High Availability and Load Balancing for MySQL

The constantly growing demands for information networks require confidentiality and resources that are always available. Using existing techniques to deal with increasing information flow, masses of information have to pass through what seem to be eternal bottlenecks. An enterprise will function only as fast as the information flows. In practice, there are two possible solutions to achieving continuous availability and load balancing. More traditional method is based on front-end hardware, which is designed to handle the high availability and load balancing of the target applications, but this provides only a partial solution to the problem. Low-cost, effective software-only solutions that solve the large-scale branching points problems in the back-end servers become a reality.

Emic Application Cluster (EAC) for MySQL offers software-only based dynamic load balancing for MySQL databases. Load balancing is usually done by evenly distributing IP address space, including port numbers, to all the cluster nodes. To implement this solid distribution method, EAC uses bit masks. Client's IP address and port number is XOR'ed against a bit mask and result tells the node whether or not it should serve the client in question. If not, node will immediately drop all incoming packets by using its fast low-level drop-down algorithm. At same time, another MySQL server is accepting these packets and routes them up to its TCP/IP stack. This technique will distribute average load evenly for all the nodes. Bit masks are redistributed between clustered MySQL servers when a node is joining or leaving the cluster, or if load-level increases significantly in any particular cluster node. EAC load balancer ensures high scalability for system performance and protection against time-limited peak load that can be now handled in an economical way. Load balancer, which is running in clustered nodes themselves, removes the need for vertical based, expensive dedicated network load balancers from vendors such as F5 Networks and Cisco. Even open source Linux virtual server (LVS) is an additional expense, since it is a potential single-point-of-failure without a redundant pair, thus increasing hardware expenses. Emic Networks offers software products for MySQL that meet the requirements of the enterprise-level scalability and availability requirements providing:

- Load balancing of MySQL database servers
- Dynamic load balancing mode, which uses server's real resources
- Real-time logging & monitoring
- Fast and reliable synchronous replication
- High availability framework

For more information about EAC for MySQL, visit
http://www.emicnetworks.com/download/pdf/eac_mysql_whitepaper.pdf. Or
download a free evaluation version at
http://www.emicnetworks.com/download/download_software.html