IO activity is not monitored, there's only one db on the couchdb instance and the described job is the only activity executed on this machine. Delaying the first request on the database url by 30 seconds did actually prevent the problem from happening again. So the issue seems to happen specifically at the moment right after compaction is started. The database is about 7GB big once compressed, the server is hosted on ec2 with the database directory placed on his own dedicated ephemeral storage.
Thanks, Paolo On Fri, Oct 14, 2011 at 9:05 PM, Paul Davis <[email protected]> wrote: > Do you monitor IO activity or system responsiveness when you're doing > this. I've seen some compactions wallop a system when it switches over > due to removing large old files and such. It doesn't sound like this > is big enough for that case but it might be something worth checking. > > On Fri, Oct 14, 2011 at 3:41 AM, Paolo Negri <[email protected]> wrote: >> Dear list, >> >> We have a script that does the following (strictly sequentially) >> >> 1) update 300K docs in a db >> 2) launch compaction of the db >> 3) poll at a 30 sec frequency http://127.0.0.1:5984/database to know >> when compaction completed >> >> Last night we got a timeout error during 3, we think that this might >> be because the first polling (GET http://127.0.0.1:5984/database) is >> done right after triggering compaction >> >> I thought the dev team might be interested in knowing that this is happening >> >> There's no other activity on the couchdb instance other than what >> described in this email. >> >> ERROR unexpectd response checking compaction db: {ok,"500", >> [{"Server", >> >> "CouchDB/1.3.0a-74613f5-git (Erlang OTP/R14B04)"}, >> {"Date", >> "Fri, 14 Oct 2011 >> 01:46:37 GMT"}, >> {"Content-Type", >> "text/plain; >> charset=utf-8"}, >> {"Content-Length","350"}, >> {"Cache-Control", >> "must-revalidate"}], >> >> <<"{\"error\":\"{timeout,{gen_server,call,[<0.21934.9>,{open_ref_count,<0.4090.13>}]}}\",\"reason\":\"{gen_server,call,\\n >> [couch_server,\\n {open,<<\\\"backup\\\">>,\\n >> [{user_ctx,\\n {user_ctx,null,\\n >> [<<\\\"_admin\\\">>],\\n <<\\\"{couch_httpd_auth, >> default_authentication_handler}\\\">>}}]},\\n infinity]}\"}\n">>} >> >> >> Thanks, >> >> Paolo >> > -- Engineering http://www.wooga.com | phone +49-30-8962 5058 | fax +49-30-8964 9064 wooga GmbH | Saarbruecker Str. 38 | 10405 Berlin | Germany Sitz der Gesellschaft: Berlin; HRB 117846 B Registergericht Berlin-Charlottenburg Geschaeftsfuehrung: Jens Begemann, Philipp Moeser
