There seems to be a strange behavior with maxscale when resetting a connection, after having a failed prepared statement.

#define check_mysql_rc(rc, mysql) \

do {\

  if (rc)\

  {\

    diag("Error (%d): %s (%d) in %s line %d", rc, mysql_error(mysql), \

         mysql_errno(mysql), __FILE__, __LINE__);\

    return(FAIL);\

  }\

} while(0)

  MYSQL_STMT *stmt= mysql_stmt_init(mysql);

  int rc;

  rc= mariadb_stmt_execute_direct(stmt, "SELECT 1 FROM nonexisting_table", -1);

  FAIL_IF(rc==0, "Expected error\n");

  rc = mysql_stmt_close(stmt);

  check_mysql_rc(rc, mysql);

  rc= mysql_reset_connection(mysql);

  check_mysql_rc(rc, mysql); => result in error

error is "Unknown prepared statement handler (4294967295) given to MaxScale (1243) "

4294967295 correspond to -1 => this is usually use by COM_STMT_EXECUTE to indicate to execute last prepared statement. mariadb_stmt_execute_direct might send a COM_STMT_CLOSE + COM_STMT_EXECUTE with id -1.

I don't understand what can cause this, because error occur on reset, but there is a strange behaviour with maxscale with this special "-1" feature.