High-Availability

Want to support HowtoForge? Become a subscriber!
 

Master-Master Replication With MySQL 5 On Fedora 8

Master-Master Replication With MySQL 5 On Fedora 8

This document describes how to set up master-master replication with MySQL 5 on Fedora 8. Since version 5, MySQL comes with built-in support for master-master replication, solving the problem that can happen with self-generated keys. In former MySQL versions, the problem with master-master replication was that conflicts arose immediately if node A and node B both inserted an auto-incrementing key on the same table. The advantages of master-master replication over the traditional master-slave replication are that you don't have to modify your applications to make write accesses only to the master, and that it is easier to provide high-availability because if the master fails, you still have the other master.

Sample Configuration of DRBD On CentOS 4.5

Sample Configuration of DRBD On CentOS 4.5

DRBD is an abbreviation of Distributed Replicated Block Device. DRBD is a block device which is designed to build high-availability clusters. This is done by mirroring a whole block device via (a dedicated) network. You could see it as a network RAID1.

Setting Up A High-Availability Load Balancer (With Failover and Session Support) With HAProxy/Heartbeat On Debian Etch

Setting Up A High-Availability Load Balancer (With Failover and Session Support) With HAProxy/Heartbeat On Debian Etch

This article explains how to set up a two-node load balancer in an active/passive configuration with HAProxy and heartbeat on Debian Etch. The load balancer sits between the user and two (or more) backend Apache web servers that hold the same content. Not only does the load balancer distribute the requests to the two backend Apache servers, it also checks the health of the backend servers. If one of them is down, all requests will automatically be redirected to the remaining backend server. In addition to that, the two load balancer nodes monitor each other using heartbeat, and if the master fails, the slave becomes the master, which means the users will not notice any disruption of the service. HAProxy is session-aware, which means you can use it with any web application that makes use of sessions (such as forums, shopping carts, etc.).

Setting Up A High-Availability Load Balancer (With Failover and Session Support) With Pound/Keepalived On Debian Etch

Setting Up A High-Availability Load Balancer (With Failover and Session Support) With Pound/Keepalived On Debian Etch

This article explains how to set up a two-node load balancer in an active/passive configuration with Pound and keepalived on Debian Etch. The load balancer sits between the user and two (or more) backend Apache web servers that hold the same content. Not only does the load balancer distribute the requests to the two backend Apache servers, it also checks the health of the backend servers. If one of them is down, all requests will automatically be redirected to the remaining backend server. In addition to that, the two load balancer nodes monitor each other using keepalived, and if the master fails, the slave becomes the master, which means the users will not notice any disruption of the service. Pound is session-aware, which means you can use it with any web application that makes use of sessions (such as forums, shopping carts, etc.).

Merging Multiple Apache Access Logs Into One Overall Access Log

Merging Multiple Apache Access Logs Into One Overall Access Log

Let's assume you have a web application that runs of a cluster of Apache nodes. Each node generates its own Apache access log from which you can generate page view statistics with tools such as Webalizer or AWStats. Obviously you do not want to have page view statistics for each Apache node, but overall page view statistics. To achieve this, we must merge the access logs from each node into one overall access log that we can then feed into Webalizer or AWstats. There is a Perl script called logresolvemerge.pl (part of the AWStats package) that can do this for us.

Setting Up A High-Availability Load Balancer (With Failover and Session Support) With HAProxy/Keepalived On Debian Etch

Setting Up A High-Availability Load Balancer (With Failover and Session Support) With HAProxy/Keepalived On Debian Etch

This article explains how to set up a two-node load balancer in an active/passive configuration with HAProxy and keepalived on Debian Etch. The load balancer sits between the user and two (or more) backend Apache web servers that hold the same content. Not only does the load balancer distribute the requests to the two backend Apache servers, it also checks the health of the backend servers. If one of them is down, all requests will automatically be redirected to the remaining backend server. In addition to that, the two load balancer nodes monitor each other using keepalived, and if the master fails, the slave becomes the master, which means the users will not notice any disruption of the service. HAProxy is session-aware, which means you can use it with any web application that makes use of sessions (such as forums, shopping carts, etc.).

Setting Up Master-Master Replication With MySQL 5 On Debian Etch

Setting Up Master-Master Replication With MySQL 5 On Debian Etch

Since version 5, MySQL comes with built-in support for master-master replication, solving the problem that can happen with self-generated keys. In former MySQL versions, the problem with master-master replication was that conflicts arose immediately if node A and node B both inserted an auto-incrementing key on the same table. The advantages of master-master replication over the traditional master-slave replication are that you don't have to modify your applications to make write accesses only to the master, and that it is easier to provide high-availability because if the master fails, you still have the other master.

Apache: Creating A Session-Aware Loadbalancer Using mod_proxy_balancer (Debian Etch)

Apache: Creating A Session-Aware Loadbalancer Using mod_proxy_balancer (Debian Etch)

Since Apache 2.1, a new module called mod_proxy_balancer is available which lets you turn a system that has Apache installed into a loadbalancer. This loadbalancer retrieves requested pages from two or more backend webservers and delivers them to the user's computer. Users get the impression that they deal with just one server (the loadbalancer) when in fact there are multiple systems behind the loadbalancer that process the users' requests. By using a loadbalancer, you can lower the load average on your webservers. One important feature of mod_proxy_balancer is that it can keep track of sessions which means that a single user always deals with the same backend webserver. Most websites are database-driven nowadays with user logins etc., and you'd get weird results if a user logs in on one backend webserver, and then his next request goes to another backend webserver, meaning he'd get logged out again. You can avoid this by using mod_proxy_balancer's session-awareness.

How To Back Up MySQL Databases Without Interrupting MySQL

How To Back Up MySQL Databases Without Interrupting MySQL

This article describes how you can back up MySQL databases without interrupting the MySQL service. Normally, when you want to create a MySQL backup, you either have to stop MySQL or issue a read lock on your MySQL tables in order to get a correct backup; if you don't do it this way, you can end up with an inconsistent backup. To get consistent backups without interrupting MySQL, I use a little trick: I replicate my MySQL database to a second MySQL server, and on the second MySQL server I use a cron job that creates regular backups of the replicated database.

How To Set Up A Loadbalanced High-Availability Apache Cluster

How To Set Up A Loadbalanced High-Availability Apache Cluster

This tutorial shows how to set up a two-node Apache web server cluster that provides high-availability. In front of the Apache cluster we create a load balancer that splits up incoming requests between the two Apache nodes. Because we do not want the load balancer to become another "Single Point Of Failure", we must provide high-availability for the load balancer, too. Therefore our load balancer will in fact consist out of two load balancer nodes that monitor each other using heartbeat, and if one load balancer fails, the other takes over silently.

first page
previous page
7
next page
last page
XML feed
"Facebook" is a registered trademark of Facebook, Inc. All rights reserved.