XCF_FDI
- Description:
- The Failure Detection Interval (FDI) is the amount of
time that a system can appear to be unresponsive before XCF will
take action to remove the system from the sysplex. Internally we
refer to this as the effective FDI, externally it is often designated
by the word INTERVAL (referring to the INTERVAL parameter in COUPLExx
and on the SETXCF COUPLE command).CHECK that the effective FDI
meets the following requirement:
SpinFDI <= EffectiveFDI <= MULT*SpinFDI + INC - Reason for check:
- It is recommended that the user let the system default the effective FDI to the SpinFDI by not specifying the INTERVAL keyword. The INTERVAL keword allows customers to specify an effective FDI that is larger than the Spin FDI. When specified, the INTERVAL value should be at least as large as the SpinFDI to give the system enough time to resolve a spin loop timeout before it gets removed from the sysplex but no so large that the rest of the sysplex suffers sympathy sickness. See message IXCH0510E for a detailed discussion of best practice for FDI.
- z/OS® releases the check applies to:
- z/OS V1R4 and later. Note, however, that the check has been updated for z/OS V1R11.
- Parameters accepted:
- MULT (must be an integer in the range of 1 to 9)
- INC (must be an integer in the range of 0 to 86400)
- User override of IBM values:
The following sample shows the defaults for customizable
values for this check. Use this sample to make permanent check
customizations in an HZSPRMxx parmlib member used at
IBM Health Checker for z/OS startup. If you just want a one-time
only update to the check defaults, omit the first line (ADDREPLACE POLICY)
and use the UPDATE statement on a MODIFY hzsproc command.
Note that using non-POLICY UPDATEs in HZSPRMxx can
lead to unexpected results and is therefore not recommended.
ADDREPLACE POLICY[(policyname)] [STATEMENT(name)]
UPDATE
CHECK(IBMXCF,XCF_FDI)
SEVERITY(MED) INTERVAL(004:00) DATE('date_of_the_change')
PARM('MULT(2),INC(5)')
REASON('Your reason for making the update.')- Reference:
- For more information, see z/OS MVS Setting Up a Sysplex.
- Messages:
- This check issues the following exception messages:
- IXCH0510E
- IXCH0206E
- SECLABEL recommended for MLS users:
- SYSLOW