[sheepdog] sheepkeeper: a new cluster manager specialized for sheepdog

[Hitoshi Mitake]

Hi,

I'm developing a new cluster manager specialized for sheepdog, named
sheepkeeper.
The source code can be found in:
https://github.com/mitake/sheepdog/tree/sheepkeeper-devel

This is still very incomplete, very buggy and very inefficient. The
degree of incompleteness is that it doesn't free() obsolete memory
area and checking return values of system calls which must be done.
In addition, it can't handle many important situation of join and
leave of nodes. And it doesn't handle almost every error.

sheepkeeper cluster manager is designed as master-slave. So it can be
SPOF. But I'm planning to let it be redundant by utilizing corosync.

If it can be improved, this can nr an alternative of the group
management part of ZooKeeper, and it doesn't depend on JVM.

If you have some opinions or feature requests for a cluster manager
designed and implemented from scratch, I'd like to hear your comments.

Thanks,
Hitoshi