DTrace
also: Dynamic Tracing, Dtrace, DTracer
DTrace is a dynamic tracing framework that allows real-time observation and analysis of kernel and application behavior without stopping or recompiling the system.
DTrace (Dynamic Tracing) is a powerful debugging and performance analysis tool originally developed by Sun Microsystems for Solaris. It enables administrators and developers to instrument live systems by placing probes at thousands of points in the kernel and user applications, capturing detailed information about system activity as it happens.
DTrace uses a simple scripting language (also called DTrace) to define what to trace and how to process the collected data. For example, you can track every system call made by a specific process, measure function execution time, or count events without modifying code or restarting services:
dtrace -n 'syscall:::entry { @[execname] = count(); }'While DTrace is native to Solaris/illumos systems, it has been ported to some Linux distributions (notably with the systemtap and bpftrace projects offering similar functionality on Linux). It is invaluable for production troubleshooting when you need detailed visibility into system behavior with minimal overhead.