//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginUploadFromStream(System.IO.Stream source, AsyncCallback callback, object state)
//{
// return strongBlob.BeginUploadFromStream(source, callback, state);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginUploadFromStream(System.IO.Stream source, Microsoft.WindowsAzure.Storage.AccessCondition accessCondition, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options, Microsoft.WindowsAzure.Storage.OperationContext operationContext, AsyncCallback callback, object state)
//{
// return strongBlob.BeginUploadFromStream(source, accessCondition, options, operationContext, callback, state);
//}
//public void EndUploadFromStream(IAsyncResult asyncResult)
//{
// strongBlob.EndUploadFromStream(asyncResult);
// slaEngine.SessionState.RecordObjectWritten(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginDownloadToStream(System.IO.Stream target, AsyncCallback callback, object state)
//{
// // TODO: Use SLA to decide from which server to download.
// return strongBlob.BeginDownloadToStream(target, callback, state);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginDownloadToStream(System.IO.Stream target, Microsoft.WindowsAzure.Storage.AccessCondition accessCondition, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options, Microsoft.WindowsAzure.Storage.OperationContext operationContext, AsyncCallback callback, object state)
//{
// return strongBlob.BeginDownloadToStream(target, accessCondition, options, operationContext, callback, state);
//}
//public void EndDownloadToStream(IAsyncResult asyncResult)
//{
// strongBlob.EndDownloadToStream(asyncResult);
// slaEngine.SessionState.RecordObjectRead(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginDownloadRangeToStream(System.IO.Stream target, long? offset, long? length, AsyncCallback callback, object state)
//{
// return strongBlob.BeginDownloadRangeToStream(target, offset, length, callback, state);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginDownloadRangeToStream(System.IO.Stream target, long? offset, long? length, Microsoft.WindowsAzure.Storage.AccessCondition accessCondition, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options, Microsoft.WindowsAzure.Storage.OperationContext operationContext, AsyncCallback callback, object state)
//{
// return strongBlob.BeginDownloadRangeToStream(target, offset, length, accessCondition, options, operationContext, callback, state);
//}
//public void EndDownloadRangeToStream(IAsyncResult asyncResult)
//{
// strongBlob.EndDownloadRangeToStream(asyncResult);
// slaEngine.SessionState.RecordObjectRead(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginExists(AsyncCallback callback, object state)
//{
// return strongBlob.BeginExists(callback, state);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginExists(Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options, Microsoft.WindowsAzure.Storage.OperationContext operationContext, AsyncCallback callback, object state)
//{
// return strongBlob.BeginExists(options, operationContext, callback, state);
//}
//public bool EndExists(IAsyncResult asyncResult)
//{
// bool result = strongBlob.EndExists(asyncResult);
// slaEngine.SessionState.RecordObjectRead(strongBlob.Name, Timestamp(strongBlob), primaryServer);
// return result;
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginFetchAttributes(AsyncCallback callback, object state)
//{
// return strongBlob.BeginFetchAttributes(callback, state);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginFetchAttributes(Microsoft.WindowsAzure.Storage.AccessCondition accessCondition, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options, Microsoft.WindowsAzure.Storage.OperationContext operationContext, AsyncCallback callback, object state)
//{
// return strongBlob.BeginFetchAttributes(accessCondition, options, operationContext, callback, state);
//}
//public void EndFetchAttributes(IAsyncResult asyncResult)
//{
// strongBlob.EndFetchAttributes(asyncResult);
// slaEngine.SessionState.RecordObjectRead(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
//public void SetMetadata(Microsoft.WindowsAzure.Storage.AccessCondition accessCondition = null, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options = null, Microsoft.WindowsAzure.Storage.OperationContext operationContext = null)
//{
// watch.Start();
// strongBlob.SetMetadata(accessCondition, options, operationContext);
// primaryServer.AddRtt(watch.ElapsedMilliseconds);
// slaEngine.SessionState.RecordObjectWritten(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginSetMetadata(AsyncCallback callback, object state)
//{
// return strongBlob.BeginSetMetadata(callback, state);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginSetMetadata(Microsoft.WindowsAzure.Storage.AccessCondition accessCondition, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options, Microsoft.WindowsAzure.Storage.OperationContext operationContext, AsyncCallback callback, object state)
//{
// return strongBlob.BeginSetMetadata(accessCondition, options, operationContext, callback, state);
//}
//public void EndSetMetadata(IAsyncResult asyncResult)
//{
// strongBlob.EndSetMetadata(asyncResult);
// slaEngine.SessionState.RecordObjectWritten(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
//public void SetProperties(Microsoft.WindowsAzure.Storage.AccessCondition accessCondition = null, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options = null, Microsoft.WindowsAzure.Storage.OperationContext operationContext = null)
//{
// watch.Start();
// strongBlob.SetProperties(accessCondition, options, operationContext);
// primaryServer.AddRtt(watch.ElapsedMilliseconds);
// slaEngine.SessionState.RecordObjectWritten(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginSetProperties(AsyncCallback callback, object state)
//{
// return strongBlob.BeginSetProperties(callback, state);
//}
//public Microsoft.WindowsAzure.Storage.ICancellableAsyncResult BeginSetProperties(Microsoft.WindowsAzure.Storage.AccessCondition accessCondition, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options, Microsoft.WindowsAzure.Storage.OperationContext operationContext, AsyncCallback callback, object state)
//{
// return strongBlob.BeginSetProperties(accessCondition, options, operationContext, callback, state);
//}
//public void EndSetProperties(IAsyncResult asyncResult)
//{
// strongBlob.EndSetProperties(asyncResult);
// slaEngine.SessionState.RecordObjectWritten(strongBlob.Name, Timestamp(strongBlob), primaryServer);
//}
public void Delete(Microsoft.WindowsAzure.Storage.Blob.DeleteSnapshotsOption deleteSnapshotsOption = DeleteSnapshotsOption.None, Microsoft.WindowsAzure.Storage.AccessCondition accessCondition = null, Microsoft.WindowsAzure.Storage.Blob.BlobRequestOptions options = null, Microsoft.WindowsAzure.Storage.OperationContext operationContext = null)
{
bool isDone = false;
do
{
try
{
if (configuration.IsInFastMode())
{
DoDelete(deleteSnapshotsOption, accessCondition, options, operationContext);
isDone = true;
}
else
{
//We are not sure if reconfiguration is happening or not. We execute put in slow mode.
using (CloudBlobLease lease = new CloudBlobLease(configuration.Name, LeaseTakingPolicy.TryOnce))
{
if (lease.HasLease)
{
configuration.SyncWithCloud(ClientRegistry.GetConfigurationAccount());
DoDelete(deleteSnapshotsOption, accessCondition, options, operationContext);
isDone = true;
}
}
}
}
catch (StorageException ex)
{
throw ex;
}
catch (Exception ex)
{
throw ex;
}
} while (!isDone);
}
/// <summary>
/// Perform read optimistically and then verify configuration.
/// </summary>
/// <param name="op">The read operation</param>
/// <param name="blob">The blob being read</param>
/// <param name="ss">The chosen server</param>
/// <returns>whether the read succeeded; if not, then it should be tried again.</returns>
private void SlowRead(ReadOp op)
{
// TODO: Deal with the case that we try to read from a replica that is no longer a replica and the read fails
// In this case, the read should be retried after refreshing the configuration.
ServerState ss = null;
try
{
bool isDone = false;
do // until we enter fast mode or succeed at reading in slow mode with the correct configuration
{
ss = slaEngine.FindServerToRead(blobName);
blobForRead = ClientRegistry.GetCloudBlob(ss.Name, containerName, blobName);
// TODO: this should really check if the reader wants strong consistency
// It could be that eventual consistency is fine but the SLA Engine just happened to choose a primary server
// In this case, we can do a fast mode read since we don't care if the chosen server is no longer a primary
if (configuration.IsInFastMode() || !configuration.PrimaryServers.Contains(ss.Name))
{
// it is fine to read from the selected secondary replica
// or from a primary replica if we have now entered fast mode
FastRead(op);
isDone = true;
}
else
{
// read from the selected replica that we believe to be a primary replica
watch.Start();
op(blobForRead);
watch.Stop();
// then see if the configuration has changed and the selected replica is no longer primary
configuration.SyncWithCloud(ClientRegistry.GetConfigurationAccount());
// TODO: check the epoch number on the configuration to make sure that we have not missed a configuration.
// i.e. we need to make sure that the server from which we read did not become a secondary during our read,
// and then back to primary when we checked.
// TODO: maybe we should check that the read delivered a non-zero utility.
// It is possible that the configuration was so stale that a much better server could have been chosen.
if (configuration.PrimaryServers.Contains(ss.Name))
{
//We have contacted the primary replica, hence we are good to go.
slaEngine.RecordObjectRead(blobForRead.Name, Timestamp(blobForRead), ss, watch.ElapsedMilliseconds);
isDone = true;
}
isDone = false; // not done
}
} while (!isDone);
}
// TODO: decide if we need to catch any exceptions here or just let then propagate through
catch (StorageException se)
{
if (StorageExceptionCode.NotFound(se))
{
//blob is not found.
//this is fine because the replica might have removed.
//it simply returns, so client need to re-execute if this happens.
//We can also re-execute the read here, but for debugging purposes, it's simpler for the client to re-execute.
//Of course in real system, we need to re-execute at this level.
return;
}
// storage exceptions are passed through to the caller
throw;
}
catch (Exception ex)
{
if (ex.Message.Contains("Object reference not set to an instance of an object"))
{
return;
}
throw ex;
}
}
public static void Main(string[] args)
{
Console.CancelKeyPress += new ConsoleCancelEventHandler(Cancelled);
if (args.Length == 0)
{
args = new string[7];
//storage account locating configuration of given container
args[0] = "dbtsouthstorage"; // "devstoreaccount1";
// container name
args[1] = "testcontainer";
// the result folder name
args[2] = "folder1";
//sleep time between ticks in milliseconds.
args[3] = "90000";
//interval between configuration
args[4] = "2";
//duration of experiment in ticks
args[5] = "24";
//start tick for configuration
args[6] = "1";
}
configurationSite = args[0];
containerName = args[1];
resultFileFolderName = args[2];
sleepTimeBetweenTicks = Int32.Parse(args[3]);
ticksBetweenConfigurations = Int32.Parse(args[4]);
experimentDurationInTicks = Int32.Parse(args[5]);
startTickOfConfiguration = Int32.Parse(args[6]);
Dictionary <string, CloudStorageAccount> acounts = Account.GetStorageAccounts(true);
acounts.Remove("devstoreaccount1");
ClientRegistry.Init(acounts, Account.GetStorageAccounts(true)[configurationSite]);
ReplicaConfiguration configuration = ClientRegistry.GetConfiguration(containerName, false);
Configurator conf = new Configurator(containerName);
#region replicator
Replicator replicator = new Replicator(containerName);
replicator.Start();
#endregion
#region configurator
List <ConfigurationConstraint> constraints = new List <ConfigurationConstraint>();
//constraints.Add(new LocationConstraint(containerName, "dbteastasiastorage", LocationConstraintType.Replicate));
constraints.Add(new ReplicationFactorConstraint(containerName, configuration, 1, 2));
DateTime startTime = DateTime.Now;
Thread.Sleep(startTickOfConfiguration * sleepTimeBetweenTicks);
while (DateTime.Now.Subtract(startTime).TotalMilliseconds < (experimentDurationInTicks * sleepTimeBetweenTicks))
{
try
{
configuration = ClientRegistry.GetConfiguration(containerName, false);
Console.WriteLine("Starting to reconfigure. Current Epoch: " + configuration.Epoch);
conf.Configure(ClientRegistry.GetConfigurationAccount(), configuration.Epoch, configuration, constraints);
Console.WriteLine(Configurator.Logs);
Console.WriteLine(">>>>>>>>>>> Finished. Current Epoch: " + configuration.Epoch + "<<<<<<<<<<<<<<<<");
}
catch (Exception ex)
{
Console.WriteLine(ex.StackTrace);
}
Thread.Sleep(ticksBetweenConfigurations * sleepTimeBetweenTicks);
}
#endregion
return;
}
