The PR is updating storage server and Redwood to enable encryption based on the encryption mode in DB config, which was previously controlled by a knob. High level changes are
1. Passing encryption mode in DB config to storage server
1.1 If it is a new storage server, pass the encryption mode through `InitializeStorageRequest`. the encryption mode is pass to Redwood for initialization
1.2 If it is an existing storage server, on restart the storage server will send `GetStorageServerRejoinInfoRequest` to commit proxy, and commit proxy will return the current encryption mode, which it get from DB config on its own initialization. Storage server will compare the DB config encryption mode to the local storage encryption mode, and fail if they don't match
2. Adding a new `encryptionMode()` method to `IKeyValueStore`, which return a future of local encryption mode of the KV store instance. A KV store supporting encryption would need to persist its own encryption mode, and return the mode via the API.
3. Redwood accepts encryption mode from its constructor. For a new Redwood instance, caller has to specific the encryption mode, which will be stored in Redwood per-instance file header. For existing instance, caller is supposed to not passing the encryption mode, and let Redwood find it out from its own header.
4. Refactoring in Redwood to accommodate the above changes.
The `recoveredDiskFiles` is a promise that will be fulfilled once all the local TLog and storage files have been initialized in a process. It was added previously to make a process wait on it before joining the cluster, and it was to avoid a slow recovering TLog to join the cluster to slowdown cluster recovery.
With #7510, we allow a process to join the cluster to play stateless role, while still avoid it to join the cluster as stateful role before its TLog and storage is recovered. As such, the `recoveredDiskFiles` wait is no longer needed. This PR cleanup the logic.
Previously with EaR we always enable authentication (e.g. we encrypt Redwood pages). The authentication is a form of checksum, so dedicated page checksum was not needed. This PR adds back xxhash page checksum when authentication is disabled. Also change the knob to default disable authentication.
The logic to determine the validity of a process joining a cluster now
belongs on the worker and the cluster controller. It is no longer
restricted to tlogs and storages, but instead applies to all processes
(even stateless ones).
Chaoguang Lin