In ZooKeeper, is there a way to write a hierarchy atomically without implementing distributed locks yourself?

Question

let's say I want to write out this tree to zookeeper

.            a
.           / \
.          b   c
.         / \
.        d   e

some other client could come along and delete node b right after I create it but before I'm able to write node 'd' or 'e'.

Is there a way I can write this hierarchy atomically, or possibly lock a certain path?

Answer 1

You can use the new multi() API

It completes all the operations or aborts them all.

Answer 2

You can coordinate different clients by either electing a leader or maintaining locks You can read a nice description on Zookeeper's recipes on the Netflix curator docs (which is also a nice library to use if you want to do anything with zookeeper)