Quantcast

Ephemeral deletion order

classic Classic list List threaded Threaded
2 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Ephemeral deletion order

lgeretti
I noticed that if a client A creates several ephemeral znodes (either sequential or not) under a common parent, and another client B has set watches for all of them, when A disconnects I receive a seemingly arbitrary (but constant for the same set of znodes) WatchEvent sequence. The sequence is neither the same as that returned when listing the children, nor the sequence of creation.
Can someone confirm me that the order of removal of ephemeral znodes is practically undefined? (..at least in a user-sensible way; I imagine that the order is driven by hashes in the persistence layer).

Thanks!
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Ephemeral deletion order

Camille Fournier
We associate ephemerals to the session id via a HashSet, so the
watches will be triggered in the order items are returned from the
HashSet, which is practically, undefined.

C

On Mon, Mar 19, 2012 at 3:25 AM, lgeretti <[hidden email]> wrote:

> I noticed that if a client A creates several ephemeral znodes (either
> sequential or not) under a common parent, and another client B has set
> watches for all of them, when A disconnects I receive a seemingly arbitrary
> (but constant for the same set of znodes) WatchEvent sequence. The sequence
> is neither the same as that returned when listing the children, nor the
> sequence of creation.
> Can someone confirm me that the order of removal of ephemeral znodes is
> practically undefined? (..at least in a user-sensible way; I imagine that
> the order is driven by hashes in the persistence layer).
>
> Thanks!
>
> --
> View this message in context: http://zookeeper-user.578899.n2.nabble.com/Ephemeral-deletion-order-tp7384823p7384823.html
> Sent from the zookeeper-user mailing list archive at Nabble.com.
Loading...