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From Jordan Zimmerman <jor...@jordanzimmerman.com>
Subject Re: Why PathChildrenCache does not have "cversion"?
Date Wed, 21 Oct 2015 04:37:18 GMT
Well, that’s not what PathChildrenCache is for. You could start a NodeCache for the parent
node I guess. Or use TreeCache. But, I don’t know what the use case is so I can’t comment
in more detail.

-Jordan

> On Oct 20, 2015, at 11:34 PM, Luo Fucong <bayinamine@gmail.com> wrote:
> 
> Thanks for the reply.
> 
> Sorry for the ambiguous meaning of “path node”. By saying “path node”, I mean
the common root node of the children.
> 
> So PathChildrenCach does store the children nodes Stat, but it does not store the root
node's Stat.
> 
> For instance, I have created a PathChildrenCach cache = new PathChildrenCache(“/path/to/node”).
> I can get the Stat of “/path/to/node/child1”, but I cannot get the Stat of “/path/to/node”
directly from the cache.
> 
>> 在 2015年10月21日,下午12:18,Jordan Zimmerman <jordan@jordanzimmerman.com>
写道:
>> 
>> PathChildrenCache stores the node’s Stat object in the ChildData. So, all the data
you want is there. 
>> 
>> -JZ
>> 
>>> On Oct 20, 2015, at 11:13 PM, 罗傅聪 <bayinamine@gmail.com> wrote:
>>> 
>>> Hi all:
>>> 
>>> I recently went through the PathChildrenCache source code (in curator-recipes-2.9.0)
and found that it does not store the path node’s “cversion”, which indicating the number
of changes to the children of this znode. (Correct me if I’m wrong.)
>>> 
>>> I think the “cversion” is a very important version number which enable us
to verify that the PathChildrenCache is really catch up to the remote zookeeper znodes.
>>> 
>>> So I’m wondering that:
>>> 
>>> 1. why the PathChildrenCache does not store “cversion”, or furthermore, why
it does not store the path node’s status?
>>> 
>>> 2. are there other means I can use to verify that the PathChildrenCache is not
falling behind the remote znodes?
>>> 
>>> Thanks!
>> 
> 


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