Production Servers

Generating a flamegraph can be quite intense on CPU and memory, if we have restricted resources we should generate the flamegraph in two pieces.

First we can use the --collect-only flag to purely capture stacks.

0x --collect-only my-app.js  #0x on the server

Press ctrl+c when ready, this will create the usual profile folder, holding one file, that stacks.$PID.out file.

Now we need to transfer the stacks file from our production server to our local dev machine.

Let's say the pid was 7777, we can generate the flamegraph locally with

0x --visualize-only 7777.0x # create a flamegraph.html in 7777.0x