Load Balance Tomcat with Nginx and Store Sessions in Redis
来源:互联网 发布:淘宝店尾页区域怎么改 编辑:程序博客网 时间:2024/05/20 07:15
An awkward title, but that’s exactly what we’re going to do. For some time, I was looking for a way to push code to production systems with zero downtime and zero impact to any active users. Surprisingly, the solution took very little time to implement. At a high level, we have Nginx load balancing two instances of Tomcat. Tomcat stores it’s sessions in Redis. Nginx is configured as non-sticky, since a request can go to any node in the cluster. When we need to push new code, simply take down any Tomcat instance. All current users will now get routed to the active instance. Since session data is externalized in Redis, active users will not be impacted. Once the inactive instance has been updated, bring it up and repeat for the other node.
We’ll start with Nginx:
[raoul@raoul-wp ~]$ sudo rpm -ivh nginx-1.4.2-1.el6.ngx.x86_64.rpm
Edit /etc/nginx/nginx.conf and add the bolded text below
1.
http {
2.
upstream tomcat {
3.
server localhost:8080;
4.
server localhost:8081;
5.
}
6.
include /etc/nginx/mime.types;
7.
default_type application/octet-stream;
Update /etc/nginx/conf.d/default.conf and replace the location section with this:
1.
location / {
2.
proxy_pass http://tomcat;
3.
}
Restart nginx:
[raoul@raoul-wp nginx]$ sudo service nginx restart
Next, install two instances of Tomcat. Change the server ports of the second instance, so that they do not conflict. At this point if you enter https://localhost in your browser, you will be taken to the default tomcat page. However, since we have not setup sticky sessions, every request will get load balanced in round robin, which effectively means it will be creating a new session per request. You can easily see this behavior using the built in tomcat examples. Navigate tohttp://localhost/examples/servlets/servlet/SessionExample and refresh this page a few times and notice the Session ID changing each time. Let us fix this.
Download and install Redis. There is good documentation at http://redis.io/download so I’m not going into the details. Start the server and use the client program to check that it’s working.
Finally, we need to configure Tomcat to store it’s sessions in Redis. For this we’ll be using tomcat-redis-session-manager (https://github.com/jcoleman/tomcat-redis-session-manager). This did not work out-of-the-box and required some tweaking. You will need to download the source code of this project and re-build it after updating the dependent library versions. The versions I used are commons-pool2-2.2.jar and jedis-2.6.1.jar. Copy these jars to the lib directory of both the tomcat instances.
Update the versions of commons-pool, jedis and the tomcat version that you are using in build.gradle of tomcat-redis-session-manager and build the project. Then copy the built tomcat-redis-session-manager-1.2.jar to tomcat lib directory of each instance. Add the following to both the tomcat’s context.xml:
1.
<
Valve
className
=
"com.orangefunction.tomcat.redissessions.RedisSessionHandlerValve"
/>
2.
<
Manager
className
=
"com.orangefunction.tomcat.redissessions.RedisSessionManager"
3.
host
=
"localhost"
4.
port
=
"6379"
5.
database
=
"0"
6.
maxInactiveInterval
=
"60"
/>
Restart the tomcat instances and we’re done. You can now see tomcat’s session in Redis. Use the previous example and try various combinations by taking the tomcat instances up and down. The session data will remain unaffected. I even noticed that if you take down both the instances and then bring them back up, the user’s existing session will be restored.
Thank you for your time.
原文:https://gojagattis.wordpress.com/2014/12/07/load-balance-tomcat-with-nginx-and-store-sessions-in-redis/
- Load Balance Tomcat with Nginx and Store Sessions in Redis
- apache + tomcat load balance and cluster
- Tomcat load balance and clustering - tomcat负载均衡和集群
- nginx load balance
- Nginx TCP Load Balance
- 简易nginx load balance示例
- 使用nginx做load balance
- LVS+Nginx for Load Balance
- Apache/Tomcat with Failover and Load Balancing in 20 minutes or less…
- apache+tomcat+mod_jk load balance
- Dynamic nginx upstreams with Lua and Redis
- Saving PHP Sessions in Redis
- A survey of task allocation and load balance in distributed system阅读笔记
- MEMORY INSTRUCTIONS: LOAD AND STORE
- Vysper cluster, load balance, and LVS
- linux+nginx+tomcat集群(sticky sessions)
- nginx+tomcat+memcached实现sessions共享
- 亲密接触Redis-第三天(Redis的Load Balance)
- 中国天气网天气预报接口
- 利用shareSDK组件进行android第三方登陆
- C#结合GDAL实现规则影像裁剪
- Ext中中文乱码问题解决方法
- Mahout学习之Mahout算法分类
- Load Balance Tomcat with Nginx and Store Sessions in Redis
- 剑指offer--面试题4:替换空格--Java实现
- 【算法】16个无序数最多20次比较找到第二大的数
- 疯狂Java之学习笔记(4)---------------UML及面向对象
- Lazy<T>
- 微软校招2015 Beautiful String
- android intent
- 命令模式command
- x264参数介绍(二、分析和视频可用性信息)