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hecnabae
Asked: 2020-01-17 03:09:49 +0800 CST 2020-01-17 03:09:49 +0800 CST

Persistent session configuration issue in Tomcat

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I am trying to configure Tomcat 8.5.9 to boot in persistent session mode and store the session in MySql. For this I have followed the procedure described in the Tomcat documentation :

  1. Create the tomcat_sessions table, as indicated in the documentation:
create table tomcat_sessions (
  session_id     varchar(100) not null primary key,
  valid_session  char(1) not null,
  max_inactive   int not null,
  last_access    bigint not null,
  app_name       varchar(255),
  session_data   mediumblob,
  KEY kapp_name(app_name)
);
  1. Second, I have inserted the mysql-connector-java-5.1.40-bin.jar library into the tomcat classpath.

  2. Finally I have modified the context.xml file as follows:

    <?xml version="1.0" encoding="UTF-8"?>
<Context>
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
    <WatchedResource>${catalina.base}/conf/web.xml</WatchedResource>

    <Manager className="org.apache.catalina.session.PersistentManager"     
    debug="0"
    maxActiveSessions="-1"
    maxIdleBackup="-1"
    minIdleSwap="-1"
    maxIdleSwap="-1"
    processExpiresFrequency="1"
    saveOnRestart='true'
    >

        <Store className="org.apache.catalina.session.JDBCStore"        
            connectionName="root"
            connectionPassword="password"
            connectionURL="jdbc:mysql://localhost:3306/tomcat"
            driverName="com.mysql.jdbc.Driver"
            />
</Manager>
</Context>

When I run Tomcat, I get the following error:

16-Jan-2017 11:55:04.597 GRAVE [localhost-startStop-1] org.apache.catalina.core.StandardContext.startInternal The session manager failed to start
 org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.session.PersistentManager[/manager]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5206)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1107)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1841)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.session.JDBCStore[org.apache.catalina.session.PersistentManager[/manager]]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
    at org.apache.catalina.session.PersistentManagerBase.startInternal(PersistentManagerBase.java:847)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 12 more
Caused by: java.lang.NullPointerException
    at org.apache.catalina.session.JDBCStore.open(JDBCStore.java:906)
    at org.apache.catalina.session.JDBCStore.getConnection(JDBCStore.java:839)
    at org.apache.catalina.session.JDBCStore.startInternal(JDBCStore.java:1001)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 14 more
tomcat

1 Answers

  1. Best Answer

    According to the source code, line 906 where you have the NullPointer is the one that sets the autocommit:

       // Open a new connection
    Properties props = new Properties();
    if (connectionName != null)
        props.put("user", connectionName);
    if (connectionPassword != null)
        props.put("password", connectionPassword);
    dbConnection = driver.connect(connectionURL, props);
    dbConnection.setAutoCommit(true);
    return dbConnection;

    So the Driver seems to be finding it fine, but it can't create the connection. Make sure the connection url, port, user and passwd are correct.

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