* (executor-api) Make executor API talk GRPC
The executor's REST API was very fragile and annoying to work with, lacking even basic type safety. Migrate to use GRPC instead. GRPC is a bit of a pain with how verbose it is, but that is probably a lesser evil. This is a fairly straightforward change, but it's also large so a solid round of testing is needed...
The change set breaks out the GrpcStubPool previously residing in the QueryService, and makes it available to all clients.
ServiceId.name was also renamed to avoid the very dangerous clash with Enum.name().
The boilerplate needed for grpc was also extracted into a common gradle file for inclusion into the appropriate build.gradle-files.
This changeset adds an action for downloading a set of sample data from downloads.marginalia.nu.
It also refactors out some leaky abstractions out of FileStorageService. allocateTemporaryStorage has been renamed allocateStorage. The storage was never temporary in any scenario...
It also doesn't take a storage base, as there was always only one valid option for this input. The allocateStorage method finds the appropriate base itself.
This commit overhauls a lot of the UX for the control service, adding a new actions menu to the nodes views. It has many small tweaks to make the work flow better.
It also adds a new /uploads directory in each index node, from which sideloaded data can be selected. This is a bit of a breaking change, as this directory needs to exist in each index node.
A race condition was found where precession actors would sometimes skip a step, because when invoking ExecutorRemoteActor.getState(), it would get the last 'OK' actor state from a previous run of the actor!
To avoid this, the trigger method was changed from returning a boolean to the message ID, negative if an error occurred, to be passed to getState to select only messages that pertain to the present or future runs.
* Encyclopedia sideloader; permit providing base URL.
* Storage base shows node id in GUI
* ProcessLivenessMonitorActor restarts automatically
* Clean-up of outbox code
This turned out to be very difficult to do in small isolated steps.
* Design overhaul of the control gui using bootstrap
* Move the actors out of control-service into to a new executor-service, that can be run on multiple nodes
* Add node-affinity to message queue
