Java Bundle

Create tomcat clustering

2009-04-04T14:43:00.004+05:30

Tomcat clustering can be used for serving request routed through Apache HTTP Server.

Tomcat cluser setup can be created on single or different machine and accessed from Apache Http Server using JK connector.

Following text need to be copied in server.xml file in config folder of Tomcat.

<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
channelSendOptions="8">

<Manager className="org.apache.catalina.ha.session.DeltaManager"
expireSessionsOnShutdown="true"
notifyListenersOnReplication="true"/>

<Channel className="org.apache.catalina.tribes.group.GroupChannel">
<Membership className="org.apache.catalina.tribes.membership.McastService"
address="228.0.0.4"
port="45564"
frequency="500"
dropTime="3000"/>
<Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
address="auto"
port="4000"
autoBind="100"
selectorTimeout="5000"
maxThreads="6"/>

<Sender className="org.apache.catalina.tribes.transport.ReplicationTransmitter">
<Transport className="org.apache.catalina.tribes.transport.nio.PooledParallelSender"/>
</Sender>
<Interceptor className="org.apache.catalina.tribes.group.interceptors.TcpFailureDetector"/>
<Interceptor className="org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor"/>
</Channel>

<Valve className="org.apache.catalina.ha.tcp.ReplicationValve"
filter=""/>
<Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/>

<Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer"
tempDir="/tmp/war-temp/"
deployDir="/tmp/war-deploy/"
watchDir="/tmp/war-listen/"
watchEnabled="false"/>

<ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/>
<ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/>
</Cluster>

Connecting MySQL from OpenEJB

2009-04-04T12:52:00.004+05:30

You can use OpenEJB war to get the functionality of EJB into Tomcat.
Place the following text in openejb.xml file in config folder of Tomcat. For this setting to work your user table should have minimum one row present for root user.

JdbcDriver com.mysql.jdbc.Driver
JdbcUrl jdbc:mysql://192.168.0.101:3306/DataBaseName
UserName root
Password password
InitialSize 10
ConnectionProperties connectTimeout=10000;socketTimeout=10000;
MaxActive 1800
MaxIdle 500
MinIdle 10
MaxWait 10000
ValidationQuery select * from User where UserId='root';
TestWhileIdle true
TimeBetweenEvictionRunsMillis 10000
JtaManaged true

Using JK connector

2009-03-25T13:48:00.007+05:30

JK connector is used to serve request from tomcat webservers. JK module is loaded into Apache Http Server optionally using following lines in httpd.conf file under conf folder of Apache installation directory.
LoadModule jk_module modules/mod_jk.so

Single or Multiple tomcat server (Clustered configurations) can be used to serve request. Tomcat server need to defined in worker.properties files which will be loaded into apache conf file.
workers.tomcat_home=/tomcatA
workers.java_home="/usr/java/jdk1.6.0_06"
ps=/
worker.list=loadbalancer

worker.tomcatA.port=8109
worker.tomcatA.host=192.168.0.11
worker.tomcatA.type=ajp13
worker.tomcatA.lbfactor=1
worker.tomcatA.socket_timeout=1
worker.tomcatA.connect_timeout=1000
worker.tomcatA.prepost_timeout=1000
worker.tomcatA.reply_timeout=600000
worker.tomcatA.socket_keepalive=False
worker.tomcatA.connection_pool_size=5000
worker.tomcatA.connection_pool_minsize=500
worker.tomcatA.connection_pool_timeout=300
worker.tomcatA.redirect=tomcatB

worker.tomcatB.port=8209
worker.tomcatB.host=192.168.0.12
worker.tomcatB.type=ajp13
worker.tomcatB.lbfactor=1
worker.tomcatB.socket_timeout=1
worker.tomcatB.connect_timeout=1000
worker.tomcatB.prepost_timeout=1000
worker.tomcatB.reply_timeout=600000
worker.tomcatB.socket_keepalive=False
worker.tomcatB.connection_pool_size=5000
worker.tomcatB.connection_pool_minsize=500
worker.tomcatB.connection_pool_timeout=300
worker.tomcatB.redirect=tomcatA

worker.loadbalancer.type=lb
worker.loadbalancer.balance_workers=tomcatA,tomcatB
worker.loadbalancer.sticky_session=True
worker.loadbalancer.retries=2

Configurations for loading worker file into apache conf file.
JkWorkersFile "/etc/httpd/conf/workers.properties"
JkShmFile "/var/log/httpd/mod_jk.shm"
JkLogFile "/etc/httpd/logs/mod_jk.log"
JkLogLevel info

You can mount a particular folder or project or mount all to pass every thing to tomcat. Few sample configuration are listed below.
JkMount /* loadbalancer
JkMount /servlet/* loadbalancer
JkMount /jsp/* loadbalancer
JkMount /project tomcatA
JkMount /project/jsp/* loadbalancer
Filter request from forwarding to tomcat for html, jpg and gif and can be served from apache http server.
JkUnMount /project/*.html loadbalancer
JkUnMount /project/*.jpg loadbalancer

For single tomcat server you don't require loadbalancer configuration. Only tomcatA will server the request and can be used in place of loadbalancer.