Manual:MonologSpi.php

is a service provider interface for use with  that creates Monolog loggers.

Requirements
requires Monolog to be installed and available to your wiki. One way to do this is via composer:

Details
Monolog allows a large amount of flexibility in configuring the destination, format and contents of log events. The basic building blocks of a Monolog configuration are:


 * Loggers
 * A logger is a named logging channel. The name of the channel is used to determine what configuration to apply to messages sent to that channel.


 * Processors
 * A processor adds or modifies contextual information of a log event.
 * Including the  handler is recommended to make Monolog expand PSR-3   placeholders in the message body.
 * The MediaWiki provided  processor will add   and   to the log event.


 * Handlers
 * Each logger should have one or more handlers attached to it.
 * writes log events to a file or PHP stream.
 * MediaWiki's  can take the same file or UDP endpoint syntax as used by $wgDebugLogGroups.


 * Formatters
 * The formatters normalize and format incoming records for the handlers. If not specified in the config, a default formatter will be selected by the handler.
 * mimics the legacy log message formatting of,  ,   and   global functions by delegating the formatting to.

Example from MediaWiki-Vagrant's "elk" role
You can setup logging to an Elasticsearch, Logstash and Kibana (ELK) log aggregation stack in MediaWiki-Vagrant by enabling the  role:

This role configures the wiki to log to local files and also to feed Logstash via an intermediate Redis queue.