hbase0.96 put流程 源码分析

无意间多瞄了一眼hbase0.98的代码，想复习下put流程。发现htable里面已经找不到processBatchOfPuts（）奇怪了。看了半天原来变化还真大事实上0.96就没这个了，于是又搞了个0.96的代码看看

之前有篇能够对照差异，请转移至：http://blog.csdn.net/luyee2010/article/details/8435739 只是排版太乱将就看吧。
HTable.java

  public void put(final Put put)
      throws InterruptedIOException, RetriesExhaustedWithDetailsException {
    doPut(put);
    if (autoFlush) {
      flushCommits();
    }
  }
//批量
  @Override
  public void put(final List<Put> puts)
      throws InterruptedIOException, RetriesExhaustedWithDetailsException {
    for (Put put : puts) {
      doPut(put);
    }
    if (autoFlush) {
      flushCommits();
    }
  }

这里writeAsyncBuffer已经替换了原来的 writeBuffer，事实上仅仅是名字不同

  private void doPut(Put put) throws InterruptedIOException, RetriesExhaustedWithDetailsException {
    if (ap.hasError()){
      backgroundFlushCommits(true);
    }

    validatePut(put);

    currentWriteBufferSize += put.heapSize();
    writeAsyncBuffer.add(put);

    while (currentWriteBufferSize > writeBufferSize) {
      backgroundFlushCommits(false);
    }
  }

这里应该是backgroundFlushCommits与原来的flushCommits()差点儿相同,but跟踪进去，卧槽！，都是哪跟哪了，差异有点大。之前一行来着
connection.processBatchOfPuts(writeBuffer, tableName, pool);
1。假设当前writeAsyncBuffer不为空或者之前没运行无错误，提交writeAsyncBuffer

  private void backgroundFlushCommits(boolean synchronous) throws
      InterruptedIOException, RetriesExhaustedWithDetailsException {

    try {
      // If there is an error on the operations in progress, we don't add new operations.
      if (writeAsyncBuffer.size() > 0 && !ap.hasError()) {
        ap.submit(writeAsyncBuffer, true);
      }

      if (synchronous || ap.hasError()) {
        if (ap.hasError() && LOG.isDebugEnabled()) {
          LOG.debug(tableName + ": One or more of the operations have failed -" +
              " waiting for all operation in progress to finish (successfully or not)");
        }
        ap.waitUntilDone();
      }

      if (ap.hasError()) {
        if (!clearBufferOnFail) {
          // if clearBufferOnFailed is not set, we're supposed to keep the failed operation in the
          //  write buffer. This is a questionable feature kept here for backward compatibility
          writeAsyncBuffer.addAll(ap.getFailedOperations());
        }
        RetriesExhaustedWithDetailsException e = ap.getErrors();
        ap.clearErrors();
        throw e;
      }
    } finally {
      currentWriteBufferSize = 0;
      for (Row mut : writeAsyncBuffer) {
        if (mut instanceof Mutation) {
          currentWriteBufferSize += ((Mutation) mut).heapSize();
        }
      }
    }
  }

这个backgroundFlushCommits看了好久也没看出个啥来。仅仅好跟ap.submit(writeAsyncBuffer, true);
看到这个

Map<HRegionLocation, MultiAction<Row>> actionsByServer =new HashMap<HRegionLocation, MultiAction<Row>>();

的时候感觉一下子有希望了,这个应该跟之前的像吧！

  public void submit(List<? extends Row> rows, boolean atLeastOne) throws InterruptedIOException {
    if (rows.isEmpty()) {
      return;
    }

    // This looks like we are keying by region but HRegionLocation has a comparator that compares
    // on the server portion only (hostname + port) so this Map collects regions by server.
    Map<HRegionLocation, MultiAction<Row>> actionsByServer =
      new HashMap<HRegionLocation, MultiAction<Row>>();
    List<Action<Row>> retainedActions = new ArrayList<Action<Row>>(rows.size());

    do {
      // Wait until there is at least one slot for a new task.
      waitForMaximumCurrentTasks(maxTotalConcurrentTasks - 1);

      // Remember the previous decisions about regions or region servers we put in the
      //  final multi.
      Map<String, Boolean> regionIncluded = new HashMap<String, Boolean>();
      Map<ServerName, Boolean> serverIncluded = new HashMap<ServerName, Boolean>();

      int posInList = -1;
      Iterator<? extends Row> it = rows.iterator();
      while (it.hasNext()) {
        Row r = it.next();
        HRegionLocation loc = findDestLocation(r, 1, posInList);

        if (loc != null && canTakeOperation(loc, regionIncluded, serverIncluded)) {
          // loc is null if there is an error such as meta not available.
          Action<Row> action = new Action<Row>(r, ++posInList);
          retainedActions.add(action);
          addAction(loc, action, actionsByServer);
          it.remove();
        }
      }

    } while (retainedActions.isEmpty() && atLeastOne && !hasError());

    HConnectionManager.ServerErrorTracker errorsByServer = createServerErrorTracker();
    sendMultiAction(retainedActions, actionsByServer, 1, errorsByServer);
  }

定位row找到loc(HRegionLocation)

HRegionLocation loc = findDestLocation(r, 1, posInList);

按region聚合action:addAction(loc, action, actionsByServer);

//Group the actions per region server
private void addAction(HRegionLocation loc, Action<Row> action, Map<HRegionLocation,
  MultiAction<Row>> actionsByServer) {
final byte[] regionName = loc.getRegionInfo().getRegionName();
MultiAction<Row> multiAction = actionsByServer.get(loc);
if (multiAction == null) {
  multiAction = new MultiAction<Row>();
  actionsByServer.put(loc, multiAction);
}

multiAction.add(regionName, action);
}

然后是sendMultiAction（）

public void sendMultiAction(final List<Action<Row>> initialActions,
                              Map<HRegionLocation, MultiAction<Row>> actionsByServer,
                              final int numAttempt,
                              final HConnectionManager.ServerErrorTracker errorsByServer) {
    // Send the queries and add them to the inProgress list
    // This iteration is by server (the HRegionLocation comparator is by server portion only).
    for (Map.Entry<HRegionLocation, MultiAction<Row>> e : actionsByServer.entrySet()) {
      final HRegionLocation loc = e.getKey();
      final MultiAction<Row> multiAction = e.getValue();
      incTaskCounters(multiAction.getRegions(), loc.getServerName());
      Runnable runnable = Trace.wrap("AsyncProcess.sendMultiAction", new Runnable() {
        @Override
        public void run() {
          MultiResponse res;
          try {
            MultiServerCallable<Row> callable = createCallable(loc, multiAction);
            try {
              res = createCaller(callable).callWithoutRetries(callable);
            } catch (IOException e) {
              LOG.warn("Call to " + loc.getServerName() + " failed numAttempt=" + numAttempt +
                ", resubmitting all since not sure where we are at", e);
              resubmitAll(initialActions, multiAction, loc, numAttempt + 1, e, errorsByServer);
              return;
            }

            receiveMultiAction(initialActions, multiAction, loc, res, numAttempt, errorsByServer);
          } finally {
            decTaskCounters(multiAction.getRegions(), loc.getServerName());
          }
        }
      });

      try {
        this.pool.submit(runnable);
      } catch (RejectedExecutionException ree) {
        // This should never happen. But as the pool is provided by the end user, let's secure
        //  this a little.
        decTaskCounters(multiAction.getRegions(), loc.getServerName());
        LOG.warn("The task was rejected by the pool. This is unexpected." +
            " Server is " + loc.getServerName(), ree);
        // We're likely to fail again, but this will increment the attempt counter, so it will
        //  finish.
        resubmitAll(initialActions, multiAction, loc, numAttempt + 1, ree, errorsByServer);
      }
    }
  }

这里有几个都不是非常懂的样子
1。resubmitAll
2，receiveMultiAction
3，createCaller

直到后面在callable里的call方法里看到了responseProto = getStub().multi(controller, requestProto);这不是HRegionServer.multi()
先看callable吧,其它的慢慢再看。这个后面有 this.pool.submit(runnable)来提交运行的
callable创建

  protected MultiServerCallable<Row> createCallable(final HRegionLocation location,
      final MultiAction<Row> multi) {
    return new MultiServerCallable<Row>(hConnection, tableName, location, multi);
  }

call()方法

  public MultiResponse call() throws IOException {
    int countOfActions = this.multiAction.size();
    if (countOfActions <= 0) throw new DoNotRetryIOException("No Actions");
    MultiRequest.Builder multiRequestBuilder = MultiRequest.newBuilder();
    List<CellScannable> cells = null;
    // The multi object is a list of Actions by region.  Iterate by region.
    for (Map.Entry<byte[], List<Action<R>>> e: this.multiAction.actions.entrySet()) {
      final byte [] regionName = e.getKey();
      final List<Action<R>> actions = e.getValue();
      RegionAction.Builder regionActionBuilder;
      if (this.cellBlock) {
        // Presize.  Presume at least a KV per Action.  There are likely more.
        if (cells == null) cells = new ArrayList<CellScannable>(countOfActions);
        // Send data in cellblocks. The call to buildNoDataMultiRequest will skip RowMutations.
        // They have already been handled above. Guess at count of cells
        regionActionBuilder = RequestConverter.buildNoDataRegionAction(regionName, actions, cells);
      } else {
        regionActionBuilder = RequestConverter.buildRegionAction(regionName, actions);
      }
      multiRequestBuilder.addRegionAction(regionActionBuilder.build());
    }
    // Controller optionally carries cell data over the proxy/service boundary and also
    // optionally ferries cell response data back out again.
    PayloadCarryingRpcController controller = new PayloadCarryingRpcController(cells);
    controller.setPriority(getTableName());
    ClientProtos.MultiResponse responseProto;
    ClientProtos.MultiRequest requestProto = multiRequestBuilder.build();
    try {
      responseProto = getStub().multi(controller, requestProto);
    } catch (ServiceException e) {
      return createAllFailedResponse(requestProto, ProtobufUtil.getRemoteException(e));
    }
    return ResponseConverter.getResults(requestProto, responseProto, controller.cellScanner());
  }

这里主要看HRegionServer.multi（）

  public MultiResponse multi(final RpcController rpcc, final MultiRequest request)
  throws ServiceException {
    // rpc controller is how we bring in data via the back door;  it is unprotobuf'ed data.
    // It is also the conduit via which we pass back data.
    PayloadCarryingRpcController controller = (PayloadCarryingRpcController)rpcc;
    CellScanner cellScanner = controller != null? controller.cellScanner(): null;
    if (controller != null) controller.setCellScanner(null);
    List<CellScannable> cellsToReturn = null;
     MultiResponse.Builder responseBuilder = MultiResponse.newBuilder();

     for (RegionAction regionAction : request.getRegionActionList()) {
       this.requestCount.add(regionAction.getActionCount());
       RegionActionResult.Builder regionActionResultBuilder = RegionActionResult.newBuilder();
       HRegion region;
       try {
         region = getRegion(regionAction.getRegion());
       } catch (IOException e) {
         regionActionResultBuilder.setException(ResponseConverter.buildException(e));
         responseBuilder.addRegionActionResult(regionActionResultBuilder.build());
         continue;  // For this region it's a failure.
       }

       if (regionAction.hasAtomic() && regionAction.getAtomic()) {
         // How does this call happen?
  It may need some work to play well w/ the surroundings.
         // Need to return an item per Action along w/ Action index.  TODO.
         try {
           mutateRows(region, regionAction.getActionList(), cellScanner);
         } catch (IOException e) {
           // As it's atomic, we may expect it's a global failure.
           regionActionResultBuilder.setException(ResponseConverter.buildException(e));
         }
       } else {
         // doNonAtomicRegionMutation manages the exception internally
         cellsToReturn = doNonAtomicRegionMutation(region, regionAction, cellScanner,
             regionActionResultBuilder, cellsToReturn);
       }
       responseBuilder.addRegionActionResult(regionActionResultBuilder.build());
     }
     // Load the controller with the Cells to return.
     if (cellsToReturn != null && !cellsToReturn.isEmpty() && controller != null) {
       controller.setCellScanner(CellUtil.createCellScanner(cellsToReturn));
     }
     return responseBuilder.build();
   }

主要代码。其它都是build PB

 region = getRegion(regionAction.getRegion());
 mutateRows(region, regionAction.getActionList(), cellScanner);
  cellsToReturn = doNonAtomicRegionMutation(region, regionAction, cellScanner,
             regionActionResultBuilder, cellsToReturn);

当中mutateRows（）是PUT和DELETE相关的

  protected void mutateRows(final HRegion region, final List<ClientProtos.Action> actions,
      final CellScanner cellScanner)
  throws IOException {
    if (!region.getRegionInfo().isMetaTable()) {
      cacheFlusher.reclaimMemStoreMemory();
    }
    RowMutations rm = null;
    for (ClientProtos.Action action: actions) {
      if (action.hasGet()) {
        throw new DoNotRetryIOException("Atomic put and/or delete only, not a Get=" +
          action.getGet());
      }
      MutationType type = action.getMutation().getMutateType();
      if (rm == null) {
        rm = new RowMutations(action.getMutation().getRow().toByteArray());
      }
      switch (type) {
      case PUT:
        rm.add(ProtobufUtil.toPut(action.getMutation(), cellScanner));
        break;
      case DELETE:
        rm.add(ProtobufUtil.toDelete(action.getMutation(), cellScanner));
        break;
        default:
          throw new DoNotRetryIOException("Atomic put and/or delete only, not " + type.name());
      }
    }
    region.mutateRow(rm);
  }