/// <summary>
/// Refreshes the replication information.
/// Expert use only.
/// </summary>
public async Task RefreshReplicationInformationAsync(RavenFileSystemClient serverClient)
{
var serverHash = ServerHash.GetServerHash(serverClient.ServerUrl);
try
{
var result = await serverClient.Config.GetConfig(SynchronizationConstants.RavenSynchronizationDestinations);
if (result == null)
{
LastReplicationUpdate = SystemTime.UtcNow; // checked and not found
}
else
{
var urls = result.GetValues("url");
replicationDestinations = urls == null ? new List <string>() : urls.ToList();
}
}
catch (Exception e)
{
log.ErrorException("Could not contact master for new replication information", e);
replicationDestinations = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash).ToList();
LastReplicationUpdate = SystemTime.UtcNow;
return;
}
failureCounts[serverClient.ServerUrl] = new FailureCounter(); // we just hit the master, so we can reset its failure count
ReplicationInformerLocalCache.TrySavingReplicationInformationToLocalCache(serverHash, replicationDestinations);
UpdateReplicationInformationFromDocument(replicationDestinations);
LastReplicationUpdate = SystemTime.UtcNow;
}
//TODO: When counter replication will be refactored (simplified) -> the parameter should be removed; now its a constraint of the interface
public void RefreshReplicationInformation()
{
JsonDocument document;
var serverHash = ServerHash.GetServerHash(counterStore.Url);
try
{
var replicationFetchTask = counterStore.GetReplicationsAsync();
replicationFetchTask.Wait();
if (replicationFetchTask.Status != TaskStatus.Faulted)
{
failureCounters.ResetFailureCount(counterStore.Url);
}
document = new JsonDocument
{
DataAsJson = RavenJObject.FromObject(replicationFetchTask.Result)
};
}
catch (Exception e)
{
log.ErrorException("Could not contact master for fetching replication information. Something is wrong.", e);
document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
if (document == null || document.DataAsJson == null)
{
throw;
}
}
ReplicationInformerLocalCache.TrySavingReplicationInformationToLocalCache(serverHash, document);
UpdateReplicationInformationFromDocument(document);
}
public override void ClearReplicationInformationLocalCache(IAsyncFilesCommands client)
{
var serverClient = (IAsyncFilesCommandsImpl)client;
var urlForFilename = serverClient.UrlFor();
var serverHash = ServerHash.GetServerHash(urlForFilename);
ReplicationInformerLocalCache.ClearReplicationInformationFromLocalCache(serverHash);
}
/// <summary>
/// Initializes this instance.
/// </summary>
/// <returns></returns>
public IDocumentStore Initialize(bool ensureDatabaseExists)
{
if (initialized)
{
return(this);
}
AssertValidConfiguration();
jsonRequestFactory = new HttpJsonRequestFactory(MaxNumberOfCachedRequests, HttpMessageHandlerFactory, Conventions.AcceptGzipContent, Conventions.AuthenticationScheme);
try
{
SecurityExtensions.InitializeSecurity(Conventions, jsonRequestFactory, Url);
InitializeInternal();
if (Conventions.DocumentKeyGenerator == null)// don't overwrite what the user is doing
{
var generator = new MultiDatabaseHiLoGenerator(32);
Conventions.DocumentKeyGenerator = (dbName, databaseCommands, entity) => generator.GenerateDocumentKey(dbName, databaseCommands, Conventions, entity);
}
if (Conventions.AsyncDocumentKeyGenerator == null && asyncDatabaseCommandsGenerator != null)
{
var generator = new AsyncMultiDatabaseHiLoKeyGenerator(32);
Conventions.AsyncDocumentKeyGenerator = (dbName, commands, entity) => generator.GenerateDocumentKeyAsync(dbName, commands, Conventions, entity);
}
initialized = true;
#if !(MONO || DNXCORE50)
RecoverPendingTransactions();
#endif
if (ensureDatabaseExists &&
string.IsNullOrEmpty(DefaultDatabase) == false &&
DefaultDatabase.Equals(Constants.SystemDatabase) == false) //system database exists anyway
{
//If we have indication that the database is part of a replication cluster we don't want to create it,
//the reason for this is that we want the client to failover to a diffrent database.
var serverHash = ServerHash.GetServerHash(DatabaseCommands.Url);
var document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
var replicationDocument = document?.DataAsJson.JsonDeserialization <ReplicationDocumentWithClusterInformation>();
if (replicationDocument == null)
{
DatabaseCommands.ForSystemDatabase().GlobalAdmin.EnsureDatabaseExists(DefaultDatabase, true);
}
}
}
catch (Exception)
{
Dispose();
throw;
}
return(this);
}
public override Task UpdateReplicationInformationIfNeeded(IAsyncFilesCommands commands)
{
var serverClient = (IAsyncFilesCommandsImpl)commands;
if (conventions.FailoverBehavior == FailoverBehavior.FailImmediately)
{
return(new CompletedTask());
}
if (lastReplicationUpdate.AddMinutes(5) > SystemTime.UtcNow)
{
return(new CompletedTask());
}
lock (replicationLock)
{
if (firstTime)
{
var serverHash = ServerHash.GetServerHash(serverClient.ServerUrl);
var destinations = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
if (destinations != null)
{
UpdateReplicationInformationFromDocument(destinations);
}
}
firstTime = false;
if (lastReplicationUpdate.AddMinutes(5) > SystemTime.UtcNow)
{
return(new CompletedTask());
}
var taskCopy = refreshReplicationInformationTask;
if (taskCopy != null)
{
return(taskCopy);
}
return(refreshReplicationInformationTask = Task.Factory.StartNew(() => RefreshReplicationInformation(serverClient))
.ContinueWith(task =>
{
if (task.Exception != null)
{
log.ErrorException("Failed to refresh replication information", task.Exception);
}
refreshReplicationInformationTask = null;
}));
}
}
private Task UpdateReplicationInformationIfNeededInternal(IAsyncFilesCommands commands)
{
if (Conventions.FailoverBehavior == FailoverBehavior.FailImmediately)
{
return(new CompletedTask());
}
if (LastReplicationUpdate.AddMinutes(5) > SystemTime.UtcNow)
{
return(new CompletedTask());
}
var serverClient = (IAsyncFilesCommandsImpl)commands;
lock (ReplicationLock)
{
if (FirstTime)
{
var serverHash = ServerHash.GetServerHash(serverClient.UrlFor());
var document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
if (IsInvalidDestinationsDocument(document) == false)
{
UpdateReplicationInformationFromDocument(document);
}
}
FirstTime = false;
if (LastReplicationUpdate.AddMinutes(5) > SystemTime.UtcNow)
{
return(new CompletedTask());
}
var taskCopy = RefreshReplicationInformationTask;
if (taskCopy != null)
{
return(taskCopy);
}
return(RefreshReplicationInformationTask = Task.Factory.StartNew(() => RefreshReplicationInformation(commands))
.ContinueWith(task =>
{
if (task.Exception != null)
{
log.ErrorException("Failed to refresh replication information", task.Exception);
}
RefreshReplicationInformationTask = null;
}));
}
}
public Task UpdateReplicationInformationIfNeeded(RavenFileSystemClient serverClient)
#endif
{
if (Conventions.FailoverBehavior == FailoverBehavior.FailImmediately)
{
return(new CompletedTask());
}
if (LastReplicationUpdate.AddMinutes(5) > SystemTime.UtcNow)
{
return(new CompletedTask());
}
lock (replicationLock)
{
if (firstTime)
{
var serverHash = ServerHash.GetServerHash(serverClient.ServerUrl);
var destinations = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
if (destinations != null)
{
UpdateReplicationInformationFromDocument(destinations);
}
}
firstTime = false;
if (LastReplicationUpdate.AddMinutes(5) > SystemTime.UtcNow)
{
return(new CompletedTask());
}
var taskCopy = refreshReplicationInformationTask;
if (taskCopy != null)
{
return(taskCopy);
}
return(refreshReplicationInformationTask = RefreshReplicationInformationAsync(serverClient)
.ContinueWith(task =>
{
if (task.Exception != null)
{
log.ErrorException("Failed to refresh replication information", task.Exception);
}
refreshReplicationInformationTask = null;
}));
}
}
/// <summary>
/// Refreshes the replication information.
/// Expert use only.
/// </summary>
public override void RefreshReplicationInformation(IAsyncFilesCommands commands)
{
lock (this)
{
var serverClient = (IAsyncFilesCommandsImpl)commands;
string urlForFilename = serverClient.UrlFor();
var serverHash = ServerHash.GetServerHash(urlForFilename);
JsonDocument document = null;
try
{
var config = serverClient.Configuration.GetKeyAsync <RavenJObject>(SynchronizationConstants.RavenSynchronizationDestinations).Result;
failureCounts[urlForFilename] = new FailureCounter(); // we just hit the master, so we can reset its failure count
if (config != null)
{
var destinationsArray = config.Value <RavenJArray>("Destinations");
if (destinationsArray != null)
{
document = new JsonDocument();
document.DataAsJson = new RavenJObject()
{
{ "Destinations", destinationsArray }
};
}
}
}
catch (Exception e)
{
log.ErrorException("Could not contact master for new replication information", e);
document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
}
if (document == null)
{
lastReplicationUpdate = SystemTime.UtcNow; // checked and not found
return;
}
ReplicationInformerLocalCache.TrySavingReplicationInformationToLocalCache(serverHash, document);
UpdateReplicationInformationFromDocument(document);
lastReplicationUpdate = SystemTime.UtcNow;
}
}
private async Task UpdateTopology()
{
JsonOperationContext context;
using (ContextPool.AllocateOperationContext(out context))
{
var node = _topology.LeaderNode;
var serverHash = ServerHash.GetServerHash(node.Url, node.Database);
if (_firstTimeTryLoadFromTopologyCache)
{
_firstTimeTryLoadFromTopologyCache = false;
var cachedTopology = TopologyLocalCache.TryLoadTopologyFromLocalCache(serverHash, context);
if (cachedTopology != null && cachedTopology.Etag > 0)
{
_topology = cachedTopology;
// we have cached topology, but we need to verify it is up to date, we'll check in
// 1 second, and let the rest of the system start
_updateTopologyTimer.Change(TimeSpan.FromSeconds(1), Timeout.InfiniteTimeSpan);
return;
}
}
var command = new GetTopologyCommand();
try
{
await ExecuteAsync(new ChoosenNode { Node = node }, context, command);
if (_topology.Etag != command.Result.Etag)
{
_topology = command.Result;
TopologyLocalCache.TrySavingTopologyToLocalCache(serverHash, _topology, context);
}
}
catch (Exception ex)
{
if (Logger.IsInfoEnabled)
{
Logger.Info("Failed to update topology", ex);
}
}
finally
{
_updateTopologyTimer.Change(TimeSpan.FromMinutes(5), Timeout.InfiniteTimeSpan);
}
}
}
public Task UpdateReplicationInformationIfNeededAsync()
{
if (CountersConventions.FailoverBehavior == FailoverBehavior.FailImmediately)
{
return(new CompletedTask());
}
var updateInterval = TimeSpan.FromMilliseconds(MaxIntervalBetweenUpdatesInMilliseconds);
if (lastReplicationUpdate.AddMinutes(updateInterval.TotalMinutes) > SystemTime.UtcNow && firstTime == false)
{
return(new CompletedTask());
}
lock (updateReplicationInformationSyncObj)
{
if (!firstTime) //first time the local cache is obviously empty
{
var serverHash = ServerHash.GetServerHash(counterStore.Url);
var document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
if (IsInvalidDestinationsDocument(document) == false)
{
UpdateReplicationInformationFromDocument(document);
}
}
firstTime = false;
var taskCopy = refreshReplicationInformationTask;
if (taskCopy != null)
{
return(taskCopy);
}
return(refreshReplicationInformationTask =
Task.Factory.StartNew(RefreshReplicationInformation)
.ContinueWith(task =>
{
if (task.Exception != null)
{
log.ErrorException("Failed to refresh replication information", task.Exception);
}
lastReplicationUpdate = SystemTime.UtcNow;
refreshReplicationInformationTask = null;
}));
}
}
/// <summary>
/// Refreshes the replication information.
/// Expert use only.
/// </summary>
public override void RefreshReplicationInformation(IAsyncFilesCommands commands)
{
lock (this)
{
var serverClient = (IAsyncFilesCommandsImpl)commands;
var urlForFilename = serverClient.UrlFor();
var serverHash = ServerHash.GetServerHash(urlForFilename);
JsonDocument document = null;
try
{
var destinations = serverClient.Synchronization.GetDestinationsAsync().Result;
FailureCounters.FailureCounts[urlForFilename] = new FailureCounter(); // we just hit the master, so we can reset its failure count
if (destinations != null)
{
document = new JsonDocument
{
DataAsJson = new RavenJObject {
{ "Destinations", RavenJToken.FromObject(destinations) }
}
};
}
}
catch (Exception e)
{
Log.ErrorException("Could not contact master for new replication information", e);
document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
}
if (document == null)
{
lastReplicationUpdate = SystemTime.UtcNow;
ReplicationDestinations.Clear(); // clear destinations that could be retrieved from local storage
return;
}
if (IsInvalidDestinationsDocument(document) == false)
{
ReplicationInformerLocalCache.TrySavingReplicationInformationToLocalCache(serverHash, document);
UpdateReplicationInformationFromDocument(document);
}
lastReplicationUpdate = SystemTime.UtcNow;
}
}
public List <DocumentStore> CreateRaftCluster(int numberOfNodes, string activeBundles = null, Action <DocumentStore> configureStore = null, [CallerMemberName] string databaseName = null, bool inMemory = true, bool fiddler = false)
{
if (configureStore == null)
{
configureStore = defaultConfigureStore;
}
var nodes = Enumerable.Range(0, numberOfNodes)
.Select(x => GetNewServer(GetPort(), activeBundles: activeBundles, databaseName: databaseName, runInMemory: inMemory,
configureConfig: configuration =>
{
configuration.Cluster.ElectionTimeout *= 10;
configuration.Cluster.HeartbeatTimeout *= 10;
}))
.ToList();
var allNodesFinishedJoining = new ManualResetEventSlim();
var random = new Random();
var leader = nodes[random.Next(0, numberOfNodes - 1)];
leader.Options.ClusterManager.Value.InitializeTopology(forceCandidateState: true);
Assert.True(leader.Options.ClusterManager.Value.Engine.WaitForLeader(), "Leader was not elected by himself in time");
leader.Options.ClusterManager.Value.Engine.TopologyChanged += command =>
{
if (command.Requested.AllNodeNames.All(command.Requested.IsVoter))
{
allNodesFinishedJoining.Set();
}
};
for (var i = 0; i < numberOfNodes; i++)
{
var n = nodes[i];
if (n == leader)
{
continue;
}
Assert.True(leader.Options.ClusterManager.Value.Engine.AddToClusterAsync(new NodeConnectionInfo
{
Name = RaftHelper.GetNodeName(n.SystemDatabase.TransactionalStorage.Id),
Uri = RaftHelper.GetNodeUrl(n.SystemDatabase.Configuration.ServerUrl)
}).Wait(3000), "Failed to add node to cluster");
}
if (numberOfNodes == 1)
{
allNodesFinishedJoining.Set();
}
Assert.True(allNodesFinishedJoining.Wait(10000 * numberOfNodes), "Not all nodes become voters. " + leader.Options.ClusterManager.Value.Engine.CurrentTopology);
Assert.True(leader.Options.ClusterManager.Value.Engine.WaitForLeader(), "Wait for leader timedout");
WaitForClusterToBecomeNonStale(nodes);
foreach (var node in nodes)
{
var url = node.SystemDatabase.ServerUrl.ForDatabase(databaseName);
var serverHash = ServerHash.GetServerHash(url);
ReplicationInformerLocalCache.ClearClusterNodesInformationLocalCache(serverHash);
ReplicationInformerLocalCache.ClearReplicationInformationFromLocalCache(serverHash);
}
var documentStores = nodes
.Select(node => NewRemoteDocumentStore(ravenDbServer: node, fiddler: fiddler, activeBundles: activeBundles, configureStore: configureStore, databaseName: databaseName))
.ToList();
foreach (var documentStore in documentStores)
{
((ClusterAwareRequestExecuter)((ServerClient)documentStore.DatabaseCommands).RequestExecuter).WaitForLeaderTimeout = TimeSpan.FromSeconds(30);
}
return(documentStores);
}
private Task UpdateReplicationInformationForCluster(AsyncServerClient serverClient, OperationMetadata primaryNode, Func <OperationMetadata, Task <ReplicationDocumentWithClusterInformation> > getReplicationDestinationsTask)
{
lock (this)
{
var serverHash = ServerHash.GetServerHash(primaryNode.Url);
var taskCopy = refreshReplicationInformationTask;
if (taskCopy != null)
{
return(taskCopy);
}
if (firstTime)
{
firstTime = false;
var document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
var nodes = GetNodes(primaryNode, document?.DataAsJson.JsonDeserialization <ReplicationDocumentWithClusterInformation>());
if (nodes != null)
{
Nodes = nodes;
var newLeaderNode = GetLeaderNode(Nodes);
if (newLeaderNode != null)
{
if (Log.IsDebugEnabled)
{
Log.Debug($"Fetched topology from cache, Leader is {LeaderNode}\n Nodes:" + string.Join(",", Nodes.Select(n => n.Url)));
}
SetLeaderNodeToKnownLeader(newLeaderNode);
return(new CompletedTask());
}
if (Log.IsDebugEnabled)
{
Log.Debug($"Fetched topology from cache, no leader found.\n Nodes:" + string.Join(",", Nodes.Select(n => n.Url)));
}
SetLeaderNodeToNull();
}
}
return(refreshReplicationInformationTask = Task.Factory.StartNew(() =>
{
var tryFailoverServers = false;
var triedFailoverServers = FailoverServers == null || FailoverServers.Length == 0;
for (;;)
{
//taking a snapshot so we could tell if the value changed while we fetch the topology
var prevLeader = LeaderNode;
var nodes = NodeUrls.ToHashSet();
if (tryFailoverServers == false)
{
if (nodes.Count == 0)
{
nodes.Add(primaryNode);
}
}
else
{
nodes.Add(primaryNode); // always check primary node during failover check
foreach (var failoverServer in FailoverServers)
{
var node = ConvertReplicationDestinationToOperationMetadata(failoverServer, ClusterInformation.NotInCluster);
if (node != null)
{
nodes.Add(node);
}
}
triedFailoverServers = true;
}
var replicationDocuments = nodes
.Select(operationMetadata => new
{
Node = operationMetadata,
Task = getReplicationDestinationsTask(operationMetadata)
})
.ToArray();
var tasks = replicationDocuments
.Select(x => (Task)x.Task)
.ToArray();
var tasksCompleted = Task.WaitAll(tasks, ReplicationDestinationsTopologyTimeout);
if (Log.IsDebugEnabled && tasksCompleted == false)
{
Log.Debug($"During fetch topology {tasks.Count(t=>t.IsCompleted)} servers have responded out of {tasks.Length}");
}
replicationDocuments.ForEach(x =>
{
if (x.Task.IsCompleted && x.Task.Result != null)
{
FailureCounters.ResetFailureCount(x.Node.Url);
}
});
var newestTopology = replicationDocuments
.Where(x => x.Task.IsCompleted && x.Task.Result != null)
.OrderByDescending(x => x.Task.Result.Term)
.ThenByDescending(x =>
{
var index = x.Task.Result.ClusterCommitIndex;
return x.Task.Result.ClusterInformation.IsLeader ? index + 1 : index;
})
.FirstOrDefault();
if (newestTopology == null && FailoverServers != null && FailoverServers.Length > 0 && tryFailoverServers == false)
{
tryFailoverServers = true;
}
if (newestTopology == null && triedFailoverServers)
{
if (Log.IsDebugEnabled)
{
Log.Debug($"Fetching topology resulted with no topology, tried failoever servers, setting leader node to primary node ({primaryNode}).");
}
//if the leader Node is not null this means that somebody updated it, we don't want to overwrite it with the primary.
// i'm rasing the leader changed event although we don't have a real leader because some tests don't wait for leader but actually any node
//Todo: change back to: if (SetLeaderNodeIfLeaderIsNull(primaryNode, false) == false)
if (SetLeaderNodeIfLeaderIsNull(primaryNode) == false)
{
return;
}
if (Nodes.Count == 0)
{
Nodes = new List <OperationMetadata>
{
primaryNode
}
}
;
return;
}
if (newestTopology != null)
{
var replicationDocument = newestTopology.Task.Result;
var node = newestTopology.Node;
if (UpdateTopology(serverClient, node, replicationDocument, serverHash, prevLeader))
{
return;
}
}
Thread.Sleep(500);
}
}).ContinueWith(t =>
{
lastUpdate = SystemTime.UtcNow;
refreshReplicationInformationTask = null;
}));
}
}
private Task UpdateReplicationInformationForCluster(AsyncServerClient serverClient, OperationMetadata primaryNode, Func <OperationMetadata, Task <ReplicationDocumentWithClusterInformation> > getReplicationDestinationsTask)
{
lock (this)
{
var serverHash = ServerHash.GetServerHash(primaryNode.Url);
var taskCopy = refreshReplicationInformationTask;
if (taskCopy != null)
{
return(taskCopy);
}
if (firstTime)
{
firstTime = false;
var document = ReplicationInformerLocalCache.TryLoadReplicationInformationFromLocalCache(serverHash);
var nodes = GetNodes(primaryNode, document?.DataAsJson.JsonDeserialization <ReplicationDocumentWithClusterInformation>());
if (nodes != null)
{
Nodes = nodes;
var newLeaderNode = GetLeaderNode(Nodes);
if (newLeaderNode != null)
{
if (Log.IsDebugEnabled)
{
Log.Debug($"Fetched topology from cache, Leader is {LeaderNode}\n Nodes:" + string.Join(",", Nodes.Select(n => n.Url)));
}
SetLeaderNodeToKnownLeader(newLeaderNode);
return(new CompletedTask());
}
if (Log.IsDebugEnabled)
{
Log.Debug($"Fetched topology from cache, no leader found.\n Nodes:" + string.Join(",", Nodes.Select(n => n.Url)));
}
SetLeaderNodeToNull();
}
}
return(refreshReplicationInformationTask = Task.Factory.StartNew(async() =>
{
var tryFailoverServers = false;
var triedFailoverServers = FailoverServers == null || FailoverServers.Length == 0;
for (; ;)
{
//taking a snapshot so we could tell if the value changed while we fetch the topology
var prevLeader = LeaderNode;
var nodes = NodeUrls.ToHashSet();
if (tryFailoverServers == false)
{
if (nodes.Count == 0)
{
nodes.Add(primaryNode);
}
}
else
{
nodes.Add(primaryNode); // always check primary node during failover check
foreach (var failoverServer in FailoverServers)
{
var node = ConvertReplicationDestinationToOperationMetadata(failoverServer, ClusterInformation.NotInCluster);
if (node != null)
{
nodes.Add(node);
}
}
triedFailoverServers = true;
}
var replicationDocuments = nodes
.Select(operationMetadata => new
{
Node = operationMetadata,
Task = getReplicationDestinationsTask(operationMetadata),
})
.ToArray();
var tasks = replicationDocuments
.Select(x => (Task)x.Task)
.ToArray();
var tasksCompleted = Task.WaitAll(tasks, ReplicationDestinationsTopologyTimeout);
if (Log.IsDebugEnabled && tasksCompleted == false)
{
Log.Debug($"During fetch topology {tasks.Count(t => t.IsCompleted)} servers have responded out of {tasks.Length}");
}
replicationDocuments.ForEach(x =>
{
if (x.Task.IsCompleted && x.Task.Result != null)
{
FailureCounters.ResetFailureCount(x.Node.Url);
}
});
var newestTopologies = replicationDocuments
.Where(x => x.Task.IsCompleted && x.Task.Result != null)
.OrderByDescending(x => x.Task.Result.Term)
.ThenByDescending(x =>
{
var index = x.Task.Result.ClusterCommitIndex;
return x.Task.Result.ClusterInformation.IsLeader ? index + 1 : index;
}).ToList();
var newestTopology = newestTopologies.FirstOrDefault();
var hasLeaderCount = replicationDocuments
.Count(x => x.Task.IsCompleted && x.Task.Result != null && x.Task.Result.HasLeader);
if (newestTopology == null && FailoverServers != null && FailoverServers.Length > 0 && tryFailoverServers == false)
{
tryFailoverServers = true;
}
if (newestTopology == null && triedFailoverServers)
{
if (Log.IsDebugEnabled)
{
Log.Debug($"Fetching topology resulted with no topology, tried failoever servers, setting leader node to primary node ({primaryNode}).");
}
//if the leader Node is not null this means that somebody updated it, we don't want to overwrite it with the primary.
// i'm raising the leader changed event although we don't have a real leader because some tests don't wait for leader but actually any node
//Todo: change back to: if (SetLeaderNodeIfLeaderIsNull(primaryNode, false) == false)
if (SetLeaderNodeIfLeaderIsNull(primaryNode) == false)
{
return;
}
if (Nodes.Count == 0)
{
Nodes = new List <OperationMetadata>
{
primaryNode
}
}
;
return;
}
if (Log.IsDebugEnabled)
{
foreach (var x in replicationDocuments)
{
Log.Debug($"Topology fetched from {x.Node.Url}");
Log.Debug($"{JsonConvert.SerializeObject(x.Task?.Result)}");
}
}
var majorityOfNodesAgreeThereIsLeader = Nodes.Count == 1 || hasLeaderCount > (newestTopology?.Task.Result.Destinations.Count + 1) / 2;
if (newestTopology != null && majorityOfNodesAgreeThereIsLeader)
{
var replicationDocument = newestTopology.Task.Result;
var node = newestTopology.Node;
if (newestTopologies.Count > 1 && node.Url.Equals(serverClient.Url) == false)
{
// we got the replication document not from the primary url
// need to add the node url destination to the destinations
// (we know it exists since we have majority of nodes that agree on the leader)
// and remove the primary url destination from the destinations
var sourceNode = node;
var destination = replicationDocument.Destinations
.FirstOrDefault(x => DestinationUrl(x.Url, x.Database).Equals(serverClient.Url, StringComparison.OrdinalIgnoreCase));
if (destination != null)
{
replicationDocument.Destinations.Remove(destination);
// we need to update the cluster information of the primary url for this node
replicationDocument.ClusterInformation = destination.ClusterInformation;
node = ConvertReplicationDestinationToOperationMetadata(destination, destination.ClusterInformation);
}
destination = destination ?? replicationDocument.Destinations.FirstOrDefault();
if (destination != null)
{
var database = destination.Database;
var networkCredentials = sourceNode.Credentials?.Credentials as NetworkCredential;
replicationDocument.Destinations.Add(new ReplicationDestination.ReplicationDestinationWithClusterInformation
{
Url = sourceNode.Url,
Database = database,
ApiKey = sourceNode.Credentials?.ApiKey,
Username = networkCredentials?.UserName,
Password = networkCredentials?.Password,
Domain = networkCredentials?.Domain,
ClusterInformation = sourceNode.ClusterInformation
});
}
}
if (UpdateTopology(serverClient, node, replicationDocument, serverHash, prevLeader))
{
return;
}
}
await Task.Delay(3000).ConfigureAwait(false);
}
}).ContinueWith(t =>
{
lastUpdate = SystemTime.UtcNow;
refreshReplicationInformationTask = null;
}));
}
}
private Task UpdateReplicationInformationForCluster(OperationMetadata primaryNode, Func<OperationMetadata, Task<ReplicationDocumentWithClusterInformation>> getReplicationDestinationsTask)
{
lock (this)
{
var serverHash = ServerHash.GetServerHash(primaryNode.Url);
var taskCopy = refreshReplicationInformationTask;
if (taskCopy != null)
return taskCopy;
if (firstTime)
{
firstTime = false;
var nodes = ReplicationInformerLocalCache.TryLoadClusterNodesFromLocalCache(serverHash);
if (nodes != null)
{
Nodes = nodes;
LeaderNode = GetLeaderNode(Nodes);
if (LeaderNode != null)
return new CompletedTask();
}
}
return refreshReplicationInformationTask = Task.Factory.StartNew(() =>
{
var tryFailoverServers = false;
var triedFailoverServers = FailoverServers == null || FailoverServers.Length == 0;
for (; ; )
{
var nodes = NodeUrls.ToHashSet();
if (tryFailoverServers == false)
{
if (nodes.Count == 0)
nodes.Add(primaryNode);
}
else
{
nodes.Add(primaryNode); // always check primary node during failover check
foreach (var failoverServer in FailoverServers)
{
var node = ConvertReplicationDestinationToOperationMetadata(failoverServer, ClusterInformation.NotInCluster);
if (node != null)
nodes.Add(node);
}
triedFailoverServers = true;
}
var replicationDocuments = nodes
.Select(operationMetadata => new
{
Node = operationMetadata,
Task = getReplicationDestinationsTask(operationMetadata)
})
.ToArray();
var tasks = replicationDocuments
.Select(x => x.Task)
.ToArray();
Task.WaitAll(tasks);
replicationDocuments.ForEach(x =>
{
if (x.Task.Result == null)
return;
FailureCounters.ResetFailureCount(x.Node.Url);
});
var newestTopology = replicationDocuments
.Where(x => x.Task.Result != null)
.OrderByDescending(x => x.Task.Result.Term)
.ThenByDescending(x =>
{
var index = x.Task.Result.ClusterCommitIndex;
return x.Task.Result.ClusterInformation.IsLeader ? index + 1 : index;
})
.FirstOrDefault();
if (newestTopology == null && FailoverServers != null && FailoverServers.Length > 0 && tryFailoverServers == false)
tryFailoverServers = true;
if (newestTopology == null && triedFailoverServers)
{
LeaderNode = primaryNode;
Nodes = new List<OperationMetadata>
{
primaryNode
};
return;
}
if (newestTopology != null)
{
Nodes = GetNodes(newestTopology.Node, newestTopology.Task.Result);
LeaderNode = newestTopology.Task.Result.ClusterInformation.IsLeader ?
Nodes.FirstOrDefault(n => n.Url == newestTopology.Node.Url) : null;
ReplicationInformerLocalCache.TrySavingClusterNodesToLocalCache(serverHash, Nodes);
if (LeaderNode != null)
return;
}
Thread.Sleep(500);
}
}).ContinueWith(t =>
{
lastUpdate = SystemTime.UtcNow;
refreshReplicationInformationTask = null;
});
}
}