Web Session Management

Tomcat Session

Redisson implements Redis or Valkey based Tomcat Session Manager. It stores session of Apache Tomcat in Redis or Valkey and allows to distribute requests across a cluster of Tomcat servers. Implements non-sticky session management backed by Redis.

Supports Apache Tomcat 7.x, 8.x, 9.x, 10.x

Usage:

1. Add session manager

Add RedissonSessionManager in global context - tomcat/conf/context.xml or per application context - tomcat/conf/server.xml

<Manager className="org.redisson.tomcat.RedissonSessionManager"
     configPath="${catalina.base}/redisson.conf" 
     readMode="REDIS" updateMode="DEFAULT" broadcastSessionEvents="false"
     keyPrefix=""/>

keyPrefix - string prefix applied to all keys. Allows to connect different Tomcat environments to the same Redis or Valkey instance.

readMode - read Session 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 or Valkey only. Default mode.

broadcastSessionEvents - if true then sessionCreated and sessionDestroyed events are broadcasted across all Tomcat instances and cause all registered HttpSessionListeners to be triggered. Default is false.

broadcastSessionUpdates - if true and readMode=MEMORY then session updates are broadcasted across all Tomcat instances. Default is true.

updateMode - Session attributes update mode. Two modes are available:

• DEFAULT - session attributes are stored into Redis or Valkey only through the Session.setAttribute method. Default mode.
• AFTER_REQUEST
  • In readMode=REDIS all changes of session attributes made through the Session.setAttribute method are accumulated in memory and stored into Redis or Valkey only after the end of the request.
  • In readMode=MEMORY all session attributes are always stored into Redis or Valkey after the end of the request regardless of the Session.setAttribute method invocation. It is useful in case when some objects stored in session change their own state without Session.setAttribute method execution. Updated attributes are removed from all other Session instances if broadcastSessionUpdates=true and reloaded from Redis or Valkey when these attributes are requested.

configPath - path to Redisson YAML config. See configuration page for more details. In case session manager is configured programatically, a config object can be passed using the setConfig() method

Shared Redisson instance

Amount of Redisson instances created by Tomcat for multiple contexts could be reduced through JNDI registry:

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

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

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

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

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

2. Copy two jars into TOMCAT_BASE/lib directory:

redisson-all-3.36.0.jar

Tomcat 7.x - redisson-tomcat-7-3.36.0.jar

Tomcat 8.x - redisson-tomcat-8-3.36.0.jar

Tomcat 9.x - redisson-tomcat-9-3.36.0.jar

Tomcat 10.x - redisson-tomcat-10-3.36.0.jar

Upgrade to Redisson PRO with advanced features.

Spring Session

For Spring Session usage please refer to Spring Session article.

Micronaut Session

For Micronaut Session usage please refer to Micronaut Session article.