/// <summary>
/// Starts the HTTP streaming connection to the Couchbase Server and gets the latest configuration for a SASL authenticated Bucket.
/// </summary>
/// <param name="bucketName">The name of the Couchbase Bucket.</param>
/// <param name="password">The SASL password used to connect to the Bucket.</param>
/// <returns>A <see cref="IConfigInfo"/> object representing the latest configuration.</returns>
public override IConfigInfo GetConfig(string bucketName, string password)
{
var bucketConfiguration = GetOrCreateConfiguration(bucketName);
StartProvider(bucketName, password);
var bucketConfig = GetBucketConfig(bucketName, password);
try
{
ConfigLock.EnterWriteLock();
IConfigInfo configInfo = null;
var nodes = bucketConfig.Nodes.ToList();
while (nodes.Any())
{
try
{
nodes.Shuffle();
var node = nodes.First();
nodes.Remove(node);
IBucketConfig newConfig;
var uri = bucketConfig.GetTerseUri(node, bucketConfiguration.UseSsl);
using (new SynchronizationContextExclusion())
{
using (var httpClient = new CouchbaseHttpClient(bucketName, password))
{
var body = httpClient.GetStringAsync(uri).Result;
body = body.Replace("$HOST", uri.Host);
newConfig = JsonConvert.DeserializeObject<BucketConfig>(body);
}
}
newConfig.Password = password;
configInfo = CreateConfigInfo(newConfig);
Configs[bucketName] = configInfo;
break;
}
catch (AggregateException e)
{
Log.Error(e.InnerException);
}
catch (IOException e)
{
Log.Error(e);
}
}
if (configInfo == null)
{
throw new BucketNotFoundException();
}
return configInfo;
}
finally
{
ConfigLock.ExitWriteLock();
}
}
/// <summary>
/// Starts the streaming connection to couchbase server that will
/// listen for configuration changes and then update the client as needed.
/// </summary>
/// <remarks>
/// Should not be used when a <see cref="SynchronizationContext" /> is present on the thread, as this
/// could cause deadlocks. This method is currently only used from within a dedicated thread,
/// created by <see cref="HttpStreamingProvider.RegisterObserver"/>, so it is safe because there will not
/// be a SynchronizationContext present on the thread.
/// </remarks>
public void ListenForConfigChanges()
{
var count = 0;
//Make a copy of the nodes and shuffle them for randomness
var nodes = _bucketConfig.Nodes.ToList();
using (var httpClient = new CouchbaseHttpClient(_bucketConfig.Name, _bucketConfig.Password))
{
httpClient.Timeout = Timeout.InfiniteTimeSpan;
//This will keep trying until it runs out of servers to try in the cluster
while (nodes.ToList().Any())
{
try
{
//If the main thread has canceled, break out of the loop otherwise
//the next node in the server list will be tried; but in this case
//we want to shut things down and terminate the thread
if (_cancellationToken.IsCancellationRequested)
{
break;
}
nodes = nodes.Shuffle();
var node = nodes[0];
nodes.Remove(node);
var streamingUri = _bucketConfig.GetTerseStreamingUri(node, _bucketConfig.UseSsl);
Log.Info(m => m("Listening to {0}", streamingUri));
var response =
httpClient.GetAsync(streamingUri, HttpCompletionOption.ResponseHeadersRead,
_cancellationToken)
.Result;
response.EnsureSuccessStatusCode();
using (var stream = response.Content.ReadAsStreamAsync().Result)
{
//this will cancel the infinite wait below
_cancellationToken.Register(stream.Dispose);
stream.ReadTimeout = Timeout.Infinite;
using (var reader = new StreamReader(stream, Encoding.UTF8, false))
{
string config;
while (!_cancellationToken.IsCancellationRequested &&
((config = reader.ReadLineAsync().Result) != null))
{
if (config != String.Empty)
{
Log.Info(m => m("configuration changed count: {0}", count++));
Log.Info(m => m("Worker Thread: {0}", Thread.CurrentThread.ManagedThreadId));
var config1 = config;
Log.Debug(m => m("{0}", config1));
config = config.Replace("$HOST", streamingUri.Host);
var bucketConfig = JsonConvert.DeserializeObject<BucketConfig>(config);
bucketConfig.SurrogateHost = GetSurrogateHost(streamingUri);
if (_configChangedDelegate != null)
{
bucketConfig.Password = _bucketConfig.Password;
_configChangedDelegate(bucketConfig);
}
}
}
}
}
}
catch (AggregateException e)
{
var exceptions = e.Flatten().InnerExceptions;
if (exceptions.OfType<ObjectDisposedException>().Any())
{
Log.Info("The config listener has shut down.");
}
foreach (var ex in exceptions.Where(x => x.GetType() != typeof(ObjectDisposedException)))
{
Log.Error(ex);
}
}
catch (Exception e)
{
Log.Error(e);
}
}
}
//We tried all nodes in the current configuration, alert the provider that we
//need to try to re-bootstrap from the beginning
if (nodes.Count == 0)
{
_errorOccurredDelegate(_bucketConfig);
}
}
