Hi, I have a set of resources each of which has a unique identifier. Each resource element must be locked before it is used, and unlocked afterwards.
The logic of the application is something like: lock any one element; if (none locked) then exit with error; else get resource-id from lock use resource unlock resource end Zookeeper looks like a good candidate for managing these locks, being fast and resilient, and it seems quite simple to recover from client failure. However, I cannot think of a good way to implement this sort of one-of-many locking. I could create a directory called "available" and another called "locked". Available would have one entry for each resource id ( or one entry containing a list of the resource-ids). For locking, I could loop through the available ids, attempting to create a lock for that in the locked directory. However this seems a bit clumsy and slow. Also, the locks are held for a relatively short time (1 second on average), and by time I have blundered through all the possible locks, ids that were locked at the start might be available by time I finished. Can anyone think of a more elegant and efficient way of doing this ? regards, Martin
