public void Test_Backup_Found_Primary()
{
StateChanged<InstanceState> stateChanged = null;
var observer = new MockStateObserver(s => stateChanged = s, Assert.IsNull);
InstanceState localState;
ClusterStateMachine machine = CreateClusterStateMachine(observer, NodeRole.Backup, out localState);
var remoteState = new NodeState { Role = NodeRole.Primary, Status = NodeStatus.Connecting };
machine.RaiseEvent(localState, machine.PartnerStatusReceived, remoteState);
Assert.AreEqual("Connecting", stateChanged.Previous.Name);
Assert.AreEqual("Passive", stateChanged.Current.Name);
}
public void Test_LostPartner_During_Any_Should_LogException()
{
StateChanged<InstanceState> stateChanged = null;
var observer = new MockStateObserver(s => stateChanged = s, Assert.IsNull);
InstanceState localState;
ClusterException cex = null;
ClusterStateMachine machine = CreateClusterStateMachine(observer, NodeRole.Primary, out localState,
ex => cex = ex);
var remoteState = new NodeState { Role = NodeRole.Backup, Status = NodeStatus.Passive };
machine.RaiseEvent(localState, machine.PartnerStatusReceived, remoteState);
machine.RaiseEvent(localState, machine.LostPartner, localState);
Assert.AreEqual(ClusterFailureReason.LostPartner, cex.Reason);
Assert.AreEqual("Connecting", stateChanged.Previous.Name);
Assert.AreEqual("Active", stateChanged.Current.Name);
}
public void Test_InvalidTopology()
{
StateChanged<InstanceState> stateChanged = null;
var observer = new MockStateObserver(s => stateChanged = s, Assert.IsNull);
InstanceState localState;
ClusterException cex = null;
ClusterStateMachine machine = CreateClusterStateMachine(observer, NodeRole.Primary, out localState,
ex => cex = ex);
var remoteState = new NodeState { Role = NodeRole.Primary, Status = NodeStatus.Connecting };
machine.RaiseEvent(localState, machine.PartnerStatusReceived, remoteState);
Assert.AreEqual(ClusterFailureReason.InvalidTopology, cex.Reason);
Assert.AreEqual("Stopped", stateChanged.Previous.Name);
Assert.AreEqual("Final", stateChanged.Current.Name);
machine = CreateClusterStateMachine(observer, NodeRole.Backup, out localState, ex => cex = ex);
remoteState = new NodeState { Role = NodeRole.Backup, Status = NodeStatus.Connecting };
machine.RaiseEvent(localState, machine.PartnerStatusReceived, remoteState);
Assert.AreEqual(ClusterFailureReason.InvalidTopology, cex.Reason);
Assert.AreEqual("Stopped", stateChanged.Previous.Name);
Assert.AreEqual("Final", stateChanged.Current.Name);
}
private static ClusterStateMachine CreateClusterStateMachine(MockStateObserver observer, NodeRole role,
out InstanceState localState, Action<ClusterException> clusterExceptionAction = null, bool becomeActiveWhenPrimaryOnInitialConnectionTimeout = false)
{
var machine = new ClusterStateMachine(clusterExceptionAction ?? Assert.IsNull, s => true, becomeActiveWhenPrimaryOnInitialConnectionTimeout);
machine.StateChanged.Subscribe(observer);
localState = new InstanceState { Role = role };
machine.RaiseEvent(localState, machine.Start);
return machine;
}
public void Test_Start_When_Initial()
{
StateChanged<InstanceState> stateChanged = null;
var observer = new MockStateObserver(s => stateChanged = s, Assert.IsNull);
InstanceState localState;
ClusterStateMachine machine = CreateClusterStateMachine(observer, NodeRole.Primary, out localState);
Assert.AreEqual("Initial", stateChanged.Previous.Name);
Assert.AreEqual("Connecting", stateChanged.Current.Name);
}
public void Test_SplitBrain_Backup()
{
StateChanged<InstanceState> stateChanged = null;
var observer = new MockStateObserver(s => stateChanged = s, Assert.IsNull);
InstanceState localState;
ClusterException cex = null;
ClusterStateMachine machine = CreateClusterStateMachine(observer, NodeRole.Backup, out localState,
ex => cex = ex);
var newState = new InstanceState
{
CurrentState = machine.Active,
Role = NodeRole.Backup,
Status = NodeStatus.Active
};
machine.TransitionToState(newState, machine.Active);
var remoteState = new NodeState { Role = NodeRole.Primary, Status = NodeStatus.Active };
machine.RaiseEvent(newState, machine.PartnerStatusReceived, remoteState);
Assert.AreEqual(ClusterFailureReason.SplitBrain, cex.Reason);
Assert.AreEqual("Stopped", stateChanged.Previous.Name);
Assert.AreEqual("Final", stateChanged.Current.Name);
}
public void Test_Primary_BecomeStandAlone_WhenInitialConnectToBackup_Fails()
{
StateChanged<InstanceState> stateChanged = null;
var observer = new MockStateObserver(s => stateChanged = s, Assert.IsNull);
InstanceState localState;
ClusterStateMachine machine = CreateClusterStateMachine(observer, NodeRole.Primary, out localState, becomeActiveWhenPrimaryOnInitialConnectionTimeout: true);
machine.RaiseEvent(localState, machine.LostPartner, localState);
Assert.AreEqual("Connecting", stateChanged.Previous.Name);
Assert.AreEqual("Active", stateChanged.Current.Name);
}
private static ClusterStateMachine CreateClusterStateMachine(MockStateObserver observer, NodeRole role,
out InstanceState localState, Action<ClusterException> clusterExceptionAction = null)
{
var machine = new ClusterStateMachine(clusterExceptionAction ?? Assert.IsNull, s => true);
machine.StateChanged.Subscribe(observer);
localState = new InstanceState {Role = role};
machine.RaiseEvent(localState, machine.Start);
return machine;
}