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From Ted Dunning <ted.dunn...@gmail.com>
Subject redundant watches
Date Wed, 18 Jan 2012 23:50:46 GMT
I just had a question from an engineer regarding watches.  I realized in
answering that I am not 100% sure that my answer is correct and would like
some confirmation.

The scenario is when redundant watches are set on a znode.  The questions

a) is there any adverse impact to redundant watches in which the same
Watcher object is set as watcher for the same operations on the same node.
 (proposed answer: I don't think so.  I think all watches will be triggered
in sequence just like non-redundant watches).

b) is there any way to determine whether a watch is already set or a list
of all watches already set?  (proposed answer:  I don't think so.  There
certainly isn't any obvious way in the API to do this)

c) is there any way to cancel a watch.  (proposed answer: I don't think so.
 There has been recent action on this, but nothing final yet)

d) is there a way to create a watch such that there is exactly one watch
for the session on a particular znode?  (proposed answer: I don't see any

Can somebody confirm or deny these answers?

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