Hi all, We're seeing a puzzling error. Here's the scenario:
1. We have a single thread that wakes up every two seconds (give or take) and does some work 2. As part of that work it updates a node on ZK. When it does this it first gets the Stat of the existing node and uses the version retrieved from it to update the value. 3. There are no other processes updating the node The code goes something like this: final Stat stat = zooKeeper.exists(path, false); // do some other work here to create the path if it does not exist - this code only ever gets called once zooKeeper.setData(path, value, stat.getVersion()); What we're seeing is that every so often (once every 5 minutes or so?) is that that setData() call fails with a BadVersionException. This is very unexpected because, as I mentioned previously, this thread is the sole updater of that node. One possibility I am considering is that we are using the wrong number of ZKs in our cluster - i.e 2 nodes. I am wondering if 2 is the worst number of nodes possible for ZK as there is no way to resolve a disagreement. Another possibility is that we are using an old version of ZK (3.2.2), perhaps there is a known bug with it? Though I see nothing related to this in the release logs for subsequent versions. Thoughts/suggestions? Thanks, Ishaaq
