// public methods
public override void Invalidate(string reasonInvalidated, bool clearConnectionPool, TopologyVersion topologyVersion)
{
if (clearConnectionPool)
{
ConnectionPool.Clear();
}
var newDescription = _baseDescription.With(
$"InvalidatedBecause:{reasonInvalidated}",
lastUpdateTimestamp: DateTime.UtcNow,
topologyVersion: topologyVersion);
SetDescription(newDescription);
// TODO: make the heartbeat request conditional so we adhere to this part of the spec
// > Network error when reading or writing: ... Clients MUST NOT request an immediate check of the server;
// > since application sockets are used frequently, a network error likely means the server has just become
// > unavailable, so an immediate refresh is likely to get a network error, too.
RequestHeartbeat();
}
private void Heartbeat(CancellationToken cancellationToken)
{
CommandWireProtocol <BsonDocument> helloProtocol = null;
bool processAnother = true;
while (processAnother && !cancellationToken.IsCancellationRequested)
{
HelloResult heartbeatHelloResult = null;
Exception heartbeatException = null;
var previousDescription = _currentDescription;
try
{
IConnection connection;
lock (_lock)
{
connection = _connection;
}
if (connection == null)
{
var initializedConnection = InitializeConnection(cancellationToken);
lock (_lock)
{
if (_state.Value == State.Disposed)
{
try { initializedConnection.Dispose(); } catch { }
throw new OperationCanceledException("The ServerMonitor has been disposed.");
}
_connection = initializedConnection;
heartbeatHelloResult = _connection.Description.HelloResult;
}
}
else
{
// If MoreToCome is true, that means we are streaming hello or legacy hello results and must
// continue using the existing helloProtocol object.
// Otherwise helloProtocol has either not been initialized or we may need to switch between
// heartbeat commands based on the last heartbeat response.
if (helloProtocol == null || helloProtocol.MoreToCome == false)
{
helloProtocol = InitializeHelloProtocol(connection, previousDescription?.HelloOk ?? false);
}
heartbeatHelloResult = GetHelloResult(connection, helloProtocol, cancellationToken);
}
}
catch (OperationCanceledException) when(cancellationToken.IsCancellationRequested)
{
return;
}
catch (Exception ex)
{
IConnection toDispose = null;
lock (_lock)
{
helloProtocol = null;
heartbeatException = ex;
_roundTripTimeMonitor.Reset();
toDispose = _connection;
_connection = null;
}
toDispose?.Dispose();
}
lock (_lock)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
}
ServerDescription newDescription;
if (heartbeatHelloResult != null)
{
var averageRoundTripTime = _roundTripTimeMonitor.Average;
var averageRoundTripTimeRounded = TimeSpan.FromMilliseconds(Math.Round(averageRoundTripTime.TotalMilliseconds));
newDescription = _baseDescription.With(
averageRoundTripTime: averageRoundTripTimeRounded,
canonicalEndPoint: heartbeatHelloResult.Me,
electionId: heartbeatHelloResult.ElectionId,
helloOk: heartbeatHelloResult.HelloOk,
lastWriteTimestamp: heartbeatHelloResult.LastWriteTimestamp,
logicalSessionTimeout: heartbeatHelloResult.LogicalSessionTimeout,
maxBatchCount: heartbeatHelloResult.MaxBatchCount,
maxDocumentSize: heartbeatHelloResult.MaxDocumentSize,
maxMessageSize: heartbeatHelloResult.MaxMessageSize,
replicaSetConfig: heartbeatHelloResult.GetReplicaSetConfig(),
state: ServerState.Connected,
tags: heartbeatHelloResult.Tags,
topologyVersion: heartbeatHelloResult.TopologyVersion,
type: heartbeatHelloResult.ServerType,
version: WireVersion.ToServerVersion(heartbeatHelloResult.MaxWireVersion),
wireVersionRange: new Range <int>(heartbeatHelloResult.MinWireVersion, heartbeatHelloResult.MaxWireVersion));
}
else
{
newDescription = _baseDescription.With(lastUpdateTimestamp: DateTime.UtcNow);
}
if (heartbeatException != null)
{
var topologyVersion = default(Optional <TopologyVersion>);
if (heartbeatException is MongoCommandException heartbeatCommandException)
{
topologyVersion = TopologyVersion.FromMongoCommandException(heartbeatCommandException);
}
newDescription = newDescription.With(heartbeatException: heartbeatException, topologyVersion: topologyVersion);
}
newDescription = newDescription.With(reasonChanged: "Heartbeat", lastHeartbeatTimestamp: DateTime.UtcNow);
lock (_lock)
{
cancellationToken.ThrowIfCancellationRequested();
SetDescription(newDescription);
}
processAnother =
// serverSupportsStreaming
(newDescription.Type != ServerType.Unknown && heartbeatHelloResult != null && heartbeatHelloResult.TopologyVersion != null) ||
// connectionIsStreaming
(helloProtocol != null && helloProtocol.MoreToCome) ||
// transitionedWithNetworkError
(IsNetworkError(heartbeatException) && previousDescription.Type != ServerType.Unknown);
}
bool IsNetworkError(Exception ex)
{
return(ex is MongoConnectionException mongoConnectionException && mongoConnectionException.IsNetworkException);
}
}
private async Task HeartbeatAsync(CancellationToken cancellationToken)
{
CommandWireProtocol <BsonDocument> isMasterProtocol = null;
bool processAnother = true;
while (processAnother && !cancellationToken.IsCancellationRequested)
{
IsMasterResult heartbeatIsMasterResult = null;
Exception heartbeatException = null;
var previousDescription = _currentDescription;
try
{
IConnection connection;
lock (_lock)
{
connection = _connection;
}
if (connection == null)
{
var initializedConnection = await InitializeConnectionAsync(cancellationToken).ConfigureAwait(false);
lock (_lock)
{
if (_state.Value == State.Disposed)
{
try { initializedConnection.Dispose(); } catch { }
throw new OperationCanceledException("The ServerMonitor has been disposed.");
}
_connection = initializedConnection;
_handshakeBuildInfoResult = _connection.Description.BuildInfoResult;
heartbeatIsMasterResult = _connection.Description.IsMasterResult;
}
}
else
{
isMasterProtocol = isMasterProtocol ?? InitializeIsMasterProtocol(connection);
heartbeatIsMasterResult = await GetIsMasterResultAsync(connection, isMasterProtocol, cancellationToken).ConfigureAwait(false);
}
}
catch (OperationCanceledException) when(cancellationToken.IsCancellationRequested)
{
return;
}
catch (Exception ex)
{
IConnection toDispose = null;
lock (_lock)
{
isMasterProtocol = null;
heartbeatException = ex;
_roundTripTimeMonitor.Reset();
toDispose = _connection;
_connection = null;
}
toDispose?.Dispose();
}
lock (_lock)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
}
ServerDescription newDescription;
if (heartbeatIsMasterResult != null)
{
if (_handshakeBuildInfoResult == null)
{
// we can be here only if there is a bug in the driver
throw new ArgumentNullException("BuildInfo has been lost.");
}
var averageRoundTripTime = _roundTripTimeMonitor.Average;
var averageRoundTripTimeRounded = TimeSpan.FromMilliseconds(Math.Round(averageRoundTripTime.TotalMilliseconds));
newDescription = _baseDescription.With(
averageRoundTripTime: averageRoundTripTimeRounded,
canonicalEndPoint: heartbeatIsMasterResult.Me,
electionId: heartbeatIsMasterResult.ElectionId,
lastWriteTimestamp: heartbeatIsMasterResult.LastWriteTimestamp,
logicalSessionTimeout: heartbeatIsMasterResult.LogicalSessionTimeout,
maxBatchCount: heartbeatIsMasterResult.MaxBatchCount,
maxDocumentSize: heartbeatIsMasterResult.MaxDocumentSize,
maxMessageSize: heartbeatIsMasterResult.MaxMessageSize,
replicaSetConfig: heartbeatIsMasterResult.GetReplicaSetConfig(),
state: ServerState.Connected,
tags: heartbeatIsMasterResult.Tags,
topologyVersion: heartbeatIsMasterResult.TopologyVersion,
type: heartbeatIsMasterResult.ServerType,
version: _handshakeBuildInfoResult.ServerVersion,
wireVersionRange: new Range <int>(heartbeatIsMasterResult.MinWireVersion, heartbeatIsMasterResult.MaxWireVersion));
}
else
{
newDescription = _baseDescription.With(lastUpdateTimestamp: DateTime.UtcNow);
}
if (heartbeatException != null)
{
var topologyVersion = default(Optional <TopologyVersion>);
if (heartbeatException is MongoCommandException heartbeatCommandException)
{
topologyVersion = TopologyVersion.FromMongoCommandException(heartbeatCommandException);
}
newDescription = newDescription.With(heartbeatException: heartbeatException, topologyVersion: topologyVersion);
}
newDescription = newDescription.With(reasonChanged: "Heartbeat", lastHeartbeatTimestamp: DateTime.UtcNow);
lock (_lock)
{
cancellationToken.ThrowIfCancellationRequested();
SetDescription(newDescription);
}
processAnother =
// serverSupportsStreaming
(newDescription.Type != ServerType.Unknown && heartbeatIsMasterResult != null && heartbeatIsMasterResult.TopologyVersion != null) ||
// connectionIsStreaming
(isMasterProtocol != null && isMasterProtocol.MoreToCome) ||
// transitionedWithNetworkError
(IsNetworkError(heartbeatException) && previousDescription.Type != ServerType.Unknown);
}
bool IsNetworkError(Exception ex)
{
return(ex is MongoConnectionException mongoConnectionException && mongoConnectionException.IsNetworkException);
}
}
// protected methods
protected abstract void Invalidate(string reasonInvalidated, bool clearConnectionPool, TopologyVersion responseTopologyDescription);
public void Invalidate(string reasonInvalidated, TopologyVersion responseTopologyDescription)
{
Invalidate(reasonInvalidated, clearConnectionPool: true, responseTopologyDescription);
}
private bool ShouldInvalidateServer(
IConnection connection,
Exception exception,
ServerDescription description,
out TopologyVersion invalidatingResponseTopologyVersion)
{
if (exception is MongoConnectionException mongoConnectionException &&
mongoConnectionException.ContainsSocketTimeoutException)
{
invalidatingResponseTopologyVersion = null;
return(false);
}
if (__invalidatingExceptions.Contains(exception.GetType()))
{
invalidatingResponseTopologyVersion = null;
return(true);
}
var commandException = exception as MongoCommandException;
if (commandException != null)
{
var code = (ServerErrorCode)commandException.Code;
var message = commandException.ErrorMessage;
if (IsStateChangeError(code, message))
{
return(!IsStaleStateChangeError(commandException.Result, out invalidatingResponseTopologyVersion));
}
if (commandException.GetType() == typeof(MongoWriteConcernException))
{
var writeConcernException = (MongoWriteConcernException)commandException;
var writeConcernResult = writeConcernException.WriteConcernResult;
var response = writeConcernResult.Response;
var writeConcernError = response["writeConcernError"].AsBsonDocument;
if (writeConcernError != null)
{
code = (ServerErrorCode)writeConcernError.GetValue("code", -1).ToInt32();
message = writeConcernError.GetValue("errmsg", null)?.AsString;
if (IsStateChangeError(code, message))
{
return(!IsStaleStateChangeError(commandException.Result, out invalidatingResponseTopologyVersion));
}
}
}
}
invalidatingResponseTopologyVersion = null;
return(false);
bool IsStaleStateChangeError(BsonDocument response, out TopologyVersion nonStaleResponseTopologyVersion)
{
if (_connectionPool.Generation > connection.Generation)
{
// stale generation number
nonStaleResponseTopologyVersion = null;
return(true);
}
var responseTopologyVersion = TopologyVersion.FromMongoCommandResponse(response);
// We use FresherThanOrEqualTo instead of FresherThan because a state change should come with a new
// topology version.
// We cannot use StalerThan(responseTopologyVersion, description.TopologyVersion) because due to how
// TopologyVersions comparisons are defined, FresherThanOrEqualTo(x, y) does not imply StalerThan(y, x)
bool isStale = TopologyVersion.IsFresherThanOrEqualTo(description.TopologyVersion, responseTopologyVersion);
nonStaleResponseTopologyVersion = isStale ? null : responseTopologyVersion;
return(isStale);
}
}