UPDATE: The price for spot instances has risen and the value of LiteCoin has dropped. The combination of these two factors makes LiteCoin mining on EC2 likely to be unprofitable at the present time. I'm sure a lot of people will be paying close attention paid to the spot prices now though…
I've been talking a lot about zero-downtime deployments with MySQL as your database backend (including schema changes/migrations!) recently.
I gave a 45 minute presentation called Zero Downtime Deployments with Database Migrations, from a DevOps conference that Vladimir Vuksan and I organized back in November 2012.
Using low-overhead virtualization methods like chroots, containers, etc. is a great way to gain most of the benefits of virtualization without the overhead of traditional hypervisor-based virtualization. Since 2011, lxc has become the standard, kernel-integrated lightweight virtualization method.
Before 2010 comes to a close, be sure to check out the sysadmin's Advent calendar, SysAdvent! Last year, I contributed an article about ATA over Ethernet (AoE), and I wrote about Website Performance Optimization this year.
HAProxy is a great load balancer; however, it doesn't natively terminate SSL connections. Fortunately, stunnel can terminate SSL connections and seamlessly forward them to HAProxy. To be able to log the client's IP address, we'll need to patch stunnel to provide X-Forwarded-For headers to HAProxy.
I recently migrated CompleteFusion to a new hosting provider, which meant switching from a Xen-based VPS to OpenVZ. Although OpenVZ VPS hosting is generally much less expensive, it often lacks swap space and requires special consideration of memory usage. Running OpenSSH, MySQL, and Apache2 with mod_php5 caused out of memory problems, even with 512MB RAM.