useful systems

• http reverse proxies / load balancers
  • nginx
  • HAProxy
• message queuing
  • http://www.celeryproject.org/
  • http://www.rabbitmq.com/

passwords

If you have an open system and base password checks on hashes then it's may be an issue that somebody can guess a password by just trying to find a word that will produce the same hash as for somebody else. So the security also is based on how long it takes to do a brood force attach on such hashes.

• And so it might be helpful to know that do a hash in python with sha1 you can calculate about 50000 more hashes of passwords then with bcrypt.*

(see here at around 16:30)

DB

• PostgreSql connection pooling

dd command with progress

• start the dd command as intended
• open another shell
• find dd command process id (e.g. via pgrep -l '^dd$')
• send USR1 signal via kill -USR1 <processID>
  • or send it regularly via watch -n 10 kill -USR1 <processID>