Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Zookeeper, mail # dev - order of async requests to zookeeper


Copy link to this message
-
Re: order of async requests to zookeeper
Ted Yu 2011-12-23, 18:43
The requests come from same zhandle.

Cheers

On Thu, Dec 22, 2011 at 6:09 PM, Ted Yu <[EMAIL PROTECTED]> wrote:

> Hi,
> The following originated from discussion on a feature in HBase which
> relies on zookeeper for coordination.
>
> A task is removed from the tasks map. An async ZK request is pending to
> remove the task's zk node.
>
>  Another request arrives for this to-be-deleted task. A new in-memory
> task structure is created. A ZK request is scheduled to create the same
> task node.
>
>  Problem will only occur if create-node executes before delete-node in
> ZK. (If create-node returns NODEEXISTS then we treat that as success).
>
> Does ZK re-order async requests?
>
> Thanks
>