Setting it as low because I think this is a very specific query which very specific parameters that only few users executed. It is failing on commons and has been observed just twice failing over 2344 times.
{
"_index": "logstash-2015.07.29",
"_type": "mediawiki",
"_id": "AU7Y3YNDQ7NQKcKbniwk",
"_score": null,
"_source": {
"message": "MIMEsearchPage::reallyDoQuery\t10.64.16.31\t2013\tLost connection to MySQL server during query (10.64.16.31)\tSELECT 6 AS namespace,img_name AS title,img_name AS value,img_size,img_width,img_height,img_user_text,img_timestamp FROM `image` WHERE img_major_mime = 'image' AND img_media_type IN ('BITMAP','DRAWING','AUDIO','VIDEO','MULTIMEDIA','UNKNOWN','OFFICE','TEXT','EXECUTABLE','ARCHIVE') AND img_minor_mime = 'jpeg' LIMIT 3180500,501 ",
"@version": 1,
"@timestamp": "2015-07-29T08:11:12.447Z",
"type": "mediawiki",
"host": "mw1252",
"level": "ERROR",
"tags": [
"syslog",
"es",
"es",
"normalized_message_trimmed"
],
"channel": "wfLogDBError",
"url": "/w/index.php?title=Special:MIMESearch/image/jpeg&limit=500&offset=3180500",
"ip": "10.64.0.104",
"http_method": "GET",
"server": "commons.wikimedia.org",
"referrer": null,
"uid": "80bb6f5",
"process_id": 13345,
"wiki": "commonswiki",
"db_server": "10.64.16.31",
"db_name": "commonswiki",
"db_user": "wikiuser",
"method": "DatabaseBase::reportQueryError",
"errno": 2013,
"error": "Lost connection to MySQL server during query (10.64.16.31)",
"sql1line": "SELECT 6 AS namespace,img_name AS title,img_name AS value,img_size,img_width,img_height,img_user_text,img_timestamp FROM `image` WHERE img_major_mime = 'image' AND img_media_type IN ('BITMAP','DRAWING','AUDIO','VIDEO','MULTIMEDIA','UNKNOWN','OFFICE','TEXT','EXECUTABLE','ARCHIVE') AND img_minor_mime = 'jpeg' LIMIT 3180500,501 ",
"fname": "MIMEsearchPage::reallyDoQuery",
"normalized_message": "MIMEsearchPage::reallyDoQuery\t10.64.16.31\t2013\tLost connection to MySQL server during query (10.64.16.31)\tSELECT 6 AS namespace,img_name AS title,img_name AS value,img_size,img_width,img_height,img_user_text,img_timestamp FROM `image` WHERE img_major_"
},
"sort": [
1438157472447
]
}