(No version information available, might only be in SVN)
Logging can be used to get detailed information about what the driver is doing. The logging mechanism as used by MongoLog emits all log messages as a PHP notice. Depending on the server interface that you use, that means that they will either be sent to strerr (with PHP-CLI), or otherwise to the web server's error log. In order for log messages to be output by PHP their level (E_NOTICE) does need to be configured to be shown. That means the E_NOTICE bit needs to be part of PHP's error_reporting level and that display_errors is set to 1.
Logging is turned off, by default. This class allows you to turn on specific levels of logging for specific parts of the driver. Some examples:
<?php
// print every log message possible
MongoLog::setLevel(MongoLog::ALL); // all log levels
MongoLog::setModule(MongoLog::ALL); // all parts of the driver
// print significant events about replica set failover
MongoLog::setLevel(MongoLog::INFO);
MongoLog::setModule(MongoLog::RS);
// print info- and server tuning-level events from replica sets and connection pooling
MongoLog::setLevel(MongoLog::INFO|MongoLog::FINE);
MongoLog::setModule(MongoLog::RS|MongoLog::POOL);
?>
These constants can be used by both MongoLog::setLevel() and MongoLog::setModule().
MongoLog::NONE
MongoLog::ALL
These constants can be used by MongoLog::setLevel().
MongoLog::WARNING
MongoLog::INFO
MongoLog::FINE
These constants can be used by MongoLog::setModule().
MongoLog::IO
MongoLog::PARSE
MongoLog::POOL
MongoLog::RS
MongoLog::SERVER