Build a Web cluster with Haproxy and implement dual-machine hot standby by keepalived

Build haproxy+keepalived high-availability clusters.

I. Overview of the case

1.haproxy is currently a popular cluster scheduling tool, is a free Cost-open source software, and has a certain security; Haproxy is more suitable for web nodes that are heavily loaded and supports tens of thousands of concurrency . There are many similar scheduling tools, such as LVS and Nginx. In comparison, LVS performance is the best, but the construction of relatively complex, Nginx upstream module support cluster function, but the cluster node health Check function is not strong, performance is not haproxy good. Haproxy primarily implements load balancing for Web clusters Haproxy official website: http://haproxy.1wt.eu/.

2. Load Balancing scheduling algorithm:

①.RR (Round Robin): Polling, assigning access requests in turn based on node weights.

②.LC (Least Connect): The minimum number of connections algorithm that allocates access requests based on the number of connections to a node, assigning connection requests to clients with the least number of connections each time. is one of the more algorithms used at present.

③.sh (source Hashing): A source-based access scheduling algorithm. Can be based on IP, cookies, such as cluster scheduling, such as IP1 first access was assigned to a site, IP2 access is assigned to the B site, then each ip1 will be assigned to a site, IP2 is assigned to the B site. If a certain amount of IP access is large, it will cause a lot of pressure on the node.

3. Case Environment:

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Second, compile and install Haproxy (here take the main Haproxy server example)

1. Install the Haproxy-enabled development kit with Yum first

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2: Compile and install Haproxy.

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3. Configuring the Haproxy Server

To manually establish the Haproxy profile directory, copy the Haproxy.cfg file to the configuration file directory you just created manually.

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4. Modify the Haproxy configuration file

Haproxy is usually divided into three parts (global: Globally configured, defaults: Default configuration, Listen: Application module Configuration)

First modify the global configuration: 650) this.width=650; "Src=" Http://s3.51cto.com/wyfs02/M02/8A/04/wKiom1gj84bQviEjAACpa6F-sO4169.jpg-wh_ 500x0-wm_3-wmp_4-s_142082311.jpg "title=" qq picture 20161110121130.jpg "alt=" wkiom1gj84bqviejaacpa6f-so4169.jpg-wh_50 "/ >

Next is the default configuration:

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Finally, for the application module configuration:

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Save to exit.

5. Create a self-launching script

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Three. Testing the Web cluster

1. Build test page 650) this.width=650; "Src=" Http://s5.51cto.com/wyfs02/M00/8A/05/wKiom1gj923RXrGIAAAKr5s_kuA981.png-wh_ 500x0-wm_3-wmp_4-s_771027046.png "title=" qq picture 20161110122801.png "alt=" wkiom1gj923rxrgiaaakr5s_kua981.png-wh_50 "/ >

Launch Apache Service

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2. Test the page that was displayed for the first time Web1

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WEB2 page for the second time display

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Iv. High Availability of Haproxy

1. Installing support software

yum-y Install kernel-devel openssl-devel popt-devel ipvsadm

2. Compile and install keepalived and add keepalived as a system service

cd/usr/src/keepalived-1.2.13/

./configure--prefix=/--with-kernel-dir=/usr/src/kernels/2.6.32-431.el6.x86_64/&& make && make Install

Ls-l/etc/init.d/keepalived

Chkconfig--add keepalived

3. Using keepalived to realize dual-machine hot standby

First configure the primary scheduler, the primary haproxy (/etc/keepalived/keepalived.conf)

To modify the keepalived configuration file:

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2. Configure the Slave Scheduler

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3. Restart keepalived after configuration

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4. Use the client to browse the Web through the cluster. The effect is as follows:

(Change the cluster IP to 192.168.1.20 due to address conflicts)

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The client will still be able to access the main haproxy when the network card is disconnected.

Note: The author's knowledge is limited, I hope you will put forward valuable comments!

This article is from the "Breeze with You" blog, please be sure to keep this source http://super12138.blog.51cto.com/12190541/1871474

Build a Web cluster with Haproxy and implement dual-machine hot standby by keepalived