On the beta cluster, Parsoid runs on the instance deployment-parsoid05.eqiad.wmflabs. I noticed the four parsoid process eating all the CPU.
Looking at the log file at /data/project/parsoid/parsoid.log tgere are a bunch of socket timeout errors against eswiki/wikidatawiki db (at least):
{ "name":"parsoid", "hostname":"deployment-parsoid05", "pid":22036, "level":40, "logType":"warning/api/esockettimedout", "wiki":"wikidatawiki", "title":"Q63760", "oldId":null, "reqId":"572eeab6459c44ffbf2e7a439858cfcd", "msg":"Failed API request, {\"error\":{\"code\":\"ESOCKETTIMEDOUT\"},\"retries-remaining\":1}", "longMsg":"Failed API request,\n{\"error\":{\"code\":\"ESOCKETTIMEDOUT\"},\"retries-remaining\":1}", "time":"2015-04-28T15:27:21.925Z", "v":0 }
https://logstash-beta.wmflabs.org/ gives a bit more informations using the filters:
field : _type == value : parsoid logType == query : "warning/api/etimedout"