3.3.5 Operands related to system monitoring

11) pd_watch_time = SQL-maximum-execution-time
[Figure]<unsigned integer>((0-65535)) (seconds)
This operand is applicable to a HiRDB/Parallel Server.
Specifies a maximum execution time for SQL statements that are executed in a HiRDB server process.
If execution of an SQL is not completed within the specified amount of time, execution of that SQL is terminated.
Advantage
If the HiRDB server does not halt execution of an SQL statement, even though the HiRDB client has canceled SQL execution (by forcibly terminating a client process, for example), the HiRDB server may continue to execute the SQL statement and may lock resources for a long time. Specifying this operand places a limit on such a lock time.
Specification guidelines
Specify the largest value among the following time values:
Time specified by the PDCWAITTIME operand of the client environment definition
Time specified by the pd_lck_wait_timeout operand
Processing time of the SQL statement with the longest execution time
Notes
  • When 0 is specified for this operand, the SQL execution time is not monitored.
  • When 0 (no time monitoring) is specified for the PDCWAITTIME operand of the client environment definition for an SQL statement, the execution time of that SQL statement is not monitored.
  • When a value shorter than the SQL time is specified for this operand, processing may terminate during SQL execution, and an SQL error may be reported to the HiRDB client or abnormal termination may be reported to the HiRDB server.
  • For a HiRDB/Single Server, SQL maximum execution time is not monitored, even if this operand is specified. If this operand is specified, the specified value is used as the default value of the pd_lck_wait_timeout operand. Therefore, Hitachi recommends that you omit this operand for a HiRDB/Single Server.
12) pd_down_watch_proc = upper-limit-for-server-process-abnormal-terminations[,monitoring-interval]
This operand is used for monitoring the number of abnormal terminations of a HiRDB server process. Processes to be monitored are those that are abnormally terminated by PDCWAITTIME over or aborting.
If abnormal terminations of server processes occur frequently, new services may not be accepted. However, because server process abnormal termination does not cause HiRDB abnormal termination, HiRDB is in an online stopped state in effect. When this operand is specified, you can pull HiRDB out of this state by restarting it.
upper-limit-for-server-process-abnormal-termination: [Figure]<unsigned integer>((0-65535))
If abnormal terminations of server processes exceed the value specified in this operand, HiRDB (an applicable unit for a HiRDB/Parallel Server) is abnormally terminated. This is called the facility for monitoring abnormal process terminations. For details on this facility, see the HiRDB Version 8 System Operation Guide.
For a HiRDB/Single Server, abnormal terminations of single server processes are counted. For a HiRDB/Parallel Server, the total of the abnormal terminations in the front-end servers, back-end servers, and dictionary servers inside the unit is counted.
If 0 is specified, abnormal terminations of server processes are not monitored.
monitoring-interval:[Figure]<unsigned integer>((10-3600)) (units: seconds)
Specifies the interval (in seconds) for monitoring abnormal terminations of server processes.
For example, if 100 is specified, abnormal terminations of server processes are monitored every 100 seconds.
Advantages
  • Restart of HiRDB refreshes memory and resource statuses, improving the processing efficiency.
  • If abnormal termination of server processes occurs frequently, HiRDB is abnormally terminated, and thus the system can be switched over immediately.
Notes
  • When a server process is abnormally terminated, the KFPS01820-E message is output. Although this message is also output when the server process is abnormally terminated by the pdcancel command, this is not counted as an abnormal termination.
  • For a mutual system switchover configuration, multiple HiRDBs are activated on the same server machine when system switchover occurs. As a result, the system traffic may increase, causing an adverse effect instead. Therefore, if you specify this operand, Hitachi recommends that you restart HiRDB in the system that was abnormally terminated.
Operand rule
A monitoring interval cannot be specified alone. It must be specified with an upper limit for server process abnormal terminations.
Remarks
  • If HiRDB is abnormally terminated by the facility for monitoring abnormal process terminations, the KFPS01821-E and KFPS00729-E messages are output.
  • The following table shows the causes of server process abnormal termination and the server processes that are included in the abnormal termination count.
    Cause of server process abnormal terminationInclusion in abnormal termination count
    Single server processFront-end server processDictionary server processBack-end server process
    PDCWAITTIME operand value of the client environment definition has been exceeded.YYN1N1
    pdcancel commandNN2NN
    Internal forced termination (HiRDB internally issues SIGKILL and terminates a process)Y3Y3N1N1
    AbortYYYY
    Rollback has occurred in a UAP with XA connection.YYNN
    Abnormal termination of process other than those described hereYYYY
Legend:
Y: Included in abnormal termination count
N: Not included in abnormal termination count
1 If an error is detected in a transaction branch, the abnormal terminations of the front-end server process that have occurred in the same transaction branch are counted.
2 If the pdcancel command is used to forcibly terminate a back-end server process or dictionary server process, the front-end server process is internally and forcibly terminated. In this case, the abnormal termination of the front-end server process may be counted in some cases.
3 If an error is detected in a global transaction by an OLTP system, the abnormal terminations of the single server process or front-end server process that has occurred in the same global transaction are counted.