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apache-zookeeperttl

Renew TTL of a node in Zookeeper

I am keeping some configuration on Zookeeper which a what to expire after some time if it has not being updated.

By using TTL, I can achieve that, but how do I renew the TTL? remove and add node is an option but produce inconsistent states.

Would setData(same data) or Op.check renew the TTL of the node?

Thanks in advance!

Solution

  • setData will renew the TTL of the node.
    Actually, not renew the ttl, but renew the mtime of the node. In Zookeeper, the way to check if a node should expire is to compare the return of getElapsed and configured TTL. setData will renew the mtime.

    protected long getElapsed(DataNode node) {
    return Time.currentWallTime() - node.stat.getMtime();
}