I am working on a project where I need to replicate sessions on two different tomcats. I configured Nginx as a load balancer. Configured two tomcats to make two different nodes.
My requirement: Suppose two nodes are running and the session of node one is replicated in node two. And end-user is getting response from node one. If node one is down then the user will not get session out and continue with node two with the same session.
Whats happening now: Two nodes are running and session is replicated to both nodes. User getting response from node one. Node one down and user gets a session-out message.
I configured the tomcat clustering mechanism like tomcat documentation from this site
I configured tomcat 1's server.xml file like
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
channelSendOptions="6">
<Manager className="org.apache.catalina.ha.session.BackupManager"
expireSessionsOnShutdown="false"
notifyListenersOnReplication="true"
mapSendOptions="6"/>
<!--
<Manager className="org.apache.catalina.ha.session.DeltaManager"
expireSessionsOnShutdown="false"
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="5000"
selectorTimeout="100"
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.MessageDispatchInterceptor"/>
<Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/>
</Channel>
<Valve className="org.apache.catalina.ha.tcp.ReplicationValve"
filter=".*\.gif|.*\.js|.*\.jpeg|.*\.jpg|.*\.png|.*\.htm|.*\.html|.*\.css|.*\.txt"/>
<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.ClusterSessionListener"/>
</Cluster>
And tomcat 2's server.xml file like
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
channelSendOptions="6">
<Manager className="org.apache.catalina.ha.session.BackupManager"
expireSessionsOnShutdown="false"
notifyListenersOnReplication="true"
mapSendOptions="6"/>
<!--
<Manager className="org.apache.catalina.ha.session.DeltaManager"
expireSessionsOnShutdown="false"
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="5001"
selectorTimeout="100"
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.MessageDispatchInterceptor"/>
<Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/>
</Channel>
<Valve className="org.apache.catalina.ha.tcp.ReplicationValve"
filter=".*\.gif|.*\.js|.*\.jpeg|.*\.jpg|.*\.png|.*\.htm|.*\.html|.*\.css|.*\.txt"/>
<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.ClusterSessionListener"/>
</Cluster>
My web.xml file of my spring project is
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
<display-name>Enterprise Web App</display-name>
<filter>
<filter-name>springSecurityFilterChain</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
<filter-name >springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>
org.springframework.web.context.request.RequestContextListener
</listener-class>
</listener>
<!--start real ip filter for ngnix-->
<filter>
<filter-name>RealIPFilter</filter-name>
<filter-class>com.brainstation.corporate.ib.webapp.provider.ip.RealIPFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>RealIPFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!--end real ip filter for ngnix-->
<servlet>
<servlet-name>web-app</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>web-app</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<context-param>
<param-name>spring.profiles.active</param-name>
<param-value>dev</param-value>
</context-param>
<session-config>
<session-timeout>0</session-timeout>
<cookie-config>
<name>EB_JSESSIONID</name>
<http-only>true</http-only>
</cookie-config>
<tracking-mode>COOKIE</tracking-mode>
</session-config>
<distributable/>
</web-app>
And my nginx configuration on /etc/nginx/sites-available/default file
upstream backend {
ip_hash;
server localhost:7070 max_fails=3 fail_timeout=10s;
server localhost:7080 max_fails=3 fail_timeout=10s;
#server localhost:7090 max_fails=3 fail_timeout=10s;
}
server {
listen 80 default_server;
listen [::]:80 default_server;
#server_name hellobs23.com
# SSL configuration
#
# listen 443 ssl default_server;
# listen [::]:443 ssl default_server;
#
# Note: You should disable gzip for SSL traffic.
# See: https://bugs.debian.org/773332
#
# Read up on ssl_ciphers to ensure a secure configuration.
# See: https://bugs.debian.org/765782
#
# Self signed certs generated by the ssl-cert package
# Don't use them in a production server!
#
# include snippets/snakeoil.conf;
root /var/www/html;
# Add index.php to the list if you are using PHP
index index.html index.htm index.nginx-debian.html;
location / {
proxy_pass http://backend;
error_page 500 502 503 504 /50x.html;
}
# pass PHP scripts to FastCGI server
#
#location ~ \.php$ {
# include snippets/fastcgi-php.conf;
#
# # With php-fpm (or other unix sockets):
# fastcgi_pass unix:/run/php/php7.4-fpm.sock;
# # With php-cgi (or other tcp sockets):
# fastcgi_pass 127.0.0.1:9000;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
And one interesting thing is the same configuration working on another project but not working on my project. I have been desperately looking for a solution for 4 days. Could not find anything that could give me relief.
You can also use memcache session manager to solve your issue. Please refer the link for description memcache session manager
And set up information can be found on this link Setup and configuration