scheduler: make version checks specific to region

Disconnected clients handling is specific to a single region, so we don't want
to enforce that the version check across all of serf, just members in the same
region.

nomad/worker.go

@@ -581,11 +581,11 @@ func (w *Worker) invokeScheduler(snap *state.StateSnapshot, eval *structs.Evalua
 	return nil
 }
 
-// ServersMeetMinimumVersion allows implementations of the Scheduler interface in
+// RegionServersMeetMinimumVersion allows implementations of the Scheduler interface in
 // other packages to perform server version checks without direct references to
 // the Nomad server.
-func (w *Worker) ServersMeetMinimumVersion(minVersion *version.Version, checkFailedServers bool) bool {
-	return ServersMeetMinimumVersion(w.srv.Members(), minVersion, checkFailedServers)
+func (w *Worker) RegionServersMeetMinimumVersion(minVersion *version.Version, checkFailedServers bool) bool {
+	return RegionServersMeetMinimumVersion(w.srv.Members(), w.srv.Region(), minVersion, checkFailedServers)
 }
 
 // SubmitPlan is used to submit a plan for consideration. This allows

scheduler/generic_sched.go

@@ -378,7 +378,7 @@ func (s *GenericScheduler) computeJobAllocs() error {
 	reconciler := NewAllocReconciler(s.logger,
 		genericAllocUpdateFn(s.ctx, s.stack, s.eval.ID),
 		s.batch, s.eval.JobID, s.job, s.deployment, allocs, tainted, s.eval.ID,
-		s.eval.Priority, s.planner.ServersMeetMinimumVersion(minVersionMaxClientDisconnect, true))
+		s.eval.Priority, s.planner.RegionServersMeetMinimumVersion(minVersionMaxClientDisconnect, true))
 
 	results := reconciler.Compute()
 	s.logger.Debug("reconciled current state with desired state", "results", log.Fmt("%#v", results))

scheduler/scheduler.go

@@ -134,8 +134,9 @@ type Planner interface {
 	// that on leader changes, the evaluation will be reblocked properly.
 	ReblockEval(*structs.Evaluation) error
 
-	// ServersMeetMinimumVersion returns whether the Nomad servers are at least on the
-	// given Nomad version. The checkFailedServers parameter specifies whether version
-	// for the failed servers should be verified.
-	ServersMeetMinimumVersion(minVersion *version.Version, checkFailedServers bool) bool
+	// RegionServersMeetMinimumVersion returns whether the Nomad servers in the
+	// worker's region are at least on the given Nomad version. The
+	// checkFailedServers parameter specifies whether version for the failed
+	// servers should be verified.
+	RegionServersMeetMinimumVersion(minVersion *version.Version, checkFailedServers bool) bool
 }

scheduler/scheduler_system.go

@@ -230,7 +230,7 @@ func (s *SystemScheduler) computeJobAllocs() error {
 
 	// Diff the required and existing allocations
 	diff := diffSystemAllocs(s.job, s.nodes, s.notReadyNodes, tainted, live, term,
-		s.planner.ServersMeetMinimumVersion(minVersionMaxClientDisconnect, true))
+		s.planner.RegionServersMeetMinimumVersion(minVersionMaxClientDisconnect, true))
 
 	s.logger.Debug("reconciled current state with desired state",
 		"place", len(diff.place), "update", len(diff.update),

scheduler/testing.go

@@ -20,7 +20,7 @@ type RejectPlan struct {
 	Harness *Harness
 }
 
-func (r *RejectPlan) ServersMeetMinimumVersion(minVersion *version.Version, checkFailedServers bool) bool {
+func (r *RejectPlan) RegionServersMeetMinimumVersion(minVersion *version.Version, checkFailedServers bool) bool {
 	return r.Harness.serversMeetMinimumVersion
 }
 
@@ -250,7 +250,7 @@ func (h *Harness) ReblockEval(eval *structs.Evaluation) error {
 	return nil
 }
 
-func (h *Harness) ServersMeetMinimumVersion(_ *version.Version, _ bool) bool {
+func (h *Harness) RegionServersMeetMinimumVersion(_ *version.Version, _ bool) bool {
 	return h.serversMeetMinimumVersion
 }