Using memcached as a two-level distributed cache in Hibernate

Transferred from: http://www.blogjava.net/xmatthew/archive/2008/08/20/223293.html hibernate-memcached--using memcached as a level two distributed cache in hibernate

Today on the Internet to see a use memcached as hibernate two level distributed cache, feel very interested, is trying to use, feel good, recommend to everyone to see.

Official website: http://code.google.com/p/hibernate-memcached/
Currently the latest version is 1.0, supporting Hibernate3.3.

Here are the specific ways to use it:
The class libraries that hibernate-memcached need to support are as follows:

• Hibernate-memcached-<version>.jar
• Memcached-2.1.jar
• Spy-2.4.jar
• Commons-codec 1.3
• Slf4j-1.5.0.jar If your project is using log4j, you can use the Slf4j-log4j12-1.5.0.jar

The configuration method is as follows:

Configure hibernate to use the cache to provide classes

Hibernate.cache.provider_class

Com.googlecode.hibernate.memcached.MemcachedCacheProvider

Set query cache to open

Hibernate.cache.use_query_cache

True

Some other parameter setting instructions:

Property	Default	Description
Hibernate.memcached.servers	localhost:11211	memcached service address, multiple spaces separated Format Host:port
Hibernate.memcached.cacheTimeSeconds	300	Cache expiration time, in seconds
Hibernate.memcached.keyStrategy	Hashcodekeystrategy	Cache key Generation Storage Hashcode algorithm
Hibernate.memcached.readBufferSize	Defaultconnectionfactory.default_read_buffer_size	Read data buffer size from server
Hibernate.memcached.operationQueueLength	Defaultconnectionfactory.default_op_queue_len	Maximum length of the operation queue returned by this connection factory
Hibernate.memcached.operationTimeout	Defaultconnectionfactory.default_operation_timeout	Operation Time-out setting
Hibernate.memcached.hashAlgorithm	Hashalgorithm.ketama_hash	The hash hash algorithm used when caching data to the server is added. When Hibernate-memcached is set to the Ketama_hash algorithm, note: The default client API uses Hashalgorithm.native_hash
hibernate.memcached.clearSupported	False	The Memcachedcache.clear () method is supported to empty the cache. It is not recommended to open.

Configuration examples (this article takes Hibernate3.3-entitymanager as an example)
Configuring the Persistence.xml File

<?xml version= "1.0" encoding= "UTF-8"?>
<persistence xmlns= "Http://java.sun.com/xml/ns/persistence" "target=" _new ">http://java.sun.com/xml/ns/ Persistence "xmlns:xsi=" Http://www.w3.org/2001/XMLSchema-instance "xsi:schemalocation=" http://java.sun.com/xml/ Ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd "version=" 1.0 ">

<persistence-unit name= "Entitymanager" transaction-type= "resource_local" >
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>java:comp/env/jdbc/qualitydb</jta-data-source>

<properties>
<property name= "Hibernate.dialect" value= "Org.hibernate.dialect.PostgreSQLDialect"/>
<property name= "Hibernate.max_fetch_depth" value= "3"/>
<property name= "Hibernate.show_sql" value= "true"/>


<property name= "Hibernate.cache.region_prefix" value= "Quality.cache.ehcache"/>
<property name= "Hibernate.cache.use_second_level_cache" value= "true"/>
<property name= "Hibernate.cache.use_structured_entries" value= "true"/>
<property name= "Hibernate.cache.use_query_cache" value= "true"/>
<property name= "Hibernate.cache.provider_class" value= " Com.googlecode.hibernate.memcached.MemcachedCacheProvider "/>
<property name= "Hibernate.memcached.servers" value= "localhost:11211"/>

</properties>

</persistence-unit>

</persistence>

When you start, you are prompted as follows:
2008-08-28 17:10:08,312 jclloggeradapter.java265 INFO--Starting memcachedclient ...
2008-08-28 17:10:08.718 INFO net.spy.memcached.MemcachedConnection:Added {QA sa=localhost/127.0.0.1:11211, #Rops = 0, # Wops=0, #iq =0, Toprop=null, Topwop=null, towrite=0, interested=0} to connect queue
2008-08-28 17:10:08.750 INFO net.spy.memcached.MemcachedConnection:Connection state changed for [email protected]

Indicates that our first step configuration has succeeded, and next, configure the entity that needs to be cached

1 @Entity
2 @Cache (usage = cacheconcurrencystrategy.read_write)//setting requires caching
3 public class Student {
4
5 @Id
6 @Column (LENGTH=32)
7 Private String ID;
8
9 @Column (LENGTH=20)
Ten private string name;
11
@OneToMany
@Cache (usage = cacheconcurrencystrategy.read_write)
+ Private set<book> books;
15
16}

Ok, the configuration is now complete.