max_time_diff - Maximum time difference between members configuration parameter
This parameter specifies the maximum time difference that is permitted between members listed in the node configuration file. This parameter can be used in a DPF environment as well as a Db2® pureScale® environment.
- Configuration type
- Database manager
- Applies to
- Members with local and remote clients
- Parameter type
- Configurable
- Default [range]
- In Db2 pureScale environments
- 1 [1 - 1 440]
- Outside of Db2 pureScale environments
- 60 [1 - 1 440]
- Unit of measure
- Minutes
Each member has its own system clock. The time difference between two or more member system clocks is checked periodically. If the time difference between the system clocks is more than the amount specified by the max_time_diff parameter, warnings are logged in the db2diag log files.
In a Db2 pureScale environment, to ensure that members do not drift out of sync with each other, a Network Time Protocol (NTP) setup is required and periodically verified on each member. If chronyd or ntpd is not detected, warnings are logged in the db2diag log files.
The SQL1473N error message is returned in partitioned database environments where the system clock is compared to the virtual time stamp (VTS) saved in the SQLOGCTL.LFH log control file. If the time stamp in the .LFH log control file is less than the system time, the time in the database log is set to the VTS until the system clock matches the VTS.
Db2 database manager uses Coordinated Universal Time (UTC), so different time zones are not a consideration when you set the max_time_diff parameter. UTC is the same as Greenwich Mean Time.