コード例 #1
0
        /// <exception cref="System.IO.IOException"/>
        private void OnAppend(ChannelHandlerContext ctx)
        {
            WriteContinueHeader(ctx);
            string       nnId       = @params.NamenodeId();
            int          bufferSize = @params.BufferSize();
            DFSClient    dfsClient  = NewDfsClient(nnId, conf);
            OutputStream @out       = dfsClient.Append(path, bufferSize, EnumSet.Of(CreateFlag.Append
                                                                                    ), null, null);
            DefaultHttpResponse resp = new DefaultHttpResponse(HttpVersion.Http11, HttpResponseStatus
                                                               .Ok);

            resp.Headers().Set(HttpHeaders.Names.ContentLength, 0);
            ctx.Pipeline().Replace(this, typeof(HdfsWriter).Name, new HdfsWriter(dfsClient, @out
                                                                                 , resp));
        }
コード例 #2
0
ファイル: WriteManager.cs プロジェクト: orf53975/hadoop.net
        /// <exception cref="System.IO.IOException"/>
        internal virtual void HandleWrite(DFSClient dfsClient, WRITE3Request request, Org.Jboss.Netty.Channel.Channel
                                          channel, int xid, Nfs3FileAttributes preOpAttr)
        {
            int count = request.GetCount();

            byte[] data = ((byte[])request.GetData().Array());
            if (data.Length < count)
            {
                WRITE3Response response = new WRITE3Response(Nfs3Status.Nfs3errInval);
                Nfs3Utils.WriteChannel(channel, response.Serialize(new XDR(), xid, new VerifierNone
                                                                       ()), xid);
                return;
            }
            FileHandle handle = request.GetHandle();

            if (Log.IsDebugEnabled())
            {
                Log.Debug("handleWrite " + request);
            }
            // Check if there is a stream to write
            FileHandle  fileHandle  = request.GetHandle();
            OpenFileCtx openFileCtx = fileContextCache.Get(fileHandle);

            if (openFileCtx == null)
            {
                Log.Info("No opened stream for fileId: " + fileHandle.GetFileId());
                string fileIdPath               = Nfs3Utils.GetFileIdPath(fileHandle.GetFileId());
                HdfsDataOutputStream fos        = null;
                Nfs3FileAttributes   latestAttr = null;
                try
                {
                    int bufferSize = config.GetInt(CommonConfigurationKeysPublic.IoFileBufferSizeKey,
                                                   CommonConfigurationKeysPublic.IoFileBufferSizeDefault);
                    fos = dfsClient.Append(fileIdPath, bufferSize, EnumSet.Of(CreateFlag.Append), null
                                           , null);
                    latestAttr = Nfs3Utils.GetFileAttr(dfsClient, fileIdPath, iug);
                }
                catch (RemoteException e)
                {
                    IOException io = e.UnwrapRemoteException();
                    if (io is AlreadyBeingCreatedException)
                    {
                        Log.Warn("Can't append file: " + fileIdPath + ". Possibly the file is being closed. Drop the request: "
                                 + request + ", wait for the client to retry...");
                        return;
                    }
                    throw;
                }
                catch (IOException e)
                {
                    Log.Error("Can't append to file: " + fileIdPath, e);
                    if (fos != null)
                    {
                        fos.Close();
                    }
                    WccData        fileWcc  = new WccData(Nfs3Utils.GetWccAttr(preOpAttr), preOpAttr);
                    WRITE3Response response = new WRITE3Response(Nfs3Status.Nfs3errIo, fileWcc, count
                                                                 , request.GetStableHow(), Nfs3Constant.WriteCommitVerf);
                    Nfs3Utils.WriteChannel(channel, response.Serialize(new XDR(), xid, new VerifierNone
                                                                           ()), xid);
                    return;
                }
                // Add open stream
                string writeDumpDir = config.Get(NfsConfigKeys.DfsNfsFileDumpDirKey, NfsConfigKeys
                                                 .DfsNfsFileDumpDirDefault);
                openFileCtx = new OpenFileCtx(fos, latestAttr, writeDumpDir + "/" + fileHandle.GetFileId
                                                  (), dfsClient, iug, aixCompatMode, config);
                if (!AddOpenFileStream(fileHandle, openFileCtx))
                {
                    Log.Info("Can't add new stream. Close it. Tell client to retry.");
                    try
                    {
                        fos.Close();
                    }
                    catch (IOException e)
                    {
                        Log.Error("Can't close stream for fileId: " + handle.GetFileId(), e);
                    }
                    // Notify client to retry
                    WccData        fileWcc  = new WccData(latestAttr.GetWccAttr(), latestAttr);
                    WRITE3Response response = new WRITE3Response(Nfs3Status.Nfs3errJukebox, fileWcc,
                                                                 0, request.GetStableHow(), Nfs3Constant.WriteCommitVerf);
                    Nfs3Utils.WriteChannel(channel, response.Serialize(new XDR(), xid, new VerifierNone
                                                                           ()), xid);
                    return;
                }
                if (Log.IsDebugEnabled())
                {
                    Log.Debug("Opened stream for appending file: " + fileHandle.GetFileId());
                }
            }
            // Add write into the async job queue
            openFileCtx.ReceivedNewWrite(dfsClient, request, channel, xid, asyncDataService,
                                         iug);
            return;
        }
コード例 #3
0
        /// <summary>Tests all FsEditLogOps that are converted to inotify events.</summary>
        /// <exception cref="System.IO.IOException"/>
        /// <exception cref="Sharpen.URISyntaxException"/>
        /// <exception cref="System.Exception"/>
        /// <exception cref="Org.Apache.Hadoop.Hdfs.Inotify.MissingEventsException"/>
        public virtual void TestBasic()
        {
            Configuration conf = new HdfsConfiguration();

            conf.SetLong(DFSConfigKeys.DfsBlockSizeKey, BlockSize);
            conf.SetBoolean(DFSConfigKeys.DfsNamenodeAclsEnabledKey, true);
            // so that we can get an atime change
            conf.SetLong(DFSConfigKeys.DfsNamenodeAccesstimePrecisionKey, 1);
            MiniQJMHACluster.Builder builder = new MiniQJMHACluster.Builder(conf);
            builder.GetDfsBuilder().NumDataNodes(2);
            MiniQJMHACluster cluster = builder.Build();

            try
            {
                cluster.GetDfsCluster().WaitActive();
                cluster.GetDfsCluster().TransitionToActive(0);
                DFSClient client = new DFSClient(cluster.GetDfsCluster().GetNameNode(0).GetNameNodeAddress
                                                     (), conf);
                FileSystem fs = cluster.GetDfsCluster().GetFileSystem(0);
                DFSTestUtil.CreateFile(fs, new Path("/file"), BlockSize, (short)1, 0L);
                DFSTestUtil.CreateFile(fs, new Path("/file3"), BlockSize, (short)1, 0L);
                DFSTestUtil.CreateFile(fs, new Path("/file5"), BlockSize, (short)1, 0L);
                DFSInotifyEventInputStream eis = client.GetInotifyEventStream();
                client.Rename("/file", "/file4", null);
                // RenameOp -> RenameEvent
                client.Rename("/file4", "/file2");
                // RenameOldOp -> RenameEvent
                // DeleteOp, AddOp -> UnlinkEvent, CreateEvent
                OutputStream os = client.Create("/file2", true, (short)2, BlockSize);
                os.Write(new byte[BlockSize]);
                os.Close();
                // CloseOp -> CloseEvent
                // AddOp -> AppendEvent
                os = client.Append("/file2", BlockSize, EnumSet.Of(CreateFlag.Append), null, null
                                   );
                os.Write(new byte[BlockSize]);
                os.Close();
                // CloseOp -> CloseEvent
                Sharpen.Thread.Sleep(10);
                // so that the atime will get updated on the next line
                client.Open("/file2").Read(new byte[1]);
                // TimesOp -> MetadataUpdateEvent
                // SetReplicationOp -> MetadataUpdateEvent
                client.SetReplication("/file2", (short)1);
                // ConcatDeleteOp -> AppendEvent, UnlinkEvent, CloseEvent
                client.Concat("/file2", new string[] { "/file3" });
                client.Delete("/file2", false);
                // DeleteOp -> UnlinkEvent
                client.Mkdirs("/dir", null, false);
                // MkdirOp -> CreateEvent
                // SetPermissionsOp -> MetadataUpdateEvent
                client.SetPermission("/dir", FsPermission.ValueOf("-rw-rw-rw-"));
                // SetOwnerOp -> MetadataUpdateEvent
                client.SetOwner("/dir", "username", "groupname");
                client.CreateSymlink("/dir", "/dir2", false);
                // SymlinkOp -> CreateEvent
                client.SetXAttr("/file5", "user.field", Sharpen.Runtime.GetBytesForString("value"
                                                                                          ), EnumSet.Of(XAttrSetFlag.Create));
                // SetXAttrOp -> MetadataUpdateEvent
                // RemoveXAttrOp -> MetadataUpdateEvent
                client.RemoveXAttr("/file5", "user.field");
                // SetAclOp -> MetadataUpdateEvent
                client.SetAcl("/file5", AclEntry.ParseAclSpec("user::rwx,user:foo:rw-,group::r--,other::---"
                                                              , true));
                client.RemoveAcl("/file5");
                // SetAclOp -> MetadataUpdateEvent
                client.Rename("/file5", "/dir");
                // RenameOldOp -> RenameEvent
                EventBatch batch = null;
                // RenameOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                long txid = batch.GetTxid();
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Rename);
                Event.RenameEvent re = (Event.RenameEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.AreEqual("/file4", re.GetDstPath());
                NUnit.Framework.Assert.AreEqual("/file", re.GetSrcPath());
                NUnit.Framework.Assert.IsTrue(re.GetTimestamp() > 0);
                long eventsBehind = eis.GetTxidsBehindEstimate();
                // RenameOldOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Rename);
                Event.RenameEvent re2 = (Event.RenameEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(re2.GetDstPath().Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(re2.GetSrcPath().Equals("/file4"));
                NUnit.Framework.Assert.IsTrue(re.GetTimestamp() > 0);
                // AddOp with overwrite
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Create);
                Event.CreateEvent ce = (Event.CreateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(ce.GetiNodeType() == Event.CreateEvent.INodeType.File
                                              );
                NUnit.Framework.Assert.IsTrue(ce.GetPath().Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(ce.GetCtime() > 0);
                NUnit.Framework.Assert.IsTrue(ce.GetReplication() > 0);
                NUnit.Framework.Assert.IsTrue(ce.GetSymlinkTarget() == null);
                NUnit.Framework.Assert.IsTrue(ce.GetOverwrite());
                NUnit.Framework.Assert.AreEqual(BlockSize, ce.GetDefaultBlockSize());
                // CloseOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Close);
                Event.CloseEvent ce2 = (Event.CloseEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(ce2.GetPath().Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(ce2.GetFileSize() > 0);
                NUnit.Framework.Assert.IsTrue(ce2.GetTimestamp() > 0);
                // AppendOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Append);
                Event.AppendEvent append2 = (Event.AppendEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.AreEqual("/file2", append2.GetPath());
                NUnit.Framework.Assert.IsFalse(append2.ToNewBlock());
                // CloseOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Close);
                NUnit.Framework.Assert.IsTrue(((Event.CloseEvent)batch.GetEvents()[0]).GetPath().
                                              Equals("/file2"));
                // TimesOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue.GetPath().Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(mue.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Times);
                // SetReplicationOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue2 = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue2.GetPath().Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(mue2.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Replication);
                NUnit.Framework.Assert.IsTrue(mue2.GetReplication() == 1);
                // ConcatDeleteOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(3, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Append);
                NUnit.Framework.Assert.IsTrue(((Event.AppendEvent)batch.GetEvents()[0]).GetPath()
                                              .Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[1].GetEventType() == Event.EventType
                                              .Unlink);
                Event.UnlinkEvent ue2 = (Event.UnlinkEvent)batch.GetEvents()[1];
                NUnit.Framework.Assert.IsTrue(ue2.GetPath().Equals("/file3"));
                NUnit.Framework.Assert.IsTrue(ue2.GetTimestamp() > 0);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[2].GetEventType() == Event.EventType
                                              .Close);
                Event.CloseEvent ce3 = (Event.CloseEvent)batch.GetEvents()[2];
                NUnit.Framework.Assert.IsTrue(ce3.GetPath().Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(ce3.GetTimestamp() > 0);
                // DeleteOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Unlink);
                Event.UnlinkEvent ue = (Event.UnlinkEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(ue.GetPath().Equals("/file2"));
                NUnit.Framework.Assert.IsTrue(ue.GetTimestamp() > 0);
                // MkdirOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Create);
                Event.CreateEvent ce4 = (Event.CreateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(ce4.GetiNodeType() == Event.CreateEvent.INodeType.Directory
                                              );
                NUnit.Framework.Assert.IsTrue(ce4.GetPath().Equals("/dir"));
                NUnit.Framework.Assert.IsTrue(ce4.GetCtime() > 0);
                NUnit.Framework.Assert.IsTrue(ce4.GetReplication() == 0);
                NUnit.Framework.Assert.IsTrue(ce4.GetSymlinkTarget() == null);
                // SetPermissionsOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue3 = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue3.GetPath().Equals("/dir"));
                NUnit.Framework.Assert.IsTrue(mue3.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Perms);
                NUnit.Framework.Assert.IsTrue(mue3.GetPerms().ToString().Contains("rw-rw-rw-"));
                // SetOwnerOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue4 = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue4.GetPath().Equals("/dir"));
                NUnit.Framework.Assert.IsTrue(mue4.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Owner);
                NUnit.Framework.Assert.IsTrue(mue4.GetOwnerName().Equals("username"));
                NUnit.Framework.Assert.IsTrue(mue4.GetGroupName().Equals("groupname"));
                // SymlinkOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Create);
                Event.CreateEvent ce5 = (Event.CreateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(ce5.GetiNodeType() == Event.CreateEvent.INodeType.Symlink
                                              );
                NUnit.Framework.Assert.IsTrue(ce5.GetPath().Equals("/dir2"));
                NUnit.Framework.Assert.IsTrue(ce5.GetCtime() > 0);
                NUnit.Framework.Assert.IsTrue(ce5.GetReplication() == 0);
                NUnit.Framework.Assert.IsTrue(ce5.GetSymlinkTarget().Equals("/dir"));
                // SetXAttrOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue5 = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue5.GetPath().Equals("/file5"));
                NUnit.Framework.Assert.IsTrue(mue5.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Xattrs);
                NUnit.Framework.Assert.IsTrue(mue5.GetxAttrs().Count == 1);
                NUnit.Framework.Assert.IsTrue(mue5.GetxAttrs()[0].GetName().Contains("field"));
                NUnit.Framework.Assert.IsTrue(!mue5.IsxAttrsRemoved());
                // RemoveXAttrOp
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue6 = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue6.GetPath().Equals("/file5"));
                NUnit.Framework.Assert.IsTrue(mue6.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Xattrs);
                NUnit.Framework.Assert.IsTrue(mue6.GetxAttrs().Count == 1);
                NUnit.Framework.Assert.IsTrue(mue6.GetxAttrs()[0].GetName().Contains("field"));
                NUnit.Framework.Assert.IsTrue(mue6.IsxAttrsRemoved());
                // SetAclOp (1)
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue7 = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue7.GetPath().Equals("/file5"));
                NUnit.Framework.Assert.IsTrue(mue7.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Acls);
                NUnit.Framework.Assert.IsTrue(mue7.GetAcls().Contains(AclEntry.ParseAclEntry("user::rwx"
                                                                                             , true)));
                // SetAclOp (2)
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Metadata);
                Event.MetadataUpdateEvent mue8 = (Event.MetadataUpdateEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(mue8.GetPath().Equals("/file5"));
                NUnit.Framework.Assert.IsTrue(mue8.GetMetadataType() == Event.MetadataUpdateEvent.MetadataType
                                              .Acls);
                NUnit.Framework.Assert.IsTrue(mue8.GetAcls() == null);
                // RenameOp (2)
                batch = WaitForNextEvents(eis);
                NUnit.Framework.Assert.AreEqual(1, batch.GetEvents().Length);
                txid = CheckTxid(batch, txid);
                NUnit.Framework.Assert.IsTrue(batch.GetEvents()[0].GetEventType() == Event.EventType
                                              .Rename);
                Event.RenameEvent re3 = (Event.RenameEvent)batch.GetEvents()[0];
                NUnit.Framework.Assert.IsTrue(re3.GetDstPath().Equals("/dir/file5"));
                NUnit.Framework.Assert.IsTrue(re3.GetSrcPath().Equals("/file5"));
                NUnit.Framework.Assert.IsTrue(re.GetTimestamp() > 0);
                // Returns null when there are no further events
                NUnit.Framework.Assert.IsTrue(eis.Poll() == null);
                // make sure the estimate hasn't changed since the above assertion
                // tells us that we are fully caught up to the current namesystem state
                // and we should not have been behind at all when eventsBehind was set
                // either, since there were few enough events that they should have all
                // been read to the client during the first poll() call
                NUnit.Framework.Assert.IsTrue(eis.GetTxidsBehindEstimate() == eventsBehind);
            }
            finally
            {
                cluster.Shutdown();
            }
        }