heapdump-signal

heapdump-signal
===

Replacement for node-heapdump (native module) to trigger the built-in Node V8 API to write a heapdump upon receiving SIGUSR2.

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Require the module somewhere in your code.

require('heapdump-signal');

On UNIX platforms, you can force a snapshot by sending the node.js process
a SIGUSR2 signal:

$ kill -USR2

If you want to respond to a different signal or write to a different path, use the v8.writeHeapSnapshot API instead, it's easy!

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Open Google Chrome and
press F12 to open the developer toolbar.

Go to the Memory tab, right-click in the tab pane and select
Load profile....

Select the dump file and click Open. You can now inspect the heap snapshot
at your leisure. Some snapshots may take a long time to load, on the order of
minutes or even hours.

Note that Chrome will refuse to load the file unless it has the .heapsnapshot
extension.

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On UNIX systems, the rule of thumb for creating a heap snapshot is that it
requires memory twice the size of the heap at the time of the snapshot.
If you end up with empty or truncated snapshot files, check the output of
dmesg; you may have had a run-in with the system's OOM killer or a resource
limit enforcing policy, like ulimit -u (max user processes) or ulimit -v
(max virtual memory size).