Tutorial de Tomcat en Cluster

Lo primero que necesitaremos será descargar el servidor Web Apache para poder hacer el balanceo de carga (Load Balancing) y la compartición de carga (Load Sharing).

Para esto, descargaremos el archivo apache_2.2.9-win32-x86-no_ssl-r2.msi desde aquí. Una vez descargado, procedemos a la instalación.

Ya instalado el servidor Web Apache, deberemos proceder a instalar Tomcat y definir el tipo de cluster a implementar.

Existen dos tipos de cluster que podemos construir en Tomcat: cluster vertical (en una sola maquina) o cluster horizontal (en muchas maquinas).


Cluster vertical

El primer paso será la instalación de Tomcat, para lo que deberemos bajar el archivo apache-tomcat-6.0.9.exe desde aquí.

Una vez descargado el archivo, procederemos instalar Tomcat. Para este ejemplo, vamos a simular que el cluster está compuesto por tres nodos, por lo tanto, necesitaremos instalar tres instancias de Tomcat las cuales llamaremos: TomcatNodo1, TomcatNodo2 y TomcatNodo3.

El paso que realizaremos a continuación deberemos repetirlo para cada nodo.







Una vez instalado los tres nodos, deberemos realizar una pequeña modificación al archivo server.xml de cada uno de los nodos. Este archivo se encuentra en la carpeta "conf" de cada uno de los nodos.

Para cada uno de los server.xml deberemos realizar los siguientes cambios:

Cambiar los puertos

<br /><server port="XXXX" shutdown="SHUTDOWN"><br /><br /> <connector port="XXXX" protocol="HTTP/1.1" connectiontimeout="20000" redirectport="8443"><br /><br /> <connector port="XXXX" protocol="AJP/1.3" redirectport="8443">

Agregamos el “jvmRoute” para cada caso.

<br /><engine name="Catalina" defaulthost="localhost" jvmroute="tomcatNodoX"><br /><br />

Descomentamos el tag “cluster”

<br /><cluster classname="org.apache.catalina.ha.tcp.SimpleTcpCluster"><br /><br />

Nodo1

<br /><!-- Note: A "Server" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/server.html --><br /><br /><server port="8015" shutdown="SHUTDOWN"><br /><br /><br /><br /> <!--APR library loader. Documentation at /docs/apr.html --><br /><br /> <listener classname="org.apache.catalina.core.AprLifecycleListener" sslengine="on"><br /><br /> <!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html --><br /><br /> <listener classname="org.apache.catalina.core.JasperListener"><br /><br /> <!-- JMX Support for the Tomcat server. Documentation at /docs/non-existent.html --><br /><br /> <listener classname="org.apache.catalina.mbeans.ServerLifecycleListener"><br /><br /> <listener classname="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"><br /><br /><br /><br /> <!-- Global JNDI resources Documentation at /docs/jndi-resources-howto.html --><br /><br /> <globalnamingresources><br /><br /> <!-- Editable user database that can also be used by UserDatabaseRealm to authenticate users --><br /><br /> <resource name="UserDatabase" auth="Container" type="org.apache.catalina.UserDatabase" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" pathname="conf/tomcat-users.xml"><br /><br /> </globalnamingresources><br /><br /><br /><br /> <!-- A "Service" is a collection of one or more "Connectors" that share a single "Container" Note: A "Service" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/service.html --><br /><br /> <service name="Catalina"><br /><br /><br /><br /> <!-- A "Connector" represents an endpoint by which requests are received and responses are returned. Documentation at : Java HTTP Connector: /docs/config/http.html (blocking & non-blocking) Java AJP Connector: /docs/config/ajp.html APR (HTTP/AJP) Connector: /docs/apr.html Define a non-SSL HTTP/1.1 Connector on port 8080 --><br /><br /> <connector port="8081" protocol="HTTP/1.1" maxthreads="150" connectiontimeout="20000" redirectport="8443"><br /><br /><br /><br /> <!-- Define a SSL HTTP/1.1 Connector on port 8443 This connector uses the JSSE configuration, when using APR, the connector should be using the OpenSSL style configuration described in the APR documentation --><br /><br /> <!-- <connector port="8443" protocol="HTTP/1.1" sslenabled="true" maxthreads="150" scheme="https" secure="true" clientauth="false" sslprotocol="TLS"><br /><br /> --><br /><br /><br /><br /> <!-- Define an AJP 1.3 Connector on port 8009 --><br /><br /> <connector port="8109" protocol="AJP/1.3" redirectport="8443"><br /><br /><br /><br /><br /><br /> <!-- An Engine represents the entry point (within Catalina) that processes every request. The Engine implementation for Tomcat stand alone analyzes the HTTP headers included with the request, and passes them on to the appropriate Host (virtual host). Documentation at /docs/config/engine.html --><br /><br /><br /><br /> <!-- You should set jvmRoute to support load-balancing via AJP ie : --><br /><br /> <engine name="Standalone" defaulthost="localhost" jvmroute="tomcatNodo1"> <br /><br /> <br /><br /> <engine name="Catalina" defaulthost="localhost"><br /><br /><br /><br /> <!--For clustering, please take a look at documentation at: /docs/cluster-howto.html (simple how to) /docs/config/cluster.html (reference documentation) --><br /><br /> <br /><br /> <cluster classname="org.apache.catalina.ha.tcp.SimpleTcpCluster"><br /><br /> <br /><br /><br /><br /> <!-- The request dumper valve dumps useful debugging information about the request and response data received and sent by Tomcat. Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.valves.RequestDumperValve"><br /><br /> --><br /><br /><br /><br /> <!-- This Realm uses the UserDatabase configured in the global JNDI resources under the key "UserDatabase". Any edits that are performed against this UserDatabase are immediately available for use by the Realm. --><br /><br /> <realm classname="org.apache.catalina.realm.UserDatabaseRealm" resourcename="UserDatabase"><br /><br /><br /><br /> <!-- Define the default virtual host Note: XML Schema validation will not work with Xerces 2.2. --><br /><br /> <host name="localhost" appbase="webapps" unpackwars="true" autodeploy="true" xmlvalidation="false" xmlnamespaceaware="false"><br /><br /><br /><br /> <!-- SingleSignOn valve, share authentication between web applications Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.authenticator.SingleSignOn"><br /><br /> --><br /><br /><br /><br /> <!-- Access log processes all example. Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log." suffix=".txt" pattern="common" resolvehosts="false"><br /><br /> --><br /><br /><br /><br /> </host><br /><br /> </engine><br /><br /> </service><br /><br /></server><br /><br />

Nodo2

<br /><!-- Note: A "Server" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/server.html --><br /><br /><server port="8205" shutdown="SHUTDOWN"><br /><br /><br /><br /> <!--APR library loader. Documentation at /docs/apr.html --><br /><br /> <listener classname="org.apache.catalina.core.AprLifecycleListener" sslengine="on"><br /><br /> <!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html --><br /><br /> <listener classname="org.apache.catalina.core.JasperListener"><br /><br /> <!-- JMX Support for the Tomcat server. Documentation at /docs/non-existent.html --><br /><br /> <listener classname="org.apache.catalina.mbeans.ServerLifecycleListener"><br /><br /> <listener classname="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"><br /><br /><br /><br /> <!-- Global JNDI resources Documentation at /docs/jndi-resources-howto.html --><br /><br /> <globalnamingresources><br /><br /> <!-- Editable user database that can also be used by UserDatabaseRealm to authenticate users --><br /><br /> <resource name="UserDatabase" auth="Container" type="org.apache.catalina.UserDatabase" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" pathname="conf/tomcat-users.xml"><br /><br /> </globalnamingresources><br /><br /><br /><br /> <!-- A "Service" is a collection of one or more "Connectors" that share a single "Container" Note: A "Service" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/service.html --><br /><br /> <service name="Catalina"><br /><br /><br /><br /> <!-- A "Connector" represents an endpoint by which requests are received and responses are returned. Documentation at : Java HTTP Connector: /docs/config/http.html (blocking & non-blocking) Java AJP Connector: /docs/config/ajp.html APR (HTTP/AJP) Connector: /docs/apr.html Define a non-SSL HTTP/1.1 Connector on port 8080 --><br /><br /> <connector port="8082" protocol="HTTP/1.1" maxthreads="150" connectiontimeout="20000" redirectport="8443"><br /><br /><br /><br /> <!-- Define a SSL HTTP/1.1 Connector on port 8443 This connector uses the JSSE configuration, when using APR, the connector should be using the OpenSSL style configuration described in the APR documentation --><br /><br /> <!-- <connector port="8443" protocol="HTTP/1.1" sslenabled="true" maxthreads="150" scheme="https" secure="true" clientauth="false" sslprotocol="TLS"><br /><br /> --><br /><br /><br /><br /> <!-- Define an AJP 1.3 Connector on port 8009 --><br /><br /> <connector port="8209" protocol="AJP/1.3" redirectport="8443"><br /><br /><br /><br /><br /><br /> <!-- An Engine represents the entry point (within Catalina) that processes every request. The Engine implementation for Tomcat stand alone analyzes the HTTP headers included with the request, and passes them on to the appropriate Host (virtual host). Documentation at /docs/config/engine.html --><br /><br /><br /><br /> <!-- You should set jvmRoute to support load-balancing via AJP ie : --> <br /><br /> <engine name="Standalone" defaulthost="localhost" jvmroute="tomcatNodo2"> <br /><br /> <br /><br /> <engine name="Catalina" defaulthost="localhost"><br /><br /><br /><br /> <!--For clustering, please take a look at documentation at: /docs/cluster-howto.html (simple how to) /docs/config/cluster.html (reference documentation) --><br /><br /> <br /><br /> <cluster classname="org.apache.catalina.ha.tcp.SimpleTcpCluster"><br /><br /> <br /><br /><br /><br /> <!-- The request dumper valve dumps useful debugging information about the request and response data received and sent by Tomcat. Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.valves.RequestDumperValve"><br /><br /> --><br /><br /><br /><br /> <!-- This Realm uses the UserDatabase configured in the global JNDI resources under the key "UserDatabase". Any edits that are performed against this UserDatabase are immediately available for use by the Realm. --><br /><br /> <realm classname="org.apache.catalina.realm.UserDatabaseRealm" resourcename="UserDatabase"><br /><br /><br /><br /> <!-- Define the default virtual host Note: XML Schema validation will not work with Xerces 2.2. --><br /><br /> <host name="localhost" appbase="webapps" unpackwars="true" autodeploy="true" xmlvalidation="false" xmlnamespaceaware="false"><br /><br /><br /><br /> <!-- SingleSignOn valve, share authentication between web applications Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.authenticator.SingleSignOn"><br /><br /> --><br /><br /><br /><br /> <!-- Access log processes all example. Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log." suffix=".txt" pattern="common" resolvehosts="false"><br /><br /> --><br /><br /><br /><br /> </host><br /><br /> </engine><br /><br /> </service><br /><br /></server><br /><br />

Nodo3

<br /><!-- Note: A "Server" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/server.html --><br /><br /><server port="8305" shutdown="SHUTDOWN"><br /><br /><br /><br /> <!--APR library loader. Documentation at /docs/apr.html --><br /><br /> <listener classname="org.apache.catalina.core.AprLifecycleListener" sslengine="on"><br /><br /> <!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html --><br /><br /> <listener classname="org.apache.catalina.core.JasperListener"><br /><br /> <!-- JMX Support for the Tomcat server. Documentation at /docs/non-existent.html --><br /><br /> <listener classname="org.apache.catalina.mbeans.ServerLifecycleListener"><br /><br /> <listener classname="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"><br /><br /><br /><br /> <!-- Global JNDI resources Documentation at /docs/jndi-resources-howto.html --><br /><br /> <globalnamingresources><br /><br /> <!-- Editable user database that can also be used by UserDatabaseRealm to authenticate users --><br /><br /> <resource name="UserDatabase" auth="Container" type="org.apache.catalina.UserDatabase" description="User database that can be updated and saved" factory="org.apache.catalina.users.MemoryUserDatabaseFactory" pathname="conf/tomcat-users.xml"><br /><br /> </globalnamingresources><br /><br /><br /><br /> <!-- A "Service" is a collection of one or more "Connectors" that share a single "Container" Note: A "Service" is not itself a "Container", so you may not define subcomponents such as "Valves" at this level. Documentation at /docs/config/service.html --><br /><br /> <service name="Catalina"><br /><br /><br /><br /> <!-- A "Connector" represents an endpoint by which requests are received and responses are returned. Documentation at : Java HTTP Connector: /docs/config/http.html (blocking & non-blocking) Java AJP Connector: /docs/config/ajp.html APR (HTTP/AJP) Connector: /docs/apr.html Define a non-SSL HTTP/1.1 Connector on port 8080 --><br /><br /> <connector port="8083" protocol="HTTP/1.1" maxthreads="150" connectiontimeout="20000" redirectport="8443"><br /><br /><br /><br /> <!-- Define a SSL HTTP/1.1 Connector on port 8443 This connector uses the JSSE configuration, when using APR, the connector should be using the OpenSSL style configuration described in the APR documentation --><br /><br /> <!-- <connector port="8443" protocol="HTTP/1.1" sslenabled="true" maxthreads="150" scheme="https" secure="true" clientauth="false" sslprotocol="TLS"><br /><br /> --><br /><br /><br /><br /> <!-- Define an AJP 1.3 Connector on port 8009 --><br /><br /> <connector port="8309" protocol="AJP/1.3" redirectport="8443"><br /><br /><br /><br /><br /><br /> <!-- An Engine represents the entry point (within Catalina) that processes every request. The Engine implementation for Tomcat stand alone analyzes the HTTP headers included with the request, and passes them on to the appropriate Host (virtual host). Documentation at /docs/config/engine.html --><br /><br /><br /><br /> <!-- You should set jvmRoute to support load-balancing via AJP ie : --> <br /><br /> <engine name="Standalone" defaulthost="localhost" jvmroute="tomcatNodo3"> <br /><br /> <br /><br /> <engine name="Catalina" defaulthost="localhost"><br /><br /><br /><br /> <!--For clustering, please take a look at documentation at: /docs/cluster-howto.html (simple how to) /docs/config/cluster.html (reference documentation) --><br /><br /> <br /><br /> <cluster classname="org.apache.catalina.ha.tcp.SimpleTcpCluster"><br /><br /> <br /><br /><br /><br /> <!-- The request dumper valve dumps useful debugging information about the request and response data received and sent by Tomcat. Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.valves.RequestDumperValve"><br /><br /> --><br /><br /><br /><br /> <!-- This Realm uses the UserDatabase configured in the global JNDI resources under the key "UserDatabase". Any edits that are performed against this UserDatabase are immediately available for use by the Realm. --><br /><br /> <realm classname="org.apache.catalina.realm.UserDatabaseRealm" resourcename="UserDatabase"><br /><br /><br /><br /> <!-- Define the default virtual host Note: XML Schema validation will not work with Xerces 2.2. --><br /><br /> <host name="localhost" appbase="webapps" unpackwars="true" autodeploy="true" xmlvalidation="false" xmlnamespaceaware="false"><br /><br /><br /><br /> <!-- SingleSignOn valve, share authentication between web applications Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.authenticator.SingleSignOn"><br /><br /> --><br /><br /><br /><br /> <!-- Access log processes all example. Documentation at: /docs/config/valve.html --><br /><br /> <!-- <valve classname="org.apache.catalina.valves.AccessLogValve" directory="logs" prefix="localhost_access_log." suffix=".txt" pattern="common" resolvehosts="false"><br /><br /> --><br /><br /><br /><br /> </host><br /><br /> </engine><br /><br /> </service><br /><br /></server><br /><br />


Con estos cambios ya tenemos configurado nuestro cluster vertical.


Cluster Horizontal

La configuración de un cluster horizontal es un poco más fácil ya que no es necesario realizar cambios a los puertos.

Para cada uno de los archivos server.xml se debe realizar los siguientes cambios:

Agregamos el “jvmRoute” para cada caso (igual que para el cluster vertical)

<br /><engine name="Catalina" defaulthost="localhost" jvmroute="tomcatNodoX"><br /><br />

Descomentamos el tag “cluster” (igual que para el cluster vertical)

<br /><cluster classname="org.apache.catalina.ha.tcp.SimpleTcpCluster"><br /><br />


Configuración del cluster con Apache

Una vez configurado el tipo de cluster (Horizontal o Vertical), vamos a construir una pequeña aplicación de ejemplo.

El primer paso será definir en el web.xml de la aplicación el tag <distributable /> para activar el intercambio de la sesión a través de la instancia del cluster.

<br /><?xml version="1.0" encoding="ISO-8859-1"?><br /><br /><web-app xmlns="http://java.sun.com/xml/ns/javaee" xsi="http://www.w3.org/2001/XMLSchema-instance" schemalocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"><br /><br /> <distributable> <br /><br /></web-app><br /><br />

Ahora necesitaremos integrar el servidor web Apache con Tomcat instalando el modulo mod_jk. Para esto, deberemos descargar el archivo mod_jk-1.2.26-httpd-2.2.4.so desde aquí y dejarlo en la carpeta “modules” de Apache.

Ya instalado el mod_jk, deberemos editar el archivo httpd.conf que está en la carpeta “conf” con las siguientes líneas:

<br />LoadModule jk_module modules/mod_jk-1.2.26-httpd-2.2.4.so<br /><br />JkWorkersFile "C:\Archivos de programa\Apache Software Foundation\Apache2.2\conf\workers.properties"<br /><br />JkLogFile "logs/mod_jk.log"<br /><br />JkLogLevel error<br /><br />JkMount /cluster loadbalancer<br /><br />JkMount /cluster/* loadbalancer<br /><br />

Ahora deberemos crear el archivo workers.properties dentro de la carpeta “conf” del Apache. En este archivo definiremos las propiedades para cada una de las instancias de Tomcat a ejecutar.

En el caso de que nuestro cluster sea vertical, el archivo de propiedades deberá contener lo siguiente:

<br />workers.tomcat_home=/tomcatNodo1<br /><br />workers.java_home=$JAVA_HOME<br /><br />ps=/<br /><br />worker.list=tomcatNodo1,tomcatNodo2,tomcatNodo3,loadbalancer<br /><br /><br /><br />worker.tomcatNodo1.port=8109<br /><br />worker.tomcatNodo1.host=localhost<br /><br />worker.tomcatNodo1.type=ajp13<br /><br />worker.tomcatNodo1.lbfactor=1<br /><br /><br /><br />worker.tomcatNodo2.port=8209<br /><br />worker.tomcatNodo2.host=localhost<br /><br />worker.tomcatNodo2.type=ajp13<br /><br />worker.tomcatNodo2.lbfactor=1<br /><br /><br /><br />worker.tomcatNodo3.port=8309<br /><br />worker.tomcatNodo3.host=localhost<br /><br />worker.tomcatNodo3.type=ajp13<br /><br />worker.tomcatNodo3.lbfactor=1<br /><br /><br /><br />worker.loadbalancer.type=lb<br /><br />worker.loadbalancer.balanced_workers=tomcatNodo1,tomcatNodo2,tomcatNodo3<br /><br />worker.loadbalancer.sticky_session=1<br /><br />

Para el caso de que el cluster sea horizontal deberemos definir el host para cada uno de los nodos del cluster:

<br />workers.tomcat_home=/tomcatNodo1<br /><br />workers.java_home=$JAVA_HOME<br /><br />ps=/<br /><br />worker.list=tomcatNodo1,tomcatNodo2,tomcatNodo3,loadbalancer<br /><br /><br /><br />worker.tomcatNodo1.port=8009<br /><br />worker.tomcatNodo1.host=192.168.1.1<br /><br />worker.tomcatNodo1.type=ajp13<br /><br />worker.tomcatNodo1.lbfactor=1<br /><br /><br /><br />worker.tomcatNodo2.port=8009<br /><br />worker.tomcatNodo2.host=192.168.1.2<br /><br />worker.tomcatNodo2.type=ajp13<br /><br />worker.tomcatNodo2.lbfactor=1<br /><br /><br /><br />worker.tomcatNodo3.port=8009<br /><br />worker.tomcatNodo3.host=192.168.1.3<br /><br />worker.tomcatNodo3.type=ajp13<br /><br />worker.tomcatNodo3.lbfactor=1<br /><br /><br /><br />worker.loadbalancer.type=lb<br /><br />worker.loadbalancer.balanced_workers=tomcatNodo1,tomcatNodo2,tomcatNodo3<br /><br />worker.loadbalancer.sticky_session=1<br /><br />

Uno de los atributos más importantes es “Ibfactor”, el cual define el factor para el balanceo de carga, restringiendo el numero de “request” a enviar a una instancia particular de Tomcat.

Por último, crearemos unas páginas JSP para cada uno de los nodos, con los cuales validaremos que el cluster este funcionado correctamente.


TomcatNodo1

<br /><% session.setAttribute("dukechile","dukechile"); %><br /><br /><html><br /><br /><head><br /><br /><title>DukeChile - Culster</title><br /><br /></head><br /><br /><br /><br /><body><br /><br /><table width="100%" border="0" cellspacing="0" cellpadding="0"><br /><br /> <tr bgcolor="#CCCCCC"><br /><br /> <td width="13%">Tomcat Nodo 1</td><br /><br /> <td width="87%"> </td><br /><br /> </tr><br /><br /> <tr><br /><br /> <td>Session ID :</td><br /><br /> <td><%=session.getId()%></td><br /><br /> </tr><br /><br /></table><br /><br /></body><br /><br /></html><br /><br />

TomcatNodo2

<br /><% session.setAttribute("dukechile","dukechile"); %><br /><br /><html><br /><br /><head><br /><br /><title>DukeChile - Culster</title><br /><br /></head><br /><br /><br /><br /><body><br /><br /><table width="100%" border="0" cellspacing="0" cellpadding="0"><br /><br /> <tr bgcolor="#CCCCCC"><br /><br /> <td width="13%">Tomcat Nodo 2</td><br /><br /> <td width="87%"> </td><br /><br /> </tr><br /><br /> <tr><br /><br /> <td>Session ID :</td><br /><br /> <td><%=session.getId()%></td><br /><br /> </tr><br /><br /></table><br /><br /></body><br /><br /></html><br /><br />

TomcatNodo3

<br /><% session.setAttribute("dukechile","dukechile"); %><br /><br /><html><br /><br /><head><br /><br /><title>DukeChile - Culster</title><br /><br /></head><br /><br /><br /><br /><body><br /><br /><table width="100%" border="0" cellspacing="0" cellpadding="0"><br /><br /> <tr bgcolor="#CCCCCC"><br /><br /> <td width="13%">Tomcat Nodo 3</td><br /><br /> <td width="87%"> </td><br /><br /> </tr><br /><br /> <tr><br /><br /> <td>Session ID :</td><br /><br /> <td><%=session.getId()%></td><br /><br /> </tr><br /><br /></table><br /><br /></body><br /><br /></html><br /><br />


Por último, se debe reiniciar el Apache y luego iniciar cada una de las instancias del Tomcat.

Una vez los nodos estén iniciados, ejecutaremos la página cluster.jsp y validaremos el ID de la sesión asignada además del nombre del nodo que atendió la petición.

Recargamos nuevamente la pagina, y validamos que el ID de la sesión siga siendo la misma, con esto, validamos que el cluster este funcionado correctamente.

Si necesitan ajustar mejor la configuración del cluster, les recomiendo el libro “PROFESIONAL APACHE TOMCAT 6”.