Setting safe: true in the options doesn't guarantee log message getting written

[alexyhkim]

Added safe: true in the options for the MongoDB transport. Then I log a message and throw an error immediately after. Message shows up in console but not mongo. Adding handleExceptions: true also fails to log anything in mongo. I am considering implementing a custom transport with synchronous logging to mongo. Is this necessary, or am I using the transport incorrectly?

[yurijmikhalevich]

As mentioned here winston is a multi-transport async logging library for node.js. So, if you want synchronous logging you may want to use another logging library.
By the way, this issue is related to issue winstonjs/winston#228. The key issue seems to be that WritableStreams do not guarantee flushing on process.exit() or unhandled exception.

[yurijmikhalevich]

Also, look issue #12

[alexyhkim]

Yep, I realize winston is a multi-transport async logging library for node.js. But what is the point of the {safe: true} option?

[yurijmikhalevich]

@alexyhkim log method has an optional callback argument, if you pass {safe: true} option, it will be fired only when data was guarantee written.

[alexyhkim]

When does the callback fire if you don't pass {safe: true}? Because it seemed to fire after data was written without the option as well

[yurijmikhalevich]

@alexyhkim without {safe: true} mongodb-native callback is fired immediately (after sending data to driver) and thus doesn’t make much sense.

[alexyhkim]

Oh okay, thank you for the quick replies.

[yurijmikhalevich]

@alexyhkim you're welcome!