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Message-ID: <48580C64.40806@gmail.com>
Date: Tue, 17 Jun 2008 12:11:32 -0700
From: Brad Schick <schickb@gmail.com>
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To: couchdb-user@incubator.apache.org
Subject: Bad write performance
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I am seeing very poor write performance running CouchDB on Ubuntu Linux
8.04. I built CouchDB from source about a week ago, and I am using the
Python wrapper to access it all on localhost.

I am trying to add over 90,000 documents (each is about 400 bytes) and
finding that I can only add about 16 documents per second. And while
this is happening, my CPU is about 75% idle. I saw this discussion of
the Nagle algorithm
(http://www.cmlenz.net/archives/2008/03/python-httplib-performance-problems),
but I don't think that is the issue since mochiweb_sockert_server.erl
now has {nodelay, true}. I've also tried adding nodelay on the client
side and that didn't help.

Profiling the client app I see that almost all of the time is spent in
httplib.py:getresponse. So there is some bottleneck between the client
and server that is not CPU bound. Any suggestions? I know very little
about Erlang, is there an easy way to profile CouchDB?

-Brad