[store] resource quota and isolation

[BohuTANG]

Summary

Because the store is multi-tenant with different levels of users requesting on it, we need to do some quota and isolation for the resource.

[drmingdrmer]

Quote:

• A centralized fast storage service for collecting user access statistics.
• An algorithm to allocate resource evenly to every store-node, with the consideration of unevenly distributed user access.
• A throttle component on every store node.
• A user-friendly response design.

Isolation:

If fuse store is only used by fuse-query, this can be done by a query node, with the information provided by store that what store-node a user is bound to.

Otherwise, store need to provide a redirect response, to inform a client to access other store node.
But for untrusted client, I am not sure if this strategy will work as expected.

[BohuTANG]

The quota(call throttle is more better) is to prevent some special users slow down the store, for example, select * from tb1.
Isolation can be thought later.

[BohuTANG]

The store is lift to compute node, closed.