PUBLIC MARKS from camel with tags debian & application

MySQLTuner is a script written in Perl that will assist you with your MySQL configuration and make recommendations for increased performance and stability. Within seconds, it will display statistics about your MySQL installation and the areas where it can be improved. It’s key to remember that MySQLTuner is a script which can assist you with your server, but it is not the solution to a badly performing MySQL server. The best performance gains come from a thorough review of the queries sent to the server, and an evaluation of the MySQL server itself. A qualified developer in your application’s programming or scripting language should be able to work with a MySQL database administrator to find improvements for your server. Once the server and application are optimized well, you may need to consider hardware upgrades to the physical server itself. This is a really useful tool for helping to optimize MySQL performance.Understanding the various my.cnf variables and how they affect performance can seem really complicated but this tool takes some of the pain away and makes it easier to understand the effects of each variable.It is especially useful to be able to see the global memory usage, memory usage per thread and the maximum possible memory usage - that is really valuable information that is otherwise complex to calculate.

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.). From the HAProxy web site: "HAProxy is a free, very fast and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It is particularly suited for web sites crawling under very high loads while needing persistence or Layer7 processing. Supporting tens of thousands of connections is clearly realistic with todays hardware. Its mode of operation makes its integration into existing architectures very easy and riskless, while still offering the possibility not to expose fragile web servers to the Net."

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.).