.-HOTIOTRM--=--0-------------------------. >>-+----------------------------------------+------------------>< '-HOTIOTRM--=--percentage_of_buffer_pool-'
| range: | 0 or 10–99 |
Specifies the percentage of the current size of the IO
buffer pool that a single session must have allocated to it to cause VTAM® to take corrective action.
Corrective action differs depending on the type of session involved:
- When the session type is SSCP-LU: deactivate the LU.
- When the session type is SSCP-PU: deactivate the PU.
- When the session type is LU-LU: terminate all sessions between the two logical units.
You can change the value of HOTIOTRM with the MODIFY VTAMOPTS
command while VTAM is running.
Note:
- It is very important that a proper expansion limit (XPANLIM) be specified on the IO buffer pool when HOTIOTRM is specified. An expansion limit allows VTAM to detect one or more hot sessions prior to complete CSA exhaustion. See the description of the IOBUF buffer pool for a complete description of the XPANLIM parameter.
- Investigate past VTAM console logs for VTAM IST930I messages when there did not seem to be a problem. Specifying HOTIOTRM greater than the percentages in these past IST930I messages will cause VTAM to not terminate sessions that "normally" use large amounts of the IO buffer pool. Usually, these session have not had proper session level pacing values specified. You might wish to consider specifying session pacing that will reduce the amount of IO buffers used by these sessions.
- If past console logs are not available, or no IST930I messages are found, specify a HOTIOTRM value of 50.