Session handler checking for memcached uses memcache functions.

[nhoobin]

When checking the status of the session handler, it is hard coded to use '\core\session\memcached'.

moodle-tool_heartbeat/index.php

Line 111 in fa97887

$sessionhandler = (property_exists($CFG, 'session_handler_class') && $CFG->session_handler_class == '\core\session\memcached');

During the actual check, it uses a function 'memcache_connect()' which belongs to the php module 'memcache'.

moodle-tool_heartbeat/index.php

Line 117 in fa97887

memcache_connect($memcache[0], $memcache[1], 3);

If the server is not using the memcache extension a fatal error will be thrown.

Additionally the Moodle error handling has changed with PHP7 https://docs.moodle.org/dev/Moodle_and_PHP7#Exception_and_Throwable and diagnosing that there is an issue with the previous code will return a HTTP status code 500.