Throttle / Buffer Messages

[symentis-info]

Slack allows only 1 msg. per second per channel (Rate-Limits).

The Appender should buffer messages and send them by a max rate of 1 per second.
If the buffer grows over a defined limit, it may discard messages until the buffer size is below the threshold.

Slack sends HTTP status 429 when rate-limiting occurs. This includes a time when the next call can be made. This should also been taken into account.

There is a risk to get permanently banned. "Continuing to send messages after exceeding a rate limit runs the risk of your app being permanently disabled."