natlownes

bazel query cheatsheet

which packages depend on qtdb lib?

bazel query 'rdeps(..., //vistar/geo/qtdb:go_default_library)' --output package 

which packages does qtdb depend on?

wonjun27

Scalr

http://highscalability.com/blog/2010/3/22/7-secrets-to-successfully-scaling-with-scalr-on-amazon-by-se.html
http://stackoverflow.com/questions/10061843/how-to-convert-linux-cron-jobs-to-the-amazon-way

Cron Jobs Are Hard To Distribute

Watch out when scaling out instances with cron jobs on them. Cron jobs aren't designed for the cloud. If the machine image holding your cron job scales out to 20 instances, your cron job will be executed 20 times more often.

This is fine if the scope of your cron job is limited to the instance itself, but if the scope is larger, the above becomes a serious problem. And if you single out a machine to run those cron jobs, you run the risk of not having it executed if that machine goes down.

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD