mod_log_slow_events

Introduction

Most activities in Prosody take place within our built-in events framework, for example stanza processing and HTTP request handling, authentication, etc.

Modules are able to execute code when an event occurs, and they should return as quickly as possible. Poor performance (e.g. slow or laggy server) can be caused by event handlers that are slow to respond.

This module is able to monitor how long each event takes to be processed, and logs a warning if an event takes above a certain amount of time, including providing any details about the event such as the user or stanza that triggered it.

The aim is to help debug why a server may not be as responsive as it should be, and ultimately which module is to blame for that.

Configuration

There is a single configuration option:

   -- Set the number of seconds an event may take before
   -- logging a warning (fractional values are ok)
   log_slow_events_threshold = 0.5

Metrics

In addition to the log messages, a new ‘slow_events’ metric will be exported to your configured stats backend (if any).

Compatibility

trunk Works
0.10 Works
0.9 Doesn’t work
0.8 Doesn’t work