In order to minimize this change while keeping a simple version of the
behavior, we set `lastOk` to the current time less the intial server
connection timeout. If the client starts and never contacts the
server, it will stop all configured tasks after the initial server
connection grace period, on the assumption that we've been out of
touch longer than any configured `stop_after_client_disconnect`.
The more complex state behavior might be justified later, but we
should learn about failure modes first.
- track lastHeartbeat, the client local time of the last successful
heartbeat round trip
- track allocations with `stop_after_client_disconnect` configured
- trigger allocation destroy (which handles cleanup)
- restore heartbeat/killable allocs tracking when allocs are recovered from disk
- on client restart, stop those allocs after a grace period if the
servers are still partioned
In order to correctly fingerprint dynamic plugins on client restarts,
we need to persist a handle to the plugin (that is, connection info)
to the client state store.
The dynamic registry will sync automatically to the client state
whenever it receives a register/deregister call.
The driver manager is modeled after the device manager and is started by the client.
It's responsible for handling driver lifecycle and reattachment state, as well as
processing the incomming fingerprint and task events from each driver. The mananger
exposes a method for registering event handlers for task events that is used by the
task runner to update the server when a task has been updated with an event.
Since driver fingerprinting has been implemented by the driver manager, it is no
longer needed in the fingerprint mananger and has been removed.
Introduce a device manager that manages the lifecycle of device plugins
on the client. It fingerprints, collects stats, and forwards Reserve
requests to the correct plugin. The manager, also handles device plugins
failing and validates their output.
* Migrated all of the old leader task tests and got them passing
* Refactor and consolidate task killing code in AR to always kill leader
tasks first
* Fixed lots of issues with state restoring
* Fixed deadlock in AR.Destroy if AR.Run had never been called
* Added a new in memory statedb for testing
* Stopping an alloc is implemented via Updates but update hooks are
*not* run.
* Destroying an alloc is a best effort cleanup.
* AllocRunner destroy hooks implemented.
* Disk migration and blocking on a previous allocation exiting moved to
its own package to avoid cycles. Now only depends on alloc broadcaster
instead of also using a waitch.
* AllocBroadcaster now only drops stale allocations and always keeps the
latest version.
* Made AllocDir safe for concurrent use
Lots of internal contexts that are currently unused. Unsure if they
should be used or removed.
