apache/hadoop · error · IllegalStateException

Cannot create Data Block after Meta Blocks.

Error message

Cannot create Data Block after Meta Blocks.

What it means

Error "Cannot create Data Block after Meta Blocks." thrown in apache/hadoop.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/file/tfile/BCFile.java:427

    }

    /**
     * Create a Data Block and obtain an output stream for adding data into the
     * block. There can only be one BlockAppender stream active at any time.
     * Data Blocks may not be created after the first Meta Blocks. The caller
     * must call BlockAppender.close() to conclude the block creation.
     * 
     * @return The BlockAppender stream
     * @throws IOException
     */
    public BlockAppender prepareDataBlock() throws IOException {
      if (blkInProgress == true) {
        throw new IllegalStateException(
            "Cannot create Data Block until previous block is closed.");
      }

      if (metaBlkSeen == true) {
        throw new IllegalStateException(
            "Cannot create Data Block after Meta Blocks.");
      }

      DataBlockRegister dbr = new DataBlockRegister();

      WBlockState wbs =
          new WBlockState(getDefaultCompressionAlgorithm(), out,
              fsOutputBuffer, conf);
      BlockAppender ba = new BlockAppender(dbr, wbs);
      blkInProgress = true;
      return ba;
    }

    /**
     * Callback to make sure a meta block is added to the internal list when its
     * stream is closed.
     */
    private class MetaBlockRegister implements BlockRegister {

View on GitHub (pinned to 2add963021)

Solutions

1. Write all data blocks before any meta blocks; BCFile requires data blocks first, meta blocks after.

When it happens

Trigger: Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/file/tfile/BCFile.java:427 when the library encounters an invalid state.

Common situations: Occurs when a Data Block is created after Meta Blocks have been written. Write all data blocks before any meta blocks in a BCFile.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/63bfcd90ea7465c2. Report an issue: GitHub.