3.2.7 Operands related to system monitoring

9) 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 might 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: ~<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 configuration) is abnormally terminated. This is called the facility for monitoring abnormal process terminations. For details about this facility, see the HiRDB Version 9 System Operation Guide.
For a HiRDB single server configuration, abnormal terminations of single server processes are counted. For a HiRDB parallel server configuration, 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:~<unsigned integer>((10-3600)) (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
  • Do not use this operand in a system that does not allow abnormal termination.
  • 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 might increase, causing an adverse effect instead. Therefore, if you specify this operand, we recommend that you restart HiRDB in the system that terminated abnormally.
  • If a HiRDB server process terminates abnormally repeatedly, a large amount of troubleshooting information will be output, resulting in frequent input to and output from the HiRDB operating directory, possibly leading to a full disk.
Operand default
When this operand is omitted, the specification of the same operand in the system common definition is assumed. When the same operand is also omitted in the system common definition, the following values are assumed:
  • Maximum number of process abnormal terminations: 0
  • Monitoring interval: 600
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.YYN#1N#1
    pdcancel commandNN#2NN
    Internal forced termination (HiRDB internally issues SIGKILL and terminates a process)Y#3Y#3N#1N#1
    AbortYYYY
    One of the following:
    • Abnormal termination of server process by transaction recovery processing in an OLTP system
    Abnormal termination of server process by XDS transaction recovery processing#4
    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 might 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.
#4
If the completion status of a transaction executed from XDS on a server that provides the primary functionality cannot be determined, XDS transaction recovery processing might produce a rollback and the server process might terminate abnormally.