sentrycore

Overview ¶

sentrycore provides a Sentry sink, that captures errors passed to the logger with the log.Error function if and only if the log level is superior or equal to Error.

In order to not slow down logging when it's not necessary:

a) the underlying zapcore.Core is only processing logging events on Error and above levels.

b) consuming log events and processing them for sentry reporting are both asynchronous. This deflects most of the work into the processing go routine and leverage Sentry's client ability to send reports in batches.

In the eventuality of saturating the events buffer by producing errors quicker than we can produce them, they will be purely dropped.

In order to avoid losing events, the events are continuously sent to Sentry and don't need to be explicitly flushed. If asked explicitly to be flushed as part of the zapcore.Core interface, the Sentry sink will try to consume all log events within a reasonable time before shutting down the consumer side, and will then submit them to Sentry.

Flushing is only called in the final defer function coming from our logging API, meaning that will only happen when a service is shutting down.

In the eventuality where we are submitting events faster than we could consume then, the upper bound is a large buffered channel, which should be enough to accumulate errors while we're asynchronously reporting them to Sentry.

It would be nice to be able to know if we're dropping errors, but that would create a circular dependency from the sink toward the logger, so for now, they're just silently discarded.