Architecture

// Least-loaded score calculation
score = active_jobs + cpu_load/100 + gpu_utilization/100

// Worker selection priority:
1. Direct dispatch to worker.<id>.jobs (if preferred_worker_id set)
2. Capability filtering (requires: kubectl, GPU, network)
3. Lowest score worker in eligible pool
4. Fallback to topic queue (job.*) if no workers available

// Overload detection:
if (active_jobs > max_parallel_jobs * 0.9) {
  reason = "pool_overloaded"
  // Scheduler waits or DLQs
}

1. Client writes input JSON to Redis at ctx:<job_id>
2. Publishes BusPacket{JobRequest} to sys.job.submit
3. Scheduler sets state PENDING
4. Scheduler calls Safety Kernel for policy evaluation
   • ALLOW → proceed to dispatch
   • DENY → state DENIED, create DLQ entry
   • REQUIRE_APPROVAL → state APPROVAL_REQUIRED, wait
   • ALLOW_WITH_CONSTRAINTS → apply constraints, proceed
   • THROTTLE → retry after backoff delay (rate limiting)
   • UNAVAILABLE → Safety Kernel unreachable, use last-known-good policy
5. Scheduler picks subject and dispatches:
   PENDING → SCHEDULED → DISPATCHED → RUNNING
6. Worker loads context, executes, writes res:<job_id>
7. Worker publishes BusPacket{JobResult} to sys.job.result
8. Scheduler updates terminal state:
   • SUCCEEDED (exit 0)
   • FAILED (worker reported failure)
   • CANCELLED (sys.job.cancel received)
   • TIMEOUT (reconciler marks stale jobs)
9. DLQ entry created for non-SUCCEEDED results

Note: JobResult also supports FAILED_RETRYABLE and
FAILED_FATAL status codes for worker-level failure
categorization.

message BusPacket {
  string trace_id = 1;          // request trace ID
  string sender_id = 2;         // component or worker ID
  google.protobuf.Timestamp created_at = 3;
  int32 protocol_version = 4;   // currently 1

  oneof payload {
    JobRequest job_request = 10;
    JobResult job_result = 11;
    Heartbeat heartbeat = 12;
    JobProgress job_progress = 13;
    JobCancel job_cancel = 14;
    SystemAlert system_alert = 15;
  }

  bytes signature = 99;         // optional, not enforced yet
}