useful systems

• http reverse proxies / load balancers
  • nginx
  • [http://www.haproxy.org/ HAProxy]
• message queuing
  • http://www.celeryproject.org/
  • http://www.rabbitmq.com/
  • Mosquitto (MQTT)

DB

• [https://wiki.postgresql.org/wiki/PgBouncer 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>