.Final

Hibernate 5.3.x

no support for hibernate 5.3.0 - 5.3.2
for hibernate 5.3.3 - 5.3.9 use v 5.4.2.0

Hibernate 5.2.x

v 5.2.17.0
- Fix for Issue #16
- hibernate-core dependency (as provided): 5.2.17.Final
v 5.2.10.0
- Add a new cache property hibernate.memcached.cacheLockTimeout (defaults to 60.000 ms)
- Update to latest spymemcached version
- hibernate-core dependency (as provided): 5.2.10.Final
v 5.2.7.1
- Fix for Issue #9
v 5.2.7.0
- Support Hibernate 5.2.7.Final (PR by @akhalikov )
- Update spymemcached to 2.12.2
- Tested with 5.2.7.Final - 5.2.10.Final
v 5.2.1.0
- Update spymemcached to the latest version: 2.12.1

Hibernate 5.1.x

v 5.1.5.1
- Fix for Issue #9
v 5.1.5.0
- Support for Hibernate 5.1.x (tested with 5.1.1.Final - 5.1.5.Final)

Hibernate 5.0.x

v 5.0.1.0
- Support for Hibernate 5.0.x

Hibernate 4.3.x

v 4.3.11.0
- Fix for Issue #9 (configure the cache with all available properties)

v 1.1.0

Memcached client now respects the region timeout property Issue #1

<property name="hibernate.memcached.REGION.cacheTimeSeconds">10</property>

v 1.0.0
- Compatible with hibernate 4.3.x

Known issues

SecondLevelCacheStatistics won't work with this adapter since it tries to get the cache content as a Map (and that's not easily done with memcached)
Cache region eviction won't actually evict the key, but invalidate them (see https://github.com/memcached/memcached/wiki/ProgrammingTricks#deleting-by-namespace)

Acknowledgements

Based on the work done on Hibernate-Memcached for hibernate 3.x
- https://github.com/raykrueger/hibernate-memcached
- https://github.com/kcarlson/hibernate-memcached

mihaicostin / hibernate-l2-memcached