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Zookeeper, mail # user - Get sequence number without node creation


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Re: Get sequence number without node creation
nileader 2011-11-20, 10:13
No。any time,two return result will be by two update request.

2011/11/18 Vitalii Tymchyshyn <[EMAIL PROTECTED]>

> 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<[EMAIL PROTECTED]>
>>  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
>>>
>>>
>