couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jason Smith <...@apache.org>
Subject Re: Replication vs. Compaction
Date Fri, 31 Jan 2014 20:11:29 GMT
On Sat, Feb 1, 2014 at 2:27 AM, Boaz Citrin <bcitrin@gmail.com> wrote:

> @Jason - the purpose is that compaction will not catch up with heavy
> write rate and will affect performance.
>

If compaction will not catch up with your writes, then you do not have
sufficient hardware resources. You are operating in a very high-risk
environment. Replication in lieu of compaction is papering over a deeper
problem. You may have a strong threat of consuming all of your filesystem
space or i/o bandwidth is high. Consider upgrading to faster SAS or SSD
storage.

Of course, you know your situation better than I do. Maybe you have good
reasons for your specific situation. But the above paragraph should be a
pretty useful rule of thumb.

So I replicate/copy to a side database, compact it, then replicate the
> new changes from the original and switchover.
>

I do not understand. If couch can compact the side database, then it can
compact the primary database. The compaction code is doing everything you
describe, except automatically, without external direction, and with plenty
of debugging over the years.

I encourage you to tested and confirm whether compaction can not catch up
with your heavy write rate? Of course if you have working code in place
now, then hey CouchDB is relaxed. Keep using what works! :)

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message