Golang RangeDescriptor.GetReplicaDescriptor方法代碼示例

// FindRangeLease is similar to FindRangeLeaseHolder but returns a Lease proto
// without verifying if the lease is still active. Instead, it returns a time-
// stamp taken off the queried node's clock.
func (tc *TestCluster) FindRangeLease(
	rangeDesc *roachpb.RangeDescriptor, hint *ReplicationTarget,
) (_ *roachpb.Lease, now hlc.Timestamp, _ error) {
	if hint != nil {
		var ok bool
		if _, ok = rangeDesc.GetReplicaDescriptor(hint.StoreID); !ok {
			return nil, hlc.ZeroTimestamp, errors.Errorf(
				"bad hint: %+v; store doesn't have a replica of the range", hint)
		}
	} else {
		hint = &ReplicationTarget{
			NodeID:  rangeDesc.Replicas[0].NodeID,
			StoreID: rangeDesc.Replicas[0].StoreID}
	}

	// Find the server indicated by the hint and send a LeaseInfoRequest through
	// it.
	var hintServer *server.TestServer
	for _, s := range tc.Servers {
		if s.GetNode().Descriptor.NodeID == hint.NodeID {
			hintServer = s
			break
		}
	}
	if hintServer == nil {
		return nil, hlc.ZeroTimestamp, errors.Errorf("bad hint: %+v; no such node", hint)
	}
	leaseReq := roachpb.LeaseInfoRequest{
		Span: roachpb.Span{
			Key: rangeDesc.StartKey.AsRawKey(),
		},
	}
	leaseResp, pErr := client.SendWrappedWith(
		context.TODO(),
		hintServer.DB().GetSender(),
		roachpb.Header{
			// INCONSISTENT read, since we want to make sure that the node used to
			// send this is the one that processes the command, for the hint to
			// matter.
			ReadConsistency: roachpb.INCONSISTENT,
		},
		&leaseReq)
	if pErr != nil {
		return nil, hlc.ZeroTimestamp, pErr.GoError()
	}
	return leaseResp.(*roachpb.LeaseInfoResponse).Lease, hintServer.Clock().Now(), nil
}

func TestLeaseInfoRequest(t *testing.T) {
	defer leaktest.AfterTest(t)()
	tc := testcluster.StartTestCluster(t, 3,
		base.TestClusterArgs{
			ReplicationMode: base.ReplicationManual,
		})
	defer tc.Stopper().Stop()

	kvDB0 := tc.Servers[0].DB()
	kvDB1 := tc.Servers[1].DB()

	key := []byte("a")
	rangeDesc := new(roachpb.RangeDescriptor)
	var err error
	*rangeDesc, err = tc.LookupRange(key)
	if err != nil {
		t.Fatal(err)
	}

	rangeDesc, err = tc.AddReplicas(
		rangeDesc.StartKey.AsRawKey(), tc.Target(1), tc.Target(2),
	)
	if err != nil {
		t.Fatal(err)
	}
	if len(rangeDesc.Replicas) != 3 {
		t.Fatalf("expected 3 replicas, got %+v", rangeDesc.Replicas)
	}
	replicas := make([]roachpb.ReplicaDescriptor, 3)
	for i := 0; i < 3; i++ {
		var ok bool
		replicas[i], ok = rangeDesc.GetReplicaDescriptor(tc.Servers[i].GetFirstStoreID())
		if !ok {
			t.Fatalf("expected to find replica in server %d", i)
		}
	}

	// Lease should start on Server 0, since nobody told it to move.
	leaseHolderReplica := LeaseInfo(t, kvDB0, *rangeDesc, roachpb.INCONSISTENT).Lease.Replica
	if leaseHolderReplica != replicas[0] {
		t.Fatalf("lease holder should be replica %+v, but is: %+v", replicas[0], leaseHolderReplica)
	}

	// Transfer the lease to Server 1 and check that LeaseInfoRequest gets the
	// right answer.
	err = tc.TransferRangeLease(rangeDesc, tc.Target(1))
	if err != nil {
		t.Fatal(err)
	}
	// An inconsistent LeaseInfoReqeust on the old lease holder should give us the
	// right answer immediately, since the old holder has definitely applied the
	// transfer before TransferRangeLease returned.
	leaseHolderReplica = LeaseInfo(t, kvDB0, *rangeDesc, roachpb.INCONSISTENT).Lease.Replica
	if leaseHolderReplica != replicas[1] {
		t.Fatalf("lease holder should be replica %+v, but is: %+v",
			replicas[1], leaseHolderReplica)
	}

	// A read on the new lease holder does not necessarily succeed immediately,
	// since it might take a while for it to apply the transfer.
	util.SucceedsSoon(t, func() error {
		// We can't reliably do a CONSISTENT read here, even though we're reading
		// from the supposed lease holder, because this node might initially be
		// unaware of the new lease and so the request might bounce around for a
		// while (see #8816).
		leaseHolderReplica = LeaseInfo(t, kvDB1, *rangeDesc, roachpb.INCONSISTENT).Lease.Replica
		if leaseHolderReplica != replicas[1] {
			return errors.Errorf("lease holder should be replica %+v, but is: %+v",
				replicas[1], leaseHolderReplica)
		}
		return nil
	})

	// Transfer the lease to Server 2 and check that LeaseInfoRequest gets the
	// right answer.
	err = tc.TransferRangeLease(rangeDesc, tc.Target(2))
	if err != nil {
		t.Fatal(err)
	}
	leaseHolderReplica = LeaseInfo(t, kvDB1, *rangeDesc, roachpb.INCONSISTENT).Lease.Replica
	if leaseHolderReplica != replicas[2] {
		t.Fatalf("lease holder should be replica %+v, but is: %+v", replicas[2], leaseHolderReplica)
	}

	// TODO(andrei): test the side-effect of LeaseInfoRequest when there's no
	// active lease - the node getting the request is supposed to acquire the
	// lease. This requires a way to expire leases; the TestCluster probably needs
	// to use a mock clock.
}