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Date: Fri, 23 Mar 2012 11:34:42 +0000
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Subject: Re: Why are reads from CouchDB so slow? (1.5MB/s or thereabouts)
From: Jonathan Williamson <jon@netcopy.co.uk>
To: user@couchdb.apache.org
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# time curl http://localhost:5984/
{"couchdb":"Welcome","version":"1.1.1"}

real	0m0.012s
user	0m0.000s
sys	0m0.000s


On Fri, Mar 23, 2012 at 11:31 AM, Jason Smith <jhs@iriscouch.com> wrote:
> Useful as well would be the response time for:
>
> =A0 =A0curl http://localhost:5984/
>
> To get a baseline for CouchDB's raw HTTP response time, with no i/o.
>
> On Fri, Mar 23, 2012 at 11:21 AM, CGS <cgsmcmlxxv@gmail.com> wrote:
>> ...also, it would be nice to know how you inserted the documents and if
>> they have attachments (at that size, I suppose they have). Could you als=
o
>> provide a result from ping 127.0.0.1 for response time fluctuations?
>>
>> CGS
>>
>>
>>
>>
>> On Fri, Mar 23, 2012 at 12:16 PM, Jason Smith <jhs@iriscouch.com> wrote:
>>
>>> Hi, Jonathan.
>>>
>>> Can we start by identifying how fast you think **is** reasonable. What
>>> speeds were you expecting? And on what grounds do you base that
>>> expectation?
>>>
>>> (For example, perhaps connecting and fetching one row from MySQL?)
>>>
>>> On Fri, Mar 23, 2012 at 11:06 AM, Jonathan Williamson <jon@netcopy.co.u=
k>
>>> wrote:
>>> > Hi everyone,
>>> >
>>> > I posted this question on Stack Overflow and Jason Smith suggested I
>>> > try this group instead.
>>> >
>>> >> I have a CouchDB (1.1.1) server running that contains a lot of
>>> documents in the 400-600KB size range.
>>> >>
>>> >> If I time fetching a full document from the database (not from a vie=
w,
>>> just the raw document) it takes 200-400ms to complete which equates to
>>> around 1.5MB/s throughput.
>>> >>
>>> >> If I write the same data to raw files on disk they load in 10-20ms
>>> (around 25-50 MB/s).
>>> >>
>>> >> I'd expect CouchDB to have some overhead, but an order of magnitude
>>> (and some) seems crazy for what is essentially a read!
>>> >>
>>> >> Can anyone shed some light onto why this might be the case?
>>> >>
>>> >> Update: As requested below, a timing from curl:
>>> >>
>>> >> # time curl http://localhost:5984/[dbname]/[documentname]
>>> >>
>>> >> real =A0 =A00m0.684s
>>> >> user =A0 =A00m0.004s
>>> >> sys =A0 =A0 0m0.020s
>>> >>
>>> >> The fetched document was 642842 bytes. I've tested it on both a
>>> standard 1TB harddisk and an EC2 instance (EBS volume) with similar res=
ults.
>>> >
>>> > There was some discussion about the post which can be found here:
>>> >
>>> http://stackoverflow.com/questions/9807200/why-are-reads-from-couchdb-s=
o-slow-1-5mb-s-or-thereabouts
>>> >
>>> > Thanks,
>>> >
>>> > Jon.
>>>
>>>
>>>
>>> --
>>> Iris Couch
>>>
>
>
>
> --
> Iris Couch


--=20
Jon

Jonathan Williamson
Systems Architect
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