Joshua Jacobs
This morning I read an article on Linux Magazine (Ten Things You Didn’t Know Apache 2.2 Could Do | Linux Magazine). Two features really jumped out at me.
Server Name Indication (SNI): Allows a single IP address to support multiple SSL certificates. This is great because not only does it usually cost more for more IPs, but it starts to get harder to manage. Documentation for this functionality is in the docs wiki, at http://wiki.apache.org/httpd/NameBasedSSLVHostsWithSNI.
mod_proxy_balancer: Allows apache to function as a front-end load balancer. More docs are here http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html. I’m imagining using this to boost performance and reliability LAMP apps, in particular Moodle. Imagine this configuration:
Load Balancer: Dual OpenBSD with CARP shared IP addresses, running Apache 2.2 and mod_proxy_balancer. This way the proxy is always fail-safe.
Application Servers: VMware installation, perhaps ESXi and multiple CentOS running Apache and PHP, etc.
SAN: Dedicated file storage to share application files, configurations, all date but not database.
Database Servers: WMware or straight installation on hardware running CentOS and MySQL or PostgreSQL. Two servers running with database replication should work.
Summary: Fault tolerant, high availability configuration using standard apps with little to no “cleverness” or kernel. I really want to try this!
Question for readers:
Can anyone experienced with mod_proxy_balancer tell me if it would support geographic load balancing?
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