There is a low, but significant number of mediawiki errors on query execution with the above error:
Wikimedia\Rdbms\Database::close 10.192.32.168 2014 Commands out of sync; you can't run this command now (10.192.32.168) COMMIT
e.g.:
{ "_index": "logstash-2018.09.14", "_type": "mediawiki", "_id": "AWXX_3jKo1GdFyIETwgn", "_version": 1, "_score": null, "_source": { "server": "en.wikipedia.org", "db_server": "10.192.32.168", "wiki": "enwiki", "channel": "DBQuery", "type": "mediawiki", "error": "Commands out of sync; you can't run this command now (10.192.32.168)", "http_method": "GET", "@version": 1, "host": "mw2274", "shard": "s1", "sql1line": "COMMIT", "fname": "Wikimedia\\Rdbms\\Database::close", "errno": 2014, "unique_id": "W5ulhArAMGAAALdEtv8AAAHQ", "method": "Wikimedia\\Rdbms\\Database::makeQueryException", "level": "ERROR", "ip": "10.192.16.136", "mwversion": "1.32.0-wmf.20", "message": "Wikimedia\\Rdbms\\Database::close\t10.192.32.168\t2014\tCommands out of sync; you can't run this command now (10.192.32.168)\tCOMMIT", "normalized_message": "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}", "url": "/w/index.php?oldid=848654409&redirect=no", "tags": [ "syslog", "es", "es" ], "reqId": "W5ulhArAMGAAALdEtv8AAAHQ", "referrer": null, "@timestamp": "2018-09-14T12:12:48.000Z", "db_name": "centralauth", "db_user": "wikiuser" }, "fields": { "@timestamp": [ 1536927168000 ] }, "sort": [ 1536927168000 ] }
My guess is that a COMMIT is tried in a non-started transaction (or it is, but connection is lost) See below T204346#4584159 for a proper analysis.
The commands seem to happen (at least) on the following url:
https://en.wikipedia.org/w/index.php?oldid=854160404
And indeed that doesn't seem to load for me.
First occurrence seemed to happen on 2018-09-11T12:27:17, before the dc switch.