コード例 #1
0
  /**
   * Commits a temp block.
   *
   * @param sessionId the id of session
   * @param blockId the id of block
   * @return destination location to move the block
   * @throws BlockDoesNotExistException if block id can not be found in temporary blocks
   * @throws BlockAlreadyExistsException if block id already exists in committed blocks
   * @throws InvalidWorkerStateException if block id is not owned by session id
   * @throws IOException if I/O errors occur when deleting the block file
   */
  private BlockStoreLocation commitBlockInternal(long sessionId, long blockId)
      throws BlockAlreadyExistsException, InvalidWorkerStateException, BlockDoesNotExistException,
          IOException {
    long lockId = mLockManager.lockBlock(sessionId, blockId, BlockLockType.WRITE);
    try {
      // When committing TempBlockMeta, the final BlockMeta calculates the block size according to
      // the actual file size of this TempBlockMeta. Therefore, commitTempBlockMeta must happen
      // after moving actual block file to its committed path.
      BlockStoreLocation loc;
      String srcPath;
      String dstPath;
      TempBlockMeta tempBlockMeta;
      mMetadataReadLock.lock();
      try {
        checkTempBlockOwnedBySession(sessionId, blockId);
        tempBlockMeta = mMetaManager.getTempBlockMeta(blockId);
        srcPath = tempBlockMeta.getPath();
        dstPath = tempBlockMeta.getCommitPath();
        loc = tempBlockMeta.getBlockLocation();
      } finally {
        mMetadataReadLock.unlock();
      }

      // Heavy IO is guarded by block lock but not metadata lock. This may throw IOException.
      FileUtils.move(srcPath, dstPath);

      mMetadataWriteLock.lock();
      try {
        mMetaManager.commitTempBlockMeta(tempBlockMeta);
      } catch (BlockAlreadyExistsException e) {
        throw Throwables.propagate(e); // we shall never reach here
      } catch (BlockDoesNotExistException e) {
        throw Throwables.propagate(e); // we shall never reach here
      } catch (WorkerOutOfSpaceException e) {
        throw Throwables.propagate(e); // we shall never reach here
      } finally {
        mMetadataWriteLock.unlock();
      }
      return loc;
    } finally {
      mLockManager.unlockBlock(lockId);
    }
  }
コード例 #2
0
  /**
   * Moves a block to new location only if allocator finds available space in newLocation. This
   * method will not trigger any eviction. Returns {@link MoveBlockResult}.
   *
   * @param sessionId session Id
   * @param blockId block Id
   * @param oldLocation the source location of the block
   * @param newLocation new location to move this block
   * @return the resulting information about the move operation
   * @throws BlockDoesNotExistException if block is not found
   * @throws BlockAlreadyExistsException if a block with same Id already exists in new location
   * @throws InvalidWorkerStateException if the block to move is a temp block
   * @throws IOException if I/O errors occur when moving block file
   */
  private MoveBlockResult moveBlockInternal(
      long sessionId, long blockId, BlockStoreLocation oldLocation, BlockStoreLocation newLocation)
      throws BlockDoesNotExistException, BlockAlreadyExistsException, InvalidWorkerStateException,
          IOException {
    long lockId = mLockManager.lockBlock(sessionId, blockId, BlockLockType.WRITE);
    try {
      long blockSize;
      String srcFilePath;
      String dstFilePath;
      BlockMeta srcBlockMeta;
      BlockStoreLocation srcLocation;
      BlockStoreLocation dstLocation;

      mMetadataReadLock.lock();
      try {
        if (mMetaManager.hasTempBlockMeta(blockId)) {
          throw new InvalidWorkerStateException(ExceptionMessage.MOVE_UNCOMMITTED_BLOCK, blockId);
        }
        srcBlockMeta = mMetaManager.getBlockMeta(blockId);
        srcLocation = srcBlockMeta.getBlockLocation();
        srcFilePath = srcBlockMeta.getPath();
        blockSize = srcBlockMeta.getBlockSize();
      } finally {
        mMetadataReadLock.unlock();
      }

      if (!srcLocation.belongsTo(oldLocation)) {
        throw new BlockDoesNotExistException(
            ExceptionMessage.BLOCK_NOT_FOUND_AT_LOCATION, blockId, oldLocation);
      }
      TempBlockMeta dstTempBlock =
          createBlockMetaInternal(sessionId, blockId, newLocation, blockSize, false);
      if (dstTempBlock == null) {
        return new MoveBlockResult(false, blockSize, null, null);
      }

      // When `newLocation` is some specific location, the `newLocation` and the `dstLocation` are
      // just the same; while for `newLocation` with a wildcard significance, the `dstLocation`
      // is a specific one with specific tier and dir which belongs to newLocation.
      dstLocation = dstTempBlock.getBlockLocation();

      // When the dstLocation belongs to srcLocation, simply abort the tempBlockMeta just created
      // internally from the newLocation and return success with specific block location.
      if (dstLocation.belongsTo(srcLocation)) {
        mMetaManager.abortTempBlockMeta(dstTempBlock);
        return new MoveBlockResult(true, blockSize, srcLocation, dstLocation);
      }
      dstFilePath = dstTempBlock.getCommitPath();

      // Heavy IO is guarded by block lock but not metadata lock. This may throw IOException.
      FileUtils.move(srcFilePath, dstFilePath);

      mMetadataWriteLock.lock();
      try {
        // If this metadata update fails, we panic for now.
        // TODO(bin): Implement rollback scheme to recover from IO failures.
        mMetaManager.moveBlockMeta(srcBlockMeta, dstTempBlock);
      } catch (BlockAlreadyExistsException e) {
        throw Throwables.propagate(e); // we shall never reach here
      } catch (BlockDoesNotExistException e) {
        throw Throwables.propagate(e); // we shall never reach here
      } catch (WorkerOutOfSpaceException e) {
        // Only possible if session id gets cleaned between createBlockMetaInternal and
        // moveBlockMeta.
        throw Throwables.propagate(e);
      } finally {
        mMetadataWriteLock.unlock();
      }

      return new MoveBlockResult(true, blockSize, srcLocation, dstLocation);
    } finally {
      mLockManager.unlockBlock(lockId);
    }
  }