//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; }