Sysdig is open source, Linux System Troubleshooting Tool: capture system state and activity from a running Linux instance, then save, filter and analyze. Think of it as strace + tcpdump + lsof + awesome sauce. With a little Lua cherry on top.
Sysdig was born from a team’s constant frustration. System level troubleshooting is just way more of a pain than it should be — especially in distributed, virtualized, and cloud-based environments. So they took the lessons they learned while building network monitoring tools like WinPCap and Wireshark and created a new kind of system troubleshooting tool for Linux.
Sysdig captures system calls and other system level events using a linux kernel facility called tracepoints, which means much less overhead than strace.
It then “packetizes” this information, so that you can save it into trace files and filter it, a bit like you would do with tcpdump. This makes it very flexible to explore what processes are doing.
Sysdig is also packed with a set of scripts that make it easier to extract useful information and do troubleshooting.