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From Vitalii Tymchyshyn <tiv...@gmail.com>
Subject Re: Get sequence number without node creation
Date Fri, 18 Nov 2011 12:41:47 GMT
17.11.11 18:54, Sean Bridges написав(ла):
> Can you do,
>
> Stat stat = zk.setData(somePath, new byte[] {});
> stat.getVersion();
>
> setData(...) will update the version number of the node.

Is it guarantied that two calls won't receive same stat? (E.g. some kind 
of merging of two setData).

> This is how we use zookeeper for sequence number generation.
>
> Sean
>
> On Thu, Nov 17, 2011 at 1:59 AM, Vitalii Tymchyshyn<tivv00@gmail.com>  wrote:
>> Hello.
>>
>> I have a feature request I'd like to discuss: How about a call that will
>> give next sequential node number without node creation. Main reason is that
>> in many cases this would allow retries without leak on reconnect, e.g.:
>> Now:
>> 1) create(SEQUENTIAL) - disconnect - retry - and you've just leaked a node
>> Can be
>> 2) incrementCounter() - create(name). And you can make a retry in any place.
>> The worst thing that can occur is that you will have a hole in your
>> numbering
>>
>> Another cases this can help are simple counters (no need to create nodes at
>> all) or simply different sequential nodes naming schema.
>>
>> Best regards, Vitalii Tymchyshyn
>>


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