Memcache anomaly

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Symptoms

We had a webserver running smoothly until extreme huge traffic appeared on the bond0 interface shown in cacti. The traffic was near the double of the loadbalancer’s in- and outbound traffic. The memcached was continuously rejecting new connections.

Investigation

Memcache hit/miss ratio was almost perfect 99% / 1%. However … Continue reading

Unindexed queries can be really expensive

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The story happened with a webshop application running on Amazon EC2 microinstances. Actually on two instance. Amazon business model is basically simple, they ask money for only three things: Cpu time, IOPS and network traffic. Everybody (including me) thinks for the first time network traffic will be the bottleneck until … Continue reading