curator-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Luo Fucong <bayinam...@gmail.com>
Subject Re: Why PathChildrenCache does not have "cversion"?
Date Wed, 21 Oct 2015 04:46:49 GMT
My requirement is building a tree with only one level (root plus its first level children).
TreeCache, however, will build the entire tree with however many levels the root has.

So basically, I need a “NodePathChildrenCache” that’s NodeCache + PathChildrenCache
:)

> 在 2015年10月21日,下午12:37,Jordan Zimmerman <jordan@jordanzimmerman.com>
写道:
> 
> 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!
>>> 
>> 
> 


Mime
View raw message