Products
Webtrends Analytics 9.x
Webtrends Analytics 8.x
Issue
What impact does Daylight Saving Time have on Webtrends’ reports and scheduled jobs?
Resolution
When Daylight Saving Time begins, an hour of report data is lost between the previous hour and the starting hour, and when it ends, an hour of report data is added to the log files. The factors that affect time-related issues which occur as a result of Daylight Saving Time are the time on the web server/data collector, the time on the Webtrends server, and times specified in profiles. Additionally, the timestamp on Scheduled Jobs is affected by settings in both the Scheduler and for each user.
Note: The daylight saving time rules of the U.S. Energy Policy Act of 2005, effective March 11, 2007, have no impact on Webtrends and issues related to Daylight Saving Time other than the general implications mentioned below.
The following settings affect the timestamps displayed in reports. These settings may be useful for users viewing report data in regions other than where the Webtrends server is located, where Daylight Saving Time is not observed.
To use a custom time zone setting for all profiles, navigate to the following location in the user interface: Web Analysis > Options > Analysis > General. Specify Time Zone/DST Overrides.
Example:
A company based in the United States has operations in China, and a dedicated server has been set up for the Chinese division to use. The server is physically located in the United States but used exclusively by the Chinese division. Setting the time zone globally to GMT +08:00 will display report data in CST.
To specify a custom time zone setting on a per-profile basis go to: Web Analysis > Reports & Profiles > (edit the profile) > Analysis > General.
Example:
A company based in the United States has operations in China and a server physically located in the United States. A profile or sets of profiles have been allotted to and are used primarily by the Chinese division. Setting each profile to GMT +08:00 will display report data for only those profiles in CST.
The Time Zone setting for Scheduled Jobs displays the times for job execution and related status messages relative to the time zone specified. This applies to all users (unless overridden), and can be changed in the following area in the user interface: Scheduler > Options > Time Zone
This setting can be modified for individual users in the following location: Administration > Users > (edit user) > Preferences
These settings override the settings defined under the Scheduler on a per-user basis.
If Scheduled Jobs are running an hour off, review the Scheduler and user settings first.
More Information
Common issues related to Daylight Saving Time: “Reports show incorrect results over Daylight Saving weekend.”
This is due to the default setting within Microsoft Windows operating systems and other web servers that automatically set their clock back or forward one hour when Daylight Saving Time begins or ends. Log file data is collected from 01:00-01:59, after which the clock is set back to 01:00. Log file data collected in that next hour, which would have been from 02:00-02:59, is added to the 01:00-01:59 range. Because the data will appear out of sequence, the second hour will be discarded. When the server sets its clock forward one hour, the hour of 02:00 is skipped and reports will display what appears to be a gap in the data as a result of jumping from 01:59 to 03:00.
The following steps can be taken to preserve log data during this hour:
Set the web server to log data without the automatic adjustment to Daylight Saving Time: Go to Start > Settings > Control Panel > Date and Time > Time Zone
Uncheck the checkbox at the bottom for “Automatically adjust clock for daylight saving changes.”
The web server will continue logging data without omission.
“Scheduled events are running an hour off schedule since Daylight Saving Time began.”
When Daylight Saving Time changes occur the scheduled event triggers are not updated and will run either an hour behind or an hour ahead of schedule, depending on the time of year.
For installations running MS SQL, perform the following steps:
- Using Microsoft SQL Server Management Studio Express (a free download from Microsoft), connect to the Webtrends system database.
- Expand Databases > wt_sched > select Tables, right-click and select “New Query” to open the query pane.
- Choose one of the queries below –
To adjust the event to run an hour later, paste the following into the query pane and click the “Execute” button:
UPDATE dbo.WT_Schedule SET NextTrigger = NextTrigger + 3600;
UPDATE dbo.WT_Schedule SET StartTime = NextTrigger;
To adjust the event to run an hour earlier, paste the following into the query pane and click the “Execute” button:
UPDATE dbo.WT_Schedule SET NextTrigger = NextTrigger – 3600;
UPDATE dbo.WT_Schedule SET StartTime = NextTrigger; - Restart the “Webtrends – Scheduler Agent” service.
For installations running MySQL, perform the following steps:
- On the Webtrends server, open a command line window and navigate into the Webtrends installation folder and the path below: \common\database\mysql\bin
- Access the database by typing the following command:
mysql -u (username) -p [Enter]
password [Enter]
Note: The username and password are the MySQL credentials provided at the time of installation. Please contact Webtrends Technical Support if you are unable to access the system database. - Once logged in, at the MySQL prompt use one of the following commands:
To adjust the event to run an hour ahead type:
use wt_sched [Enter]
UPDATE WT_Schedule SET NextTrigger = NextTrigger + 3600; [Enter]
UPDATE WT_Schedule SET StartTime = NextTrigger; [Enter]
To adjust the event to run an hour later type:
use wt_sched [Enter]
UPDATE wt_schedule SET NextTrigger = NextTrigger – 3600; [Enter]
UPDATE wt_schedule SET StartTime = NextTrigger; [Enter]
exit [Enter] - Restart the “Webtrends – Scheduler Agent” service
Note: This will change all events within the database. If only a few of the events are running off schedule then the queries will need to be modified before execution. If this is the case, please contact Webtrends Technical Support for additional assistance with the query.