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Preparing for Changes in 2007 Daylight Saving Time

March 5, 2007 by Nicki DuBose

This article describes the 2007 changes to Daylight Saving Time, how those changes will effect your Documentum installations, and how to mitigate the risks associated with the changes.

Introduction

I hope you aren’t an hour late to any of your meetings after March 11th. If you heed all the warnings, then you’ll get your calendar updated before the changes to Daylight Saving Time (DST) take place. If not, well, at least you are doing something about it now, right? Have you considered all of the applications that might be affected by the time change? If you’re not sure, keep reading and don’t let this sneak up on you in November.

The idea behind Daylight Saving Time is that with an extra hour of sun in the evening we have a decreased dependency on artificial light, resulting in lower energy consumption. In years past, Daylight Saving Time lasted from early April to the end of October. As part of the Energy Policy Act of 2005, the United States extended DST by four weeks from the second Sunday in March to the first Sunday in November, 2007. Congress will retain the right to revert DST back to the 2005 times once a study of energy consumption is completed. For most of the US and Canada, clocks “spring forward” from 1:59:59 a.m. to 3:00 a.m. local time on March 11th. In the fall, clocks “fall back” from 1:59:59 a.m. to 1:00 a.m. on November 4th.

Effects of DST Change

Software written prior to the Energy Policy Act of 2005 expects DST to start in early April. When DST starts in early March this year, these software applications are likely to be off by one hour for the three weeks between the new DST start time and the old start time. The same will hold true in November when the end time is extended by one week.

All operating systems, databases, and applications that process dates will be affected by the change to DST. With the extension to DST, many of these systems will be off by one hour for the additional four weeks of DST. This can impact applications that retrieve date and time data or compare the date and time values returned from operating systems or software applications. Applications will also be affected if they compare date and time values returned from a Java Virtual Machine.

For Documentum products, this means jobs (such as content publishing and time dependent workflows) will be off by an hour. Display times and scheduled events within the application may also be off by one hour. To prevent or resolve these issues, you will need to upgrade the Java Runtime Environment in each level of the Documentum product stack. This means that operating systems, databases, application servers and other time-sensitive software will require updates to mitigate the impact of the changes to DST.

Resolving the DST Issue

Depending on the particular application, you will typically have the option to upgrade your current platform to a newer version or to patch an existing version.

To resolve the issue for Documentum products, you will not only need to upgrade the Documentum products, but also the operating systems, databases, application servers and any other systems on which the products rely.

Operating System

The first step is to upgrade all non-DST compliant operating systems. For many of you, this will mean applying patches from Sun, IBM, Microsoft, HP, etc. On Windows, for example, you will need to download and execute the latest update for Windows from Microsoft. You should apply the upgrade to all machines with non-compliant operating systems.

Operating System DST Update Information
Microsoft Windows http://support.microsoft.com/gp/cp_dst
IBM AIX, Linux http://www.ibm.com/support/alerts/operatingsystem/us/
HP-UX http://www.hp.com/products1/unix/java/DST-US.html
Sun Solaris http://sunsolve.sun.com/search/document.do?assetkey=1-26-102178-1
RedHat Linux http://kbase.redhat.com/faq/FAQ_80_7909.shtm

Installed JRE

For Java based applications, vendors may refer to DST patches of the Java Virtual Machine (JVM), as well as the Java Runtime Environment (JRE). The JVM is the abstract, platform-independent engine used to execute Java byte code. The JRE, on the other hand, is the platform-specific implementation of the JVM plus some core libraries. While the date and time values are returned from the JVM, the JVM is often installed as part of the JRE.

Many applications install and use a separate Java Runtime Environment installation. The JRE stores rules about DST observation, so you will need to update JREs used by DST sensitive applications. It is recommended that you update the JRE on any machine hosting Documentum products. Below are links to various JRE vendors and their recommendations for patching or upgrading JREs.

Software Vendor DST Update Information
IBM http://www-306.ibm.com/software/webservers/appserv/runtimes/support/
HP http://www.hp.com/products1/unix/java/DST-US.html
Sun http://java.sun.com/developer/technicalArticles/Intl/USDST/

Database

Patching the database for DST compliance varies considerably for each of the database vendors. Use the links provided below to determine the appropriate action for your database and operating system combination.

DB Vendor DST Update Information
Oracle http://www.oracle.com/technology/pub/notes/daylight-saving-time-update-guide.html
SQL Server http://support.microsoft.com/default.aspx?kbid=931815
IBM DB2 http://www.ibm.com/support/alerts/software/us/#D
Sybase http://www.sybase.com/detail?id=1048699

Application Servers

You must also patch any application server instances used with Documentum. Use the links below to find the appropriate patch for your application server.

Application Server DST Update Information
IBM WebSphere Daylight Saving Time (DST) 2007 information for WebSphere Application Server
RedHat JBOSS DaylightSavingsTimeIssues
BEA WebLogic and JRocket 2007 Daylight Savings Time Changes

Documentum Products

Many Documentum products have an embedded JRE that must be patched as well. In the technical support note issued by Documentum was a list of product versions that require patches or upgrades for DST. If you are running one of the specified versions of the products listed in the following table, then you will need to download and run the JDK upgrade tool from Documentum. If you are running Documentum Content Management products version 5.3 Service Pack 3 on Solaris, Windows, or Linux, then your bundled JREs are already compatible.

The patching tool is available for transfer here.

Product Version Operating System(s)
Platform Server-Content Server (CS), Index Server 5.2.x, 5.3.x All
5.3 SP3 HP-UX, AIX
Documentum Site Caching Services 5.2.x, 5.3.x All
5.3 SP3 HP-UX, AIX
Documentum Desktop 5.2.x, 5.3.x Windows
Documentum Application Builder 5.3.x Windows
Documentum Application Installer 5.2.x, 5.3.x Windows
Documentum Content Intelligence Services (CIS) 5.2.5, 5.3.x Windows
Documentum API (DFC) 5.2.x, 5.3.x All
5.3 SP3 HP-UX, AIX
eRoom Enterprise Server 6.x, 7.x Windows
Documentum Forms Builder 5.2.x, 5.3.x All
5.3 SP3 HP-UX, AIX
Documentum Records Manager 5.2.5 SPx, 5.3 SP3 Windows
Documentum Business Process Manager (BPM) 5.2.x, 5.3.x Windows
Documentum File Share Services 5.2.x, 5.3.x Windows
Documentum FTP Services 5.2.x, 5.3.x All
5.3 SP3 HP-UX, AIX
Documentum Content Services for Woodwing 5.3.x All
5.3 SP3 HP-UX, AIX
Documentum Transformation products—DTS, ADTS, RPTS 5.3.x Windows
Documentum Media Transformation Services (MTS) 5.3.x Windows
Documentum Media Services 5.2.x Windows
Documentum Import Manager 5.2.x, 5.3.x Windows
Branch Office Caching Services (BOCS) 5.3.x All
5.3 SP3 HP-UX, AIX

Site Deployment Services

You may have noticed the technical alert regarding Daylight Saving Time issued by Documentum did not have any information about one of the Documentum products: Site Deployment Services (SDS). SDS is an OEM-product from Marimba that allows content to be replicated to multiple websites and databases. Like many other Documentum products, SDS contains an embedded JRE that you may need to upgrade. Because of the complexity of installing and configuring SDS, I would recommend that you only patch SDS if required by your particular installation.

So, how do you know if you need to upgrade SDS? SDS jobs are scheduled either ‘at’ a specific time and date or on a repeatable time interval, such as, every 30 minutes. If your configuration uses the “at” specifier, then you need to upgrade the embedded JRE. Marimba has only released the SDS patch for version 5.3.x. If you are running 5.2.x of SDS then you can only patch the embedded JRE at this time.

If you find other products missing from the technical alert, you should contact EMC Technical Support at http://powerlink.emc.com.

Final Thoughts

You may notice a few timestamps or other application activities are off by an hour and maybe you won’t. The truth is, depending on the time critical nature of your business, you may choose to do nothing about the DST changes. If you choose to patch or upgrade your existing applications, take the time to read all of the information and recommendations from your software vendors. For those of you who choose to ride it out, best of luck – and don’t forget to double-check your meeting times in November.

References

If you’d like more information on Daylight Saving Time, I’ve provided a short list of references for further reading.