LTTng is an open source tracing framework for Linux.

System-wide insight

LTTng allows to understand the interactions between multiple components of a given system, i.e.:

Tracing all those components with LTTng will produce a unified log of events, providing great insight into the system's behavior. Here's a simplified example of a system trace:

Time App. Event Payload
17:23:05.035454 my-app startup
17:23:05.043948 my-app readConfigBegin path=/home/mole/.my-app/config
17:23:05.044120 linux sys_open pathname=/home/mole/.my-app/config
17:23:05.044120 linux sys_fstat fd=5
ret={st_uid=1002, st_size=4608, ...}
17:23:05.044498 linux sys_read fd=5
17:23:05.046005 linux sys_close fd=5
17:23:05.047948 my-app readConfigEnd
17:23:06.164870 my-app getUser username=joe
17:23:06.251164 java-db doQuery handle=23
query=SELECT * FROM users WHERE...
... ... ... ...

High performance

LTTng is designed from the ground up to provide low overhead tracing on production systems. This is achieved by using techniques such as per-CPU buffering, RCU data structures, a compact and efficient binary format (the Common Trace Format), etc.

LTTng disturbs the traced system as little as possible in order to make tracing of subtle race conditions and rare interrupt cascades possible.

On platforms where resources are limited, such as some Linux embedded systems, LTTng can be used out of the box to help developers pinpoint the sources of hard-to-debug issues.

LTTng offers a new approach to gain insight into your system's behavior.


Whether your target is a small embedded system or a large cloud, LTTng provides flexible configuration options that can accommodate the system's workload. Architectures such as x86, PowerPC, ARM and MIPS are supported, amongst others.

LTTng's tracing session mechanism makes it possible to record multiple traces concurrently with different configuration options. Each user may create and configure as many tracing sessions as needed.

Depending on your specific scenario, you may wish to:


As LTTng is packaged for all major Linux distributions, installing it is done through package managers.

A single tool, the lttng command line interface, is used to control the whole framework.

Multiple ways to view and analyze the traces produced by LTTng exist: GUI, CLI tools, and custom scripts.

LTTng has a lot more to offer. To learn more: