Failover and Load Balancing using HAProxy

HAProxy is open source proxy that can be used to enable high availability and load balancing for web applications. It was designed especially for high load projects so it is very fast and predictable, HAProxy is based on single-process model. In this post I’ll describe sample setup of HAProxy: users’ requests are load balanced between two web servers Web1 and Web1, if one of them goes down then all the […]

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Grub Fallback: Boot good kernel if new one crashes

It’s hard to believe but I didn’t know about Grub fallback feature. So every time when I needed to reboot remote server into a new kernel I had to test it on local server to make sure it won’t panic on remote unit. And if kernel panic still happened I had to ask somebody who has physical access to the server to reboot the hardware choose proper kernel in Grub. […]

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