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From Benoit Chesneau <bchesn...@gmail.com>
Subject Re: [jira] [Commented] (COUCHDB-1259) Replication ID is not stable if local server has a dynamic port number
Date Mon, 05 Nov 2012 05:01:46 GMT
Ok, I will do it again. This isn't a bug but a question of what do you expect.

I think it is expected in some cases that the replication won't
restart if the address change. Or it should be a application design
not something by default in couch.

On Mon, Nov 5, 2012 at 5:48 AM, Dale Harvey <dale@arandomurl.com> wrote:
> Benoit
>
> This problem has nothing to do with any application, its a bug in CouchDB
> with a simple fix
>
>
> On 4 November 2012 20:43, Benoit Chesneau (JIRA) <jira@apache.org> wrote:
>
>>
>>     [
>> https://issues.apache.org/jira/browse/COUCHDB-1259?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13490449#comment-13490449]
>>
>> Benoit Chesneau commented on COUCHDB-1259:
>> ------------------------------------------
>>
>> Hello.... are you understanding that this isn't only about your
>> application? Some may have different uses. And different routing policy.
>> And this is not the role of couchdb to fix them.
>>
>> > Replication ID is not stable if local server has a dynamic port number
>> > ----------------------------------------------------------------------
>> >
>> >                 Key: COUCHDB-1259
>> >                 URL: https://issues.apache.org/jira/browse/COUCHDB-1259
>> >             Project: CouchDB
>> >          Issue Type: Bug
>> >          Components: Replication
>> >    Affects Versions: 1.1
>> >            Reporter: Jens Alfke
>> >            Assignee: Robert Newson
>> >            Priority: Blocker
>> >             Fix For: 1.3
>> >
>> >         Attachments: couchdb-1259.patch, couchdb-1259.patch
>> >
>> >
>> > I noticed that when Couchbase Mobile running on iOS replicates to/from a
>> remote server (on iriscouch in this case), the replication has to fetch the
>> full _changes feed every time it starts. Filipe helped me track down the
>> problem -- the replication ID is coming out different every time. The
>> reason for this is that the local port number, which is one of the inputs
>> to the hash that generates the replication ID, is randomly assigned by the
>> OS. (I.e. it uses a port number of 0 when opening its listener socket.)
>> This is because there could be multiple apps using Couchbase Mobile running
>> on the same device and we can't have their ports colliding.
>> > The underlying problem is that CouchDB is attempting to generate a
>> unique ID for a particular pair of {source, destination} databases, but
>> it's basing it on attributes that aren't fundamental to the database and
>> can change, like the hostname or port number.
>> > One solution, proposed by Filipe and me, is to assign each database (or
>> each server?) a random UUID when it's created, and use that to generate
>> replication IDs.
>> > Another solution, proposed by Damien, is to have CouchDB let the client
>> work out the replication ID on its own, and set it as a property in the
>> replication document (or the JSON body of a _replicate request.) This is
>> even more flexible and will handle tricky scenarios like full P2P
>> replication where there may be no low-level way to uniquely identify the
>> remote database being synced with.
>>
>> --
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>>

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