Github user breed commented on a diff in the pull request:
https://github.com/apache/zookeeper/pull/584#discussion_r205959572
--- Diff: src/java/main/org/apache/zookeeper/server/DataTree.java ---
@@ -478,7 +478,10 @@ public void createNode(final String path, byte data[],
List<ACL> acl,
HashSet<String> list = ephemerals.get(ephemeralOwner);
if (list == null) {
list = new HashSet<String>();
- ephemerals.put(ephemeralOwner, list);
+ HashSet<String> _list;
--- End diff --
we need synchronization to prevent znode changes while the znode is being
snapshot to disk, but for request processing there is only a single thread that
does mutations and mutations don't happen while read requests are being
processed.
---
