[HDDS-4477] Delete txnId in SCMMetadataStoreImpl may drop to 0 after SCM restart.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.1.0
• Component/s: SCM
• Labels: pull-request-available
• Assignee: Lokesh Jain
• Reporter: Glen Geng
• Created: 17/Nov/20 12:07
• Updated: 26/Jan/21 04:22
• Resolved: 25/Jan/21 13:24

Description

Summary

If SCM cleans up all the DeletedBlocksTransaction in deletedBlocksTable, then restart, the txID in SCMMetadataStoreImpl will drop to 0.

 

Detail

in SCMMetadataStoreImpl.java

public SCMMetadataStoreImpl(OzoneConfiguration config)
    throws IOException {
  this.configuration = config;
  start(this.configuration);
  this.txID = new AtomicLong(this.getLargestRecordedTXID());
}

private Long getLargestRecordedTXID() throws IOException {
  try (TableIterator<Long, ? extends KeyValue<Long, DeletedBlocksTransaction>>
      txIter = deletedBlocksTable.iterator()) {
    txIter.seekToLast();
    Long txid = txIter.key();
    if (txid != null) {
      return txid;
    }
  }
  return 0L;
}

 

in DeletedBlockLogImpl.java

public void commitTransactions(
    List<DeleteBlockTransactionResult> transactionResults, UUID dnID) {
  ...
  scmMetadataStore.getDeletedBlocksTXTable().delete(txID);
  ...
}

Issue Links

• links to: GitHub Pull Request #1828