node-usdt
Create USDT probes and instrument your application easily and without rebuilding Node.
Dependencies
At the moment this module only runs on Linux and requires libstapsdt to be installed to create runtime probes.
Ubuntu 16.04
To install libstapsdt, run:
sudo add-apt-repository ppa:sthima/osssudo apt-get updatesudo apt-get install libstapsdt0 libstapsdt-dev
Other
Build from libstapsdt.
Install
npm install usdt
Example
The following code will create a probe named firstProbe
.
const USDT = ; const provider = "nodeProvider";const probe1 = provider;provider;let countdown = 10; { console; ifcountdown <= 0 console; provider; probe1;} ;
You can then trace this probe with any tool able to trace Systemtap's probes. Here's an example with eBPF/bcc:
sudo trace -p $(pgrep node) 'u::firstProbe "%d - %s", arg1, arg2'