[jira] [Created] (HBASE-14501) NPE in replication with TDE

["Enis Soztutar (JIRA)" <ji...@apache.org>]

Enis Soztutar created HBASE-14501:
-------------------------------------

             Summary: NPE in replication with TDE
                 Key: HBASE-14501
                 URL: https://issues.apache.org/jira/browse/HBASE-14501
             Project: HBase
          Issue Type: Bug
            Reporter: Enis Soztutar


We are seeing a NPE when replication (or in this case async wal replay for region replicas) is run on top of an HDFS cluster with TDE configured.

This is the stack trace:
{code}
java.lang.NullPointerException
        at org.apache.hadoop.hbase.CellUtil.matchingRow(CellUtil.java:370)
        at org.apache.hadoop.hbase.replication.regionserver.ReplicationSource.countDistinctRowKeys(ReplicationSource.java:649)
        at org.apache.hadoop.hbase.replication.regionserver.ReplicationSource.readAllEntriesToReplicateOrNextFile(ReplicationSource.java:450)
        at org.apache.hadoop.hbase.replication.regionserver.ReplicationSource.run(ReplicationSource.java:346)
{code}

This stack trace can only happen if WALEdit.getCells() returns an array containing null entries. I believe this happens due to {{KeyValueCodec.parseCell()}} uses {{KeyValueUtil.iscreate()}} which returns null in case of EOF at the beginning. However, the contract for the Decoder.parseCell() is not clear whether returning null is acceptable or not. The other Decoders (CompressedKvDecoder, CellCodec, etc) do not return null while KeyValueCodec does. 

BaseDecoder has this code: 
{code}
  public boolean advance() throws IOException {
    if (!this.hasNext) return this.hasNext;
    if (this.in.available() == 0) {
      this.hasNext = false;
      return this.hasNext;
    }
    try {
      this.current = parseCell();
    } catch (IOException ioEx) {
      rethrowEofException(ioEx);
    }
    return this.hasNext;
  }
{code}

which is not correct since it uses {{IS.available()}} not according to the javadoc: (https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#available()). DFSInputStream implements {{available()}} as the remaining bytes to read from the stream, so we do not see the issue there. {{CryptoInputStream.available()}} does a similar thing but see the issue. 

So two questions: 
 - What should be the interface for Decoder.parseCell()? Can it return null? 
 - How to properly fix  BaseDecoder.advance() to not rely on {{available()}} call. 



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