couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Randall Leeds <>
Subject Re: interested in learning about replication algorithm
Date Tue, 15 Feb 2011 22:37:03 GMT
On Tue, Feb 15, 2011 at 07:30, Aaron Boxer <> wrote:
> Interesting. Thanks!
> How do version ids get generated?  How do the different nodes
> avoid version id collision; i.e. two nodes updating a document with the
> same version id?

The revision id contains both a monotonically increasing number
revision number and a hash of the document contents. The hash breaks
ties (storing the conflict, not resolving it, but deterministically
choosing a privileged version to report as the "newest").

In this manner, should two nodes perform the same update the revision
is said to exist in both places already and replication will note this
and not copy the document again.


View raw message