protected virtual void Dispose(bool disposing)
{
if (_state.TryChange(State.Disposed))
{
#pragma warning disable CS0618 // Type or member is obsolete
var connectionModeSwitch = _description.ConnectionModeSwitch;
var connectionMode = connectionModeSwitch == ConnectionModeSwitch.UseConnectionMode ? _description.ConnectionMode : default;
var directConnection = connectionModeSwitch == ConnectionModeSwitch.UseDirectConnection ? _description.DirectConnection : default;
var newClusterDescription = new ClusterDescription(
_clusterId,
connectionMode,
connectionModeSwitch,
directConnection,
dnsMonitorException: null,
ClusterType.Unknown,
Enumerable.Empty <ServerDescription>());
#pragma warning restore CS0618 // Type or member is obsolete
UpdateClusterDescription(newClusterDescription);
_rapidHeartbeatTimer.Dispose();
}
}
private async Task WaitForDescriptionChangedAsync(IServerSelector selector, ClusterDescription description, Task descriptionChangedTask, TimeSpan timeout, CancellationToken cancellationToken)
{
var cancellationTaskCompletionSource = new TaskCompletionSource <bool>();
using (cancellationToken.Register(() => cancellationTaskCompletionSource.TrySetCanceled()))
using (var timeoutCancellationTokenSource = new CancellationTokenSource())
{
var timeoutTask = Task.Delay(timeout, timeoutCancellationTokenSource.Token);
var completedTask = await Task.WhenAny(descriptionChangedTask, timeoutTask, cancellationTaskCompletionSource.Task).ConfigureAwait(false);
if (completedTask == timeoutTask)
{
ThrowTimeoutException(selector, description);
}
timeoutCancellationTokenSource.Cancel();
if (completedTask == cancellationTaskCompletionSource.Task)
{
cancellationToken.ThrowIfCancellationRequested();
}
await descriptionChangedTask.ConfigureAwait(false); // propagate exceptions
}
}
public WaitForDescriptionChangedHelper(Cluster cluster, IServerSelector selector, ClusterDescription description, Task descriptionChangedTask, TimeSpan timeout, CancellationToken cancellationToken)
{
_cluster = cluster;
_description = description;
_selector = selector;
_descriptionChangedTask = descriptionChangedTask;
_cancellationToken = cancellationToken;
_cancellationTaskCompletionSource = new TaskCompletionSource <bool>();
_cancellationTokenRegistration = cancellationToken.Register(() => _cancellationTaskCompletionSource.TrySetCanceled());
_timeoutCancellationTokenSource = new CancellationTokenSource();
_timeoutTask = Task.Delay(timeout, _timeoutCancellationTokenSource.Token);
}
private void ThrowTimeoutException(IServerSelector selector, ClusterDescription description)
{
var message = BuildTimeoutExceptionMessage(_settings.ServerSelectionTimeout, selector, description);
throw new TimeoutException(message);
}
private string BuildTimeoutExceptionMessage(TimeSpan timeout, IServerSelector selector, ClusterDescription clusterDescription)
{
var ms = (int)Math.Round(timeout.TotalMilliseconds);
return(string.Format(
"A timeout occured after {0}ms selecting a server using {1}. Client view of cluster state is {2}.",
ms.ToString(),
selector.ToString(),
clusterDescription.ToString()));
}
// constructors
/// <summary>
/// Initializes a new instance of the <see cref="ClusterDescriptionChangedEventArgs"/> class.
/// </summary>
/// <param name="oldClusterDescription">The old cluster description.</param>
/// <param name="newClusterDescription">The new cluster description.</param>
public ClusterDescriptionChangedEventArgs(ClusterDescription oldClusterDescription, ClusterDescription newClusterDescription)
{
_oldClusterDescription = Ensure.IsNotNull(oldClusterDescription, "oldClusterDescription");
_newClusterDescription = Ensure.IsNotNull(newClusterDescription, "newClusterDescription");
}
public async Task <IServer> SelectServerAsync(IServerSelector selector, CancellationToken cancellationToken)
{
ThrowIfDisposedOrNotOpen();
Ensure.IsNotNull(selector, "selector");
var timeoutAt = DateTime.UtcNow + _settings.ServerSelectionTimeout;
var serverSelectionWaitQueueEntered = false;
if (_settings.PreServerSelector != null || _settings.PostServerSelector != null)
{
var allSelectors = new List <IServerSelector>();
if (_settings.PreServerSelector != null)
{
allSelectors.Add(_settings.PreServerSelector);
}
allSelectors.Add(selector);
if (_settings.PostServerSelector != null)
{
allSelectors.Add(_settings.PostServerSelector);
}
selector = new CompositeServerSelector(allSelectors);
}
ClusterDescription description = null;
try
{
var stopwatch = Stopwatch.StartNew();
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
Task descriptionChangedTask;
lock (_descriptionLock)
{
descriptionChangedTask = _descriptionChangedTaskCompletionSource.Task;
description = _description;
}
if (!serverSelectionWaitQueueEntered && _selectingServerEventHandler != null)
{
// this is our first time through...
_selectingServerEventHandler(new ClusterSelectingServerEvent(
description,
selector));
}
ThrowIfIncompatible(description);
var connectedServers = description.Servers.Where(s => s.State == ServerState.Connected);
var selectedServers = selector.SelectServers(description, connectedServers).ToList();
while (selectedServers.Count > 0)
{
var server = selectedServers.Count == 1 ?
selectedServers[0] :
__randomServerSelector.SelectServers(description, selectedServers).Single();
IClusterableServer selectedServer;
if (TryGetServer(server.EndPoint, out selectedServer))
{
stopwatch.Stop();
if (_selectedServerEventHandler != null)
{
_selectedServerEventHandler(new ClusterSelectedServerEvent(
description,
selector,
server,
stopwatch.Elapsed));
}
return(selectedServer);
}
selectedServers.Remove(server);
}
if (!serverSelectionWaitQueueEntered)
{
EnterServerSelectionWaitQueue();
serverSelectionWaitQueueEntered = true;
}
var timeoutRemaining = timeoutAt - DateTime.UtcNow;
if (timeoutRemaining <= TimeSpan.Zero)
{
ThrowTimeoutException(selector, description);
}
await WaitForDescriptionChangedAsync(selector, description, descriptionChangedTask, timeoutRemaining, cancellationToken).ConfigureAwait(false);
}
}
catch (Exception ex)
{
if (_selectingServerFailedEventHandler != null)
{
_selectingServerFailedEventHandler(new ClusterSelectingServerFailedEvent(
description,
selector,
ex));
}
throw;
}
finally
{
if (serverSelectionWaitQueueEntered)
{
ExitServerSelectionWaitQueue();
}
}
}
private ClusterDescription ProcessReplicaSetChange(ClusterDescription clusterDescription, ServerDescriptionChangedEventArgs args, List <IClusterableServer> newServers)
{
if (!args.NewServerDescription.Type.IsReplicaSetMember())
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, string.Format("Server is a {0}, not a replica set member.", args.NewServerDescription.Type)));
}
if (args.NewServerDescription.Type == ServerType.ReplicaSetGhost)
{
return(clusterDescription.WithServerDescription(args.NewServerDescription));
}
if (_replicaSetName == null)
{
_replicaSetName = args.NewServerDescription.ReplicaSetConfig.Name;
}
if (_replicaSetName != args.NewServerDescription.ReplicaSetConfig.Name)
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, string.Format("Server was a member of the '{0}' replica set, but should be '{1}'.", args.NewServerDescription.ReplicaSetConfig.Name, _replicaSetName)));
}
clusterDescription = clusterDescription.WithServerDescription(args.NewServerDescription);
clusterDescription = EnsureServers(clusterDescription, args.NewServerDescription, newServers);
if (args.NewServerDescription.CanonicalEndPoint != null &&
!EndPointHelper.Equals(args.NewServerDescription.CanonicalEndPoint, args.NewServerDescription.EndPoint))
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, "CanonicalEndPoint is different than seed list EndPoint."));
}
if (args.NewServerDescription.Type == ServerType.ReplicaSetPrimary)
{
if (args.NewServerDescription.ReplicaSetConfig.Version != null)
{
bool isCurrentPrimaryStale = true;
if (_maxElectionInfo != null)
{
isCurrentPrimaryStale = _maxElectionInfo.IsStale(args.NewServerDescription.ReplicaSetConfig.Version.Value, args.NewServerDescription.ElectionId);
var isReportedPrimaryStale = _maxElectionInfo.IsFresher(
args.NewServerDescription.ReplicaSetConfig.Version.Value,
args.NewServerDescription.ElectionId);
if (isReportedPrimaryStale && args.NewServerDescription.ElectionId != null)
{
// we only invalidate the "newly" reported stale primary if electionId was used.
lock (_serversLock)
{
var server = _servers.SingleOrDefault(x => EndPointHelper.Equals(args.NewServerDescription.EndPoint, x.EndPoint));
server.Invalidate();
_sdamInformationEventHandler?.Invoke(new SdamInformationEvent(() =>
string.Format(
@"Invalidating server: Setting ServerType to ""Unknown"" for {0} because it " +
@"claimed to be the replica set primary for replica set ""{1}"" but sent a " +
@"(setVersion, electionId) tuple of ({2}, {3}) that was less than than the " +
@"largest tuple seen, (maxSetVersion, maxElectionId), of ({4}, {5}).",
args.NewServerDescription.EndPoint,
args.NewServerDescription.ReplicaSetConfig.Name,
args.NewServerDescription.ReplicaSetConfig.Version,
args.NewServerDescription.ElectionId,
_maxElectionInfo.SetVersion,
_maxElectionInfo.ElectionId)));
return(clusterDescription.WithServerDescription(
new ServerDescription(server.ServerId, server.EndPoint)));
}
}
}
if (isCurrentPrimaryStale)
{
if (_maxElectionInfo == null)
{
_sdamInformationEventHandler?.Invoke(new SdamInformationEvent(() =>
string.Format(
@"Initializing (maxSetVersion, maxElectionId): Saving tuple " +
@"(setVersion, electionId) of ({0}, {1}) as (maxSetVersion, maxElectionId) for " +
@"replica set ""{2}"" because replica set primary {3} sent ({0}, {1}), the first " +
@"(setVersion, electionId) tuple ever seen for replica set ""{4}"".",
args.NewServerDescription.ReplicaSetConfig.Version,
args.NewServerDescription.ElectionId,
args.NewServerDescription.ReplicaSetConfig.Name,
args.NewServerDescription.EndPoint,
args.NewServerDescription.ReplicaSetConfig.Name)));
}
else
{
if (_maxElectionInfo.SetVersion < args.NewServerDescription.ReplicaSetConfig.Version.Value)
{
_sdamInformationEventHandler?.Invoke(new SdamInformationEvent(() =>
string.Format(
@"Updating stale setVersion: Updating the current " +
@"(maxSetVersion, maxElectionId) tuple from ({0}, {1}) to ({2}, {3}) for " +
@"replica set ""{4}"" because replica set primary {5} sent ({6}, {7})—a larger " +
@"(setVersion, electionId) tuple then the saved tuple, ({0}, {1}).",
_maxElectionInfo.SetVersion,
_maxElectionInfo.ElectionId,
args.NewServerDescription.ReplicaSetConfig.Version,
args.NewServerDescription.ElectionId,
args.NewServerDescription.ReplicaSetConfig.Name,
args.NewServerDescription.EndPoint,
args.NewServerDescription.ReplicaSetConfig.Version,
args.NewServerDescription.ElectionId)));
}
else // current primary is stale & setVersion is not stale ⇒ the electionId must be stale
{
_sdamInformationEventHandler?.Invoke(new SdamInformationEvent(() =>
string.Format(
@"Updating stale electionId: Updating the current " +
@"(maxSetVersion, maxElectionId) tuple from ({0}, {1}) to ({2}, {3}) for " +
@"replica set ""{4}"" because replica set primary {5} sent ({6}, {7})—" +
@"a larger (setVersion, electionId) tuple than the saved tuple, ({0}, {1}).",
_maxElectionInfo.SetVersion,
_maxElectionInfo.ElectionId,
args.NewServerDescription.ReplicaSetConfig.Version,
args.NewServerDescription.ElectionId,
args.NewServerDescription.ReplicaSetConfig.Name,
args.NewServerDescription.EndPoint,
args.NewServerDescription.ReplicaSetConfig.Version,
args.NewServerDescription.ElectionId)));
}
}
_maxElectionInfo = new ElectionInfo(
args.NewServerDescription.ReplicaSetConfig.Version.Value,
args.NewServerDescription.ElectionId);
}
}
var currentPrimaryEndPoints = clusterDescription.Servers
.Where(x => x.Type == ServerType.ReplicaSetPrimary)
.Where(x => !EndPointHelper.Equals(x.EndPoint, args.NewServerDescription.EndPoint))
.Select(x => x.EndPoint)
.ToList();
if (currentPrimaryEndPoints.Count > 0)
{
lock (_serversLock)
{
var currentPrimaries = _servers.Where(x => EndPointHelper.Contains(currentPrimaryEndPoints, x.EndPoint));
foreach (var currentPrimary in currentPrimaries)
{
// kick off the server to invalidate itself
currentPrimary.Invalidate();
// set it to disconnected in the cluster
clusterDescription = clusterDescription.WithServerDescription(
new ServerDescription(currentPrimary.ServerId, currentPrimary.EndPoint));
}
}
}
}
return(clusterDescription);
}
private ClusterDescription ProcessReplicaSetChange(ClusterDescription clusterDescription, ServerDescriptionChangedEventArgs args, List <IClusterableServer> newServers)
{
if (!args.NewServerDescription.Type.IsReplicaSetMember())
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, string.Format("Server is a {0}, not a replica set member.", args.NewServerDescription.Type)));
}
if (args.NewServerDescription.Type == ServerType.ReplicaSetGhost)
{
return(clusterDescription.WithServerDescription(args.NewServerDescription));
}
if (_replicaSetName == null)
{
_replicaSetName = args.NewServerDescription.ReplicaSetConfig.Name;
}
if (_replicaSetName != args.NewServerDescription.ReplicaSetConfig.Name)
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, string.Format("Server was a member of the '{0}' replica set, but should be '{1}'.", args.NewServerDescription.ReplicaSetConfig.Name, _replicaSetName)));
}
clusterDescription = clusterDescription.WithServerDescription(args.NewServerDescription);
clusterDescription = EnsureServers(clusterDescription, args.NewServerDescription, newServers);
if (args.NewServerDescription.CanonicalEndPoint != null &&
!EndPointHelper.Equals(args.NewServerDescription.CanonicalEndPoint, args.NewServerDescription.EndPoint))
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, "CanonicalEndPoint is different than seed list EndPoint."));
}
if (args.NewServerDescription.Type == ServerType.ReplicaSetPrimary)
{
if (args.NewServerDescription.ReplicaSetConfig.Version != null)
{
bool isCurrentPrimaryStale = true;
if (_maxElectionInfo != null)
{
isCurrentPrimaryStale = _maxElectionInfo.IsStale(args.NewServerDescription.ReplicaSetConfig.Version.Value, args.NewServerDescription.ElectionId);
var isReportedPrimaryStale = !isCurrentPrimaryStale;
if (isReportedPrimaryStale && args.NewServerDescription.ElectionId != null)
{
// we only invalidate the "newly" reported stale primary if electionId was used.
lock (_serversLock)
{
var server = _servers.SingleOrDefault(x => EndPointHelper.Equals(args.NewServerDescription.EndPoint, x.EndPoint));
server.Invalidate();
return(clusterDescription.WithServerDescription(
new ServerDescription(server.ServerId, server.EndPoint)));
}
}
}
if (isCurrentPrimaryStale)
{
_maxElectionInfo = new ElectionInfo(
args.NewServerDescription.ReplicaSetConfig.Version.Value,
args.NewServerDescription.ElectionId);
}
}
var currentPrimaryEndPoints = clusterDescription.Servers
.Where(x => x.Type == ServerType.ReplicaSetPrimary)
.Where(x => !EndPointHelper.Equals(x.EndPoint, args.NewServerDescription.EndPoint))
.Select(x => x.EndPoint)
.ToList();
if (currentPrimaryEndPoints.Count > 0)
{
lock (_serversLock)
{
var currentPrimaries = _servers.Where(x => EndPointHelper.Contains(currentPrimaryEndPoints, x.EndPoint));
foreach (var currentPrimary in currentPrimaries)
{
// kick off the server to invalidate itself
currentPrimary.Invalidate();
// set it to disconnected in the cluster
clusterDescription = clusterDescription.WithServerDescription(
new ServerDescription(currentPrimary.ServerId, currentPrimary.EndPoint));
}
}
}
}
return(clusterDescription);
}
private ClusterDescription ProcessReplicaSetChange(ClusterDescription clusterDescription, ServerDescriptionChangedEventArgs args)
{
if (!args.NewServerDescription.Type.IsReplicaSetMember())
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, string.Format("Server is a {0}, not a replica set member.", args.NewServerDescription.Type)));
}
if (args.NewServerDescription.Type == ServerType.ReplicaSetGhost)
{
return(clusterDescription.WithServerDescription(args.NewServerDescription));
}
if (_replicaSetName == null)
{
_replicaSetName = args.NewServerDescription.ReplicaSetConfig.Name;
}
if (_replicaSetName != args.NewServerDescription.ReplicaSetConfig.Name)
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, string.Format("Server was a member of the '{0}' replica set, but should be '{1}'.", args.NewServerDescription.ReplicaSetConfig.Name, _replicaSetName)));
}
clusterDescription = clusterDescription.WithServerDescription(args.NewServerDescription);
clusterDescription = EnsureServers(clusterDescription, args.NewServerDescription);
if (args.NewServerDescription.CanonicalEndPoint != null &&
!EndPointHelper.Equals(args.NewServerDescription.CanonicalEndPoint, args.NewServerDescription.EndPoint))
{
return(RemoveServer(clusterDescription, args.NewServerDescription.EndPoint, "CanonicalEndPoint is different than seed list EndPoint."));
}
if (args.NewServerDescription.Type == ServerType.ReplicaSetPrimary)
{
if (args.NewServerDescription.ElectionId != null)
{
if (_maxElectionId != null && _maxElectionId.CompareTo(args.NewServerDescription.ElectionId) > 0)
{
// ignore this change because we've already seen this election id
lock (_serversLock)
{
var server = _servers.SingleOrDefault(x => EndPointHelper.Equals(args.NewServerDescription.EndPoint, x.EndPoint));
server.Invalidate();
return(clusterDescription.WithServerDescription(
new ServerDescription(server.ServerId, server.EndPoint)));
}
}
_maxElectionId = args.NewServerDescription.ElectionId;
}
var currentPrimaryEndPoints = clusterDescription.Servers
.Where(x => x.Type == ServerType.ReplicaSetPrimary)
.Where(x => !EndPointHelper.Equals(x.EndPoint, args.NewServerDescription.EndPoint))
.Select(x => x.EndPoint)
.ToList();
if (currentPrimaryEndPoints.Count > 0)
{
lock (_serversLock)
{
var currentPrimaries = _servers.Where(x => EndPointHelper.Contains(currentPrimaryEndPoints, x.EndPoint));
foreach (var currentPrimary in currentPrimaries)
{
// kick off the server to invalidate itself
currentPrimary.Invalidate();
// set it to disconnected in the cluster
clusterDescription = clusterDescription.WithServerDescription(
new ServerDescription(currentPrimary.ServerId, currentPrimary.EndPoint));
}
}
}
}
return(clusterDescription);
}
public IServer SelectServer()
{
lock (_cluster._descriptionLock)
{
_descriptionChangedTask = _cluster._descriptionChangedTaskCompletionSource.Task;
_description = _cluster._description;
}
if (!_serverSelectionWaitQueueEntered)
{
var selectingServerEventHandler = _cluster._selectingServerEventHandler;
if (selectingServerEventHandler != null)
{
// this is our first time through...
selectingServerEventHandler(new ClusterSelectingServerEvent(
_description,
_selector,
EventContext.OperationId));
}
}
MongoIncompatibleDriverException.ThrowIfNotSupported(_description);
_connectedServers.Clear();
_connectedServerDescriptions.Clear();
foreach (var description in _description.Servers)
{
if (description.State == ServerState.Connected &&
_cluster.TryGetServer(description.EndPoint, out var server))
{
_connectedServers.Add(server);
_connectedServerDescriptions.Add(description);
}
}
var selectedServersDescriptions = _selector
.SelectServers(_description, _connectedServerDescriptions)
.ToList();
IServer selectedServer = null;
if (selectedServersDescriptions.Count > 0)
{
var selectedServerDescription = selectedServersDescriptions.Count == 1
? selectedServersDescriptions[0]
: __randomServerSelector.SelectServers(_description, selectedServersDescriptions).Single();
selectedServer = _connectedServers.FirstOrDefault(s => EndPointHelper.Equals(s.EndPoint, selectedServerDescription.EndPoint));
}
if (selectedServer != null)
{
_stopwatch.Stop();
_cluster._selectedServerEventHandler?.Invoke(new ClusterSelectedServerEvent(
_description,
_selector,
selectedServer.Description,
_stopwatch.Elapsed,
EventContext.OperationId));
}
return(selectedServer);
}
