Hi, I am currently working on ZOOKEEPER-1383. One of the main feature introduced in this change is to allow ZooKeeper to enforce hard limit (e.g. Txn per sec) per folder .
With hard limit, we need to introduce a new exception/error code (QuotaExceeded) for ZooKeeper operations that modify the DataTree. If a client get this error, it means that the particular operation is definitely failed. >From our internal discussion, this may make it harder for a user to write an >application. The thought is that this can possibly introduce a hole in >sequence of operations that the client application performs, since some >operation may success but some may be not. One of the idea is to also >trigger session expire (or at least trigger disconnect) on the server-side in >addition to QuotaExceed error. This will cause all subsequent operations from >that client to fail and allow the application to use existing error handling >logic to recover from QuotaExceed. Typically, the application that exceeded >the quota is already doing something wrong from administrator's perspective, >but we also want to fail gracefully and able to recover when the problem is >fixed or quota is increased. Let me know if you have any suggestion. -- Thawan Kooburat
