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Posted to user@couchdb.apache.org by Mark Hahn <ma...@hahnca.com> on 2011/12/16 21:26:16 UTC
reduce error algorithm?
What is the algorithm for determining whether a reduce is happening fast
enough? I went to a lot of trouble to develop a map/reduce that
intermittently gives this error. I don't like programming where I can't
predict whether something will work or not. It reminds me of developing an
app for ios and then being told it can't go in the app store.
Re: reduce error algorithm?
Posted by Dave Cottlehuber <da...@muse.net.nz>.
On 16 December 2011 21:26, Mark Hahn <ma...@hahnca.com> wrote:
> What is the algorithm for determining whether a reduce is happening fast
> enough? I went to a lot of trouble to develop a map/reduce that
> intermittently gives this error. I don't like programming where I can't
> predict whether something will work or not. It reminds me of developing an
> app for ios and then being told it can't go in the app store.
It doesn't answer the question but may solve your issue. You can tweak
reduce heuristics in local.ini, re-use the content from
https://github.com/apache/couchdb/blob/master/etc/couchdb/default.ini.tpl.in#L73-78
I've not seen many questions on this so hoping one of the committers chimes in
with pithy insight.
A+D
Re: reduce error algorithm?
Posted by "Jim R. Wilson" <wi...@gmail.com>.
To debug, you could wrap the contents of your reducer in a try/catch, then
have it emit an error as output. Your re-reducer would then ignore errors
(re-emit them).
The error object you output could have the original arguments as one if its
properties, so you could inspect and reproduce the issue.
I haven't had this particular problem, these are just some ideas off the
top of my head. Good luck!
-- Jim R. Wilson (seven databases in seven weeks)
On Fri, Dec 16, 2011 at 3:26 PM, Mark Hahn <ma...@hahnca.com> wrote:
> What is the algorithm for determining whether a reduce is happening fast
> enough? I went to a lot of trouble to develop a map/reduce that
> intermittently gives this error. I don't like programming where I can't
> predict whether something will work or not. It reminds me of developing an
> app for ios and then being told it can't go in the app store.
>
Re: reduce error algorithm?
Posted by Mark Hahn <ma...@hahnca.com>.
Thanks to both of you.
On Fri, Dec 16, 2011 at 12:57 PM, Zachary Zolton
<za...@gmail.com>wrote:
> Here's an old thread on the issue:
>
> http://comments.gmane.org/gmane.comp.db.couchdb.user/3739
>
> On Fri, Dec 16, 2011 at 2:26 PM, Mark Hahn <ma...@hahnca.com> wrote:
> > What is the algorithm for determining whether a reduce is happening fast
> > enough? I went to a lot of trouble to develop a map/reduce that
> > intermittently gives this error. I don't like programming where I can't
> > predict whether something will work or not. It reminds me of developing
> an
> > app for ios and then being told it can't go in the app store.
>
Re: reduce error algorithm?
Posted by Zachary Zolton <za...@gmail.com>.
Here's an old thread on the issue:
http://comments.gmane.org/gmane.comp.db.couchdb.user/3739
On Fri, Dec 16, 2011 at 2:26 PM, Mark Hahn <ma...@hahnca.com> wrote:
> What is the algorithm for determining whether a reduce is happening fast
> enough? I went to a lot of trouble to develop a map/reduce that
> intermittently gives this error. I don't like programming where I can't
> predict whether something will work or not. It reminds me of developing an
> app for ios and then being told it can't go in the app store.