[HIVE-20888] TxnHandler: sort() called on immutable lists

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0-alpha-1
• Component/s: Transactions
• Release Note: n/a
• Assignee: Igor Kryvenko
• Reporter: Gopal Vijayaraghavan
• Created: 08/Nov/18 04:12
• Updated: 17/Nov/22 08:54
• Resolved: 15/Nov/18 00:43

Description

        } else {
          assert (!rqst.isSetSrcTxnToWriteIdList());
          assert (rqst.isSetTxnIds());
          txnIds = rqst.getTxnIds();
        }

        Collections.sort(txnIds); //easier to read logs and for assumption done in replication flow

when the input comes from

  @Override
  public long allocateTableWriteId(long txnId, String dbName, String tableName) throws TException {
    return allocateTableWriteIdsBatch(Collections.singletonList(txnId), dbName, tableName).get(0).getWriteId();
  }

java.lang.UnsupportedOperationException: null
    at java.util.AbstractList.set(AbstractList.java:132) ~[?:1.8.0]
    at java.util.AbstractList$ListItr.set(AbstractList.java:426) ~[?:1.8.0]
    at java.util.Collections.sort(Collections.java:170) ~[?:1.8.0]
    at org.apache.hadoop.hive.metastore.txn.TxnHandler.allocateTableWriteIds(TxnHandler.java:1523) ~[hive-standalone-metastore-server-4.0.0-SNAPSHOT.jar:4.0.0-SNAPSHOT]
    at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.allocate_table_write_ids(HiveMetaStore.java:7349) ~[hive-standalone-metastore-server-4.0.0-SNAPSHOT.jar:4.0.0-SNAPSHOT]