月度归档:2015年05月

Simple keepalived failover setup on Ubuntu 14.04

We are going to set up very simple keepalived IP failover on Ubuntu 14.04. Keepalived is a piece of software which can be used to achieve high availability by assigning two or more nodes a virtual IP and monitoring those nodes, failing over when one goes down. Keepalived can do more, like load balancing and monitoring, but this tutorial focusses on a very simple setup, just IP failover.

Internally keepalived uses VRRP. The VRRP protocol ensures that one of participating nodes is master. The backup node(s) listens for multicast packets from a node with a higher priority. If the backup node fails to receive VRRP advertisements for a period longer than three times of the advertisement timer, the backup node takes the master state and assigns the configured IP(s) to itself. In case there are more than one backup nodes with the same priority, the one with the highest IP wins the election. 继续阅读

Howto setup High-Available HAProxy with Keepalived

Summary

This blog post explains how to setup HAProxy and Keepalived for use with for example the MariaDB Galera cluster setup described here.

The combination of HAProxy and Keepalived will make the MariaDB Galera cluster more resilient and high-available by adding load balancing and transparent failover when a MariaDB cluster node goes down. HAProxy also allows you to separate read and write actions to the MariaDB Galera cluster which is very useful if you want to loadbalance read actions across all MariaDB nodes but want to write to only one MariaDB node.

Since only one of anything is a Single Point of Failure (SPoF) I’ll be using two HAProxy nodes in a high-availability setup. Should the primary HAProxy node fail then Keepalived will initiate an automatic and transparent failover to the secondary HAProxy node. 继续阅读

Nginx: SPDY SSL Installation and Configuration On a Debian / Ubuntu Linux

Google Chrome/Chromium, Firefox and Opera browser support SPDY networking protocol. It enables faster browsing on supported sites. SPDY is similar to HTTP, with particular goals to reduce web page load latency and improve web security. SPDY achieves reduced latency through compression, multiplexing, and prioritization. How do I enable nginx SPDY support running on Debian or Ubuntu Linux server?

SPDY (pronounced as speedy) is an open networking protocol developed primarily at Google for transporting web content. Nginx version 1.4.x+ supports SPDY out of the box. You need openssl version 1.0.1 or above to compile and use nginx. 继续阅读

HowTo: Create a Self-Signed SSL Certificate on Nginx For CentOS / RHEL

I operate a small web site on Cloud server powered by CentOS Linux v6.4. I would like to encrypt my site’s information and create a more secure connection. How do I create a self-signed SSL certificate on Nginx for CentOS/Fedora or Red Hat Enterprise Linux based server?

The ssl encrypts your connection. For example, a visit to https://www.cyberciti.biz/ result into the following:

  1. All pages were encrypted before being transmitted over the Internet.
  2. Encryption makes it very difficult to unauthorized person to view information traveling between client browser and nginx server.

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nginx: Setup SSL Reverse Proxy (Load Balanced SSL Proxy)

A reverse proxy is a proxy server that is installed in a server network. Typically, reverse proxies are used in front of Web servers such as Apache, IIS, and Lighttpd. How do I setup nginx web server as SSL reverse proxy?

When you’ve multiple backend web servers, encryption / SSL acceleration can be done by a reverse proxy. Nginx can act as SSL acceleration software. It provided the following benefits:

  • Easy of use : Nginx is easy to setup and upgrade.
  • Security : Nginx provide an additional layer of defense as Apache is behind the proxy. It can protect against common web-based attacks too.
  • Load Distribution : nginx use very little memory and can distribute the load to several Apache servers. It can even rewrite urls on fly.
  • Caching : Nginx act as a reverse proxy which offload the Web servers by caching static content, such as images, css, js, static html pages and much more.
  • Compression : Nginx can optimize and compress the content to speed up the load time.

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CentOS / Redhat: Install nginx As Reverse Proxy Load Balancer

How do I configure nginx as failover reverse proxy load balancer in front of two Apache web servers under CentOS / RHEL 5.x?

nginx is a Web and Reverse proxy server. Nginx used in front of Apache Web servers. All connections coming from the Internet addressed to one of the Web servers are routed through the nginx proxy server, which may either deal with the request itself or pass the request wholly or partially to the main web servers. 继续阅读

CentOS / Redhat Linux: Install Keepalived To Provide IP Failover For Web Cluster

Keepalived provides a strong and robust health checking for LVS clusters. It implements a framework of health checking on multiple layers for server failover, and VRRPv2 stack to handle director failover. How do I install and configure Keepalived for reverse proxy server such as nginx or lighttpd?

If your are using a LVS director to loadbalance a server pool in a production environment, you may want to have a robust solution for healthcheck & failover. This will also work with reverse proxy server such as nginx. 继续阅读

How to Install and Configure HAProxy on CentOS/RHEL 7/6/5

HAProxy is a very fast and reliable solution for high availability, load balancing, It supports TCP and HTTP-based applications. Now a days most of websites need 99.999% uptime for there site, which are not possible with single server setup. Then we need some high availability environment which can easily manage with single server failure. 继续阅读

IP Failover Setup using KeepAlived on CentOS/RHEL 6

Keepalived is used for IP failover between two servers. It facilities for load balancing and high-availability to Linux based infrastructures. It works on VRRP ( Virtual Router Redundancy Protocol ) protocol. We have running two load balance servers using HAProxy and now we need to implement VRRP between both servers. This tutorial will help you to configure KeepAlived, Use this tutorial to configure HAProxy on both servers. 继续阅读

LVS-HOWTO

LVS-HOWTO

Joseph Mack

jmack (at) wm7d (dot) net

v2012.01 Jan 2012, released under GPL. Note: Mar 2014 This HOWTO is no longer being maintained.

Abstract

Install, testing and running of a Linux Virtual Server with 2.2.x, 2.4.x, 2.6.x kernels

search the LVS documentation

Hank Leninger’s searchable mailing list archive has moved. It’s now at http://marc.info/?l=linux-virtual-server&w=2.


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