Disk cache incorrectly treated as out of date and not used to reload data due to un-synchronized system clocks

Disk cache incorrectly treated as out of date and not used to reload data due to un-synchronized system clocks

When the disk cache is enabled for Scheduled Updates, the disk cache may not be used for the reload of a report when the RAM cache is cleared despite the disk cache still being valid (per the last reload time, last scheduled refresh, and max cache age settings).

The worker host logs might show "normalized update time 01/01/0001 00:00:00" and ValidityStart=0 which means that the cached data is eligible for removal and will not be used for a report reload. For example:

INFO ;2017-06-14T21:06:49,406+00:00;2017-06-14 21:06:49,406;abcd2508-c66a-4ab2-870b-4111bc4d5bd1;12345678;WorkThread 181;SPOTFIRESYSTEM\scheduledupdates;Spotfire.Dxp.Web.Library.ScheduledUpdates;"Update of '/myFolder/myReport abcdad74-54d4-4e63-8f84-a0fbf877d0c7', execution time 00:07:09.7322750, normalized update time 01/01/0001 00:00:00 (JobDefinitionId=abcdc4f3-9654-4282-8635-35b38fc32ae6, JobInstanceId=abcd5d6f-7d8e-491d-bbf1-7afbf5d5d8fa)"

In some cases, when system clocks are not synchronized, the scheduled updates disk cache metadata may be incorrect and the cached data not used. To avoid issues with scheduled update and the disk cache, ensure the system times are synchronized across all Spotfire Servers and Node Managers. This can be done by enabling the Windows Time service (w32time) on all servers. Additionally, there was an improvement in the Web Player to help avoid this issue, even when the system clocks are not synchronized. To benefit from this, you can run the following versions of Spotfire:

• TS 7.6.1 HF-013 or higher
• TS 7.7.1 HF-004 or higher
• TS 7.8.0 HF-002 or higher
• TS 7.9 or higher

• https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/get-started/windows-time-service/windows-time-service