Stack traces from node are sometimes truncated. How can I see the full error? - node.js

Question

I have a route that (deliberately) crashes my node app. When I visit that route, I get a proper log of the crash:
/Users/me/Documents/myapp/routes/index.js:795
global.fakeMethod();
^
TypeError: global.fakeMethod is not a function
at null._onTimeout (/Users/me/Documents/myapp/routes/index.js:795:11)
at Timer.listOnTimeout (timers.js:92:15)
However when I run that same code under systemd, the error is truncated. It
May 17 10:03:56 a.myapp.com www[28766]: /var/www/myapp/routes/index.js:795
May 17 10:03:56 a.myapp.com systemd[1]: myapp.service: main process exited, code=exited, status=1/FAILURE
May 17 10:03:56 a.myapp.com systemd[1]: Unit myapp.service entered failed state.
May 17 10:03:56 a.myapp.com systemd[1]: myapp.service failed.
May 17 10:03:56 a.myapp.com systemd[1]: myapp.service holdoff time over, scheduling restart.
How can I make systemd / journald log the full error?
Update: testing with systemd-cat, I have made a multiline file and logging it works:
cat file.txt | systemd-cat
results in:
Mar 02 09:51:25 a.certsimple.com unknown[31600]: line one
Mar 02 09:51:25 a.certsimple.com unknown[31600]: line two
Mar 02 09:51:25 a.certsimple.com unknown[31600]: line three

Answer 1

My best bet is it has something to do with stderr/stdout not being flushed before your application terminates.
Is there any way to tell your application to print the stack trace with synchronous syslog protocol instead of printing on the stdout.

Answer 2

This is not a systemd issue. It's a [node issue](https://github.com/nodejs/node/issues/6456
): node's process.exit() will always exit ASAP. process.exitCode() will flush buffers.
See the main issue for node v6 at: https://github.com/nodejs/node/issues/6456
As a workaround I'm wrapping process.exit():
var wrap = require('lodash.wrap');
var log = console.log.bind(console)
var RESTART_FLUSH_DELAY = 3 * 1000
process.exit = wrap(process.exit, function(originalFunction) {
log('Waiting', RESTART_FLUSH_DELAY, 'for buffers to flush before restarting')
setTimeout(originalFunction, RESTART_FLUSH_DELAY)
});
process.exit(1);