Redis based Tomcat Session Manager
===

Stores session of Apache Tomcat in Redis and allows to distribute requests across a cluster of Tomcat servers. Implements non-sticky session management backed by Redis.  

Supports Apache Tomcat 6.x, 7.x, 8.x, 9.x

<sub>Please consider __[Redisson PRO](https://redisson.pro)__ version for advanced features and support by SLA.</sub>

Advantages
===

Current implementation differs from any other Redis based Tomcat Session Manager in terms of efficient storage and optimized writes. Each session attribute is written into Redis during each `HttpSession.setAttribute` invocation. While other solutions serialize whole session each time.

Usage
===

### 1. Add `RedissonSessionManager`

Add `RedissonSessionManager` into `tomcat/conf/context.xml`
   
   ```xml
<Manager className="org.redisson.tomcat.RedissonSessionManager"
	         configPath="${catalina.base}/redisson.conf" readMode="REDIS" updateMode="DEFAULT"/>
   ```
   `readMode` - read attributes mode. Two modes are available:
   * `MEMORY` - stores attributes into local Tomcat Session and Redis. Further Session updates propagated to local Tomcat Session using Redis-based events.
   * `REDIS` - stores attributes into Redis only.  Default mode.
   <br/>

   `updateMode` - attributes update mode. Two modes are available:
   * `DEFAULT` - session attributes are stored into Redis only through setAttribute method. Default mode.
   * `AFTER_REQUEST` - all session attributes are stored into Redis after each request.
   <br/>

   `configPath` - path to Redisson JSON or YAML config. See [configuration wiki page](https://github.com/redisson/redisson/wiki/2.-Configuration) for more details.

Each RedissonSessionManager created per Web Application and thus creates own Redisson instance. For multiple applications, using the same Redis setup, amount of Redisson instances could be reduced using JNDI registry:

1. Add shared redisson instance produced by `JndiRedissonFactory` into `tomcat/conf/server.xml` in `GlobalNamingResources` tag area:

```xml
  <GlobalNamingResources>
    <Resource name="bean/redisson" auth="Container"
              factory="org.redisson.JndiRedissonFactory"
              configPath="${catalina.base}/conf/redisson.yaml"/>
  </GlobalNamingResources>
```

2. Add `JndiRedissonSessionManager` with resource link to redisson instance into `tomcat/conf/context.xml`

```xml
    <ResourceLink name="bean/redisson"
                  global="bean/redisson"
		  type="org.redisson.api.RedissonClient" />

    <Manager className="org.redisson.tomcat.JndiRedissonSessionManager"
         readMode="REDIS"
         jndiName="bean/redisson" />
```

3. Package all classes used in session into separate jar and copy it to `tomcat/lib` directory.

**2** Copy two jars into `TOMCAT_BASE/lib` directory:
  
1. __For JDK 1.8+__  
      [redisson-all-3.9.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-all&v=3.9.1&e=jar)
  
      for Tomcat 6.x  
      [redisson-tomcat-6-3.9.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-tomcat-6&v=3.9.1&e=jar)  
      for Tomcat 7.x  
      [redisson-tomcat-7-3.9.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-tomcat-7&v=3.9.1&e=jar)  
      for Tomcat 8.x  
      [redisson-tomcat-8-3.9.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-tomcat-8&v=3.9.1&e=jar)  
      for Tomcat 9.x  
      [redisson-tomcat-9-3.9.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-tomcat-9&v=3.9.1&e=jar)  
  
2. __For JDK 1.6+__  
      [redisson-all-2.14.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-all&v=2.14.1&e=jar)
  
      for Tomcat 6.x  
      [redisson-tomcat-6-2.14.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-tomcat-6&v=2.14.1&e=jar)  
      for Tomcat 7.x  
      [redisson-tomcat-7-2.14.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-tomcat-7&v=2.14.1&e=jar)  
      for Tomcat 8.x  
      [redisson-tomcat-8-2.14.1.jar](https://repository.sonatype.org/service/local/artifact/maven/redirect?r=central-proxy&g=org.redisson&a=redisson-tomcat-8&v=2.14.1&e=jar)