Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Threaded View
Zookeeper >> mail # user >> lost ZK events across datacenters


Copy link to this message
-
Re: lost ZK events across datacenters
can you tell us a bit more about the scenario? what was the call the
set the watch event? and what were the changes that caused the event?

thanx
ben

On Wed, Jun 1, 2011 at 3:14 PM, Jun Rao <[EMAIL PROTECTED]> wrote:
> All my clients were on different machines. 2 of them got the watcher fired
> about the same time. The third one never got the watcher triggered.
>
> Thanks,
>
> Jun
>
> On Wed, Jun 1, 2011 at 2:18 PM, Fournier, Camille F. [Tech] <
> [EMAIL PROTECTED]> wrote:
>
>> All clients are in different processes?
>> I've used zkclient and haven't seen any problems, but I haven't hammered it
>> too hard yet. I took a long look at the code and didn't see any errors but
>> there could always be something very subtle.
>>
>> -----Original Message-----
>> From: Jun Rao [mailto:[EMAIL PROTECTED]]
>> Sent: Wednesday, June 01, 2011 4:09 PM
>> To: [EMAIL PROTECTED]
>> Subject: Re: lost ZK events across datacenters
>>
>> I am using the zkclient package (
>> https://github.com/sgroschupf/zkclient.git).
>> The watcher code seems reasonable. Basically, each watcher event is first
>> added to a queue. A separate event thread dequeues each event and reads the
>> children of a path (which re-registers the watcher) and invokes the
>> registered listener.
>>
>> Anybody knows any issues in zkclient?
>>
>> Thanks,
>>
>> Jun
>>
>> On Wed, Jun 1, 2011 at 12:04 PM, Ted Dunning <[EMAIL PROTECTED]>
>> wrote:
>>
>> > This is most commonly due, in my own history of programming errors, to
>> > writing code that has a race window in it.  It is conceivable that cross
>> > data-center operation would make such a race more of a problem.
>> >
>> > Can you say a bit about your code?  Did you make sure to use standard
>> > idioms
>> > as opposed to setting the watch in a different call from reading the
>> data?
>> >
>> > On Wed, Jun 1, 2011 at 11:40 AM, Jun Rao <[EMAIL PROTECTED]> wrote:
>> >
>> > > Hi,
>> > >
>> > > I have a setup where multiple ZK clients are sitting in a different
>> > > datacenter from the ZK server. All clients registered the same child
>> > > watcher
>> > > on a path. However, when the children of the path changed, the watcher
>> on
>> > 1
>> > > of the clients didn't fire. This seems to have happened a couple of
>> times
>> > > to
>> > > me. I am using ZK 3.3.3. Has anyone used ZK in a cross datacenter setup
>> > and
>> > > seen problems like that before?
>> > >
>> > > Thanks,
>> > >
>> > > Jun
>> > >
>> >
>>
>
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB