:small_orange_diamond: strace - diagnostic, debugging and instructional userspace utility for Linux.
:small_orange_diamond: sysdig - system exploration and troubleshooting tool with first class support for containers.
+ :small_orange_diamond: glances - cross-platform system monitoring tool written in Python.
:small_orange_diamond: lsof - displays in its output information about files that are opened by processes.
:small_orange_diamond: FlameGraph - stack trace visualizer.
:small_orange_diamond: lsofgraph - small utility to convert Unix lsof output to a graph showing FIFO and UNIX interprocess communication.