Results 1 to 4 of 4

Thread: onstat -g ses returns "Changing data structure forced command termination"

  1. #1
    Join Date
    Jan 2023
    Posts
    2

    onstat -g ses returns "Changing data structure forced command termination"

    Hello,

    I installed a new informix server version IBM Informix Dynamic Server Version 14.10.FC9 running on a RedHat Enterprise Linux 8.4 VM machine.
    I noticed that every time i run the command
    Code:
    onstat -g ses <sessionid>
    i receive the following message:
    Changing data structure forced command termination

    On informix log file i do not see any error or warning at the time that i execute the command.
    Note also that other commands eg.
    Code:
    onstat -g ath, onstat -g ckp, onstat -g dis
    , etc. are displaying the expected output.
    I only face this issue specifically with
    Code:
    onstat -g ses
    command.
    I found some old articles about this issue and they are mentioning a bug in informix if the client host which connects to the informix server has more than 8 characters in its hostname.
    I tested the above but the issue remains.
    Other suggestions mentioned that this output is displayed momentarily and if you try to run the command again the session information will be displayed but i tried to run the command repeatedly and i always get the same message.

    Is it a known bug on version 14.10? Is there any workaround or do i need to fix something in my onconfig file.
    If it is required i can post my onconfig file as well.

    Please advise.

  2. #2
    Join Date
    Jan 2023
    Posts
    2
    Quote Originally Posted by tuccero View Post
    Hello,

    I installed a new informix server version IBM Informix Dynamic Server Version 14.10.FC9 running on a RedHat Enterprise Linux 8.4 VM machine.
    I noticed that every time i run the command
    Code:
    onstat -g ses <sessionid>
    i receive the following message:
    Changing data structure forced command termination

    On informix log file i do not see any error or warning at the time that i execute the command.
    Note also that other commands eg.
    Code:
    onstat -g ath, onstat -g ckp, onstat -g dis
    , etc. are displaying the expected output.
    I only face this issue specifically with
    Code:
    onstat -g ses
    command.
    I found some old articles about this issue and they are mentioning a bug in informix if the client host which connects to the informix server has more than 8 characters in its hostname.
    I tested the above but the issue remains.
    Other suggestions mentioned that this output is displayed momentarily and if you try to run the command again the session information will be displayed but i tried to run the command repeatedly and i always get the same message.

    Is it a known bug on version 14.10? Is there any workaround or do i need to fix something in my onconfig file.
    If it is required i can post my onconfig file as well.

    Please advise.
    I was informed by IBM community group that this is a known bug on Informix version 11.40FC9.
    I am posting this here for anyone who might experience the same issue.

  3. #3
    Join Date
    Apr 2011
    Location
    Largo, FL.
    Posts
    78
    Thank You.

  4. #4
    Join Date
    Aug 2022
    Posts
    22
    The error message "Changing data structure forced command termination" is typically encountered when you are using the onstat command to view session information in an Informix database and there is a change in the data structure of the database while the command is running.

    This can happen if there is a concurrent DDL (Data Definition Language) statement being executed while the onstat command is running. DDL statements include commands such as ALTER, CREATE, and DROP, which can modify the structure of the database and cause the onstat command to terminate.

    To avoid this error, you can try running the onstat command at a time when there is less activity on the database or when no DDL statements are being executed.

    Another solution is to use the -U option, this will allow you to run onstat command even when there is a change in the database structure.

    onstat -g ses -U

    This will run the onstat command and will not interrupt even if there is a change in database structure.
    Please keep in mind that the performance of the onstat command might be impacted when using the -U option, so use it only if it is really needed.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •