[CALCITE-4489] Avatica JdbcMeta statement IDs Concurrency problem

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 1.17.0
• Fix Version/s: 1.18.0
• Component/s: avatica
• Assignee: Stamatis Zampetakis
• Reporter: Vlad Skarzhevskyy
• Created: 05/Feb/21 16:30
• Updated: 28/May/21 09:26
• Resolved: 11/Feb/21 15:35

Description

  We encountered the JdbcMeta statement IDs concurrency problems that lead to errors pulling the data from avatica JDBC remote http server under heavy load.
  The error stack trace for the error is  attached.
  
  Our setup:   Avatica JDBC remote  http server handled by Calcite on the server side.
  For the record we had not been able to reproduce the same problems with Avatica, only remote proxy connected directly to DB.
 
  We believe that  the cause of the problem is unsynchronized increment of connection.statementCount
  see  MetaImpl.createStatement
https://github.com/apache/calcite-avatica/blob/master/core/src/main/java/org/apache/calcite/avatica/MetaImpl.java#L213

public StatementHandle createStatement(ConnectionHandle ch) {
     return new StatementHandle(ch.id, connection.statementCount++, null);
}

 Suggested  fix is to use  AtomicInteger  for statementCount.
 Our stress tests show that the problem is resolved by the fix..
 
 

Issue Links

• relates to: CALCITE-906 Avatica JdbcMeta statement IDs are not unique
• relates to: CALCITE-636 Connection isolation for Avatica clients
• links to: Sugested changes github PR #137