Currently suffering around 60 of these per second:
```
{
"_index": "logstash-2015.06.29",
"_type": "hhvm",
"_id": "rOLcen60QZ6gFKCtfvhjBQ",
"_score": null,
"_source": {
"message": "Fatal error: Call to undefined method SearchResultSet::addInterwikiResults() in /srv/mediawiki/php-1.26wmf11/extensions/CirrusSearch/includes/CirrusSearch.php on line 159",
"@version": "1",
"@timestamp": "2015-06-29T12:12:01.000Z",
"type": "hhvm",
"host": "mw1145",
"priority": 11,
"timestamp": "Jun 29 12:12:01",
"logsource": "mw1145",
"program": "hhvm",
"severity": 3,
"facility": 1,
"facility_label": "user-level",
"severity_label": "Error",
"level": "Fatal",
"tags": [
"syslog",
"es",
"normalized_message_untrimmed"
],
"normalized_message": "Fatal error: Call to undefined method SearchResultSet::addInterwikiResults() in /srv/mediawiki/php-1.26wmf11/extensions/CirrusSearch/includes/CirrusSearch.php on line 159"
},
"sort": [
1435579921000
]
}
```