DB2 11 Migration Preparation

As some plan their vacations this year, others are planning their DB2 11 migrations.  If you’re in the second category, begin by reading the DB2 migration documentation, and then look at the ten extra items below.  These ten items might just help you avoid any issues or problems.

1. Get on the latest cross-system IBM maintenance. IBM continues to test each DB2 release with the other IMS, CICS, WebSphere, and replication products.  DB2 11 with its many new features may impact many of these processing partners, so using the latest combination and tested software from IBM is usually the best solution to minimize issues.  This can be especially important for the replication products’ ability to handle the expanded LRSN in DB2 11.
   
   
2. Document your current performance.  Many of our mature DB2 environments already have standard DB2 performance reports.  It’s time to recheck them to make sure they capture the latest DB2 system memory allocations and performance figures from your most current application workload.  Also, communicate with the application analysts and programmers to make sure their software code base will be stable during the DB2 migration for both the Compatibility and New Function mode transitions.
   
   
3. Rebind packages.  The reason to Rebind is to get all the basic and extended DB2 10 version EXPLAIN information about your current applications.  Dynamic applications’ SQL information should be captured from your Dynamic Statement cache and EXPLAINed to document your current access paths.  This is always difficult, but because of lost source code, vendor software packages, and old interfaces, it’s important to document the EXPLAIN information of as many applications as possible.  This way, when DB2 11 is implemented, you can compare access paths and verify the improved performance in DB2 11.
   
   
4. Determine what needs to stay the same.  Are there any applications that need to be shielded from DB2 11?  If so check out the new DB2 APPLCOMPAT Bind parameter and shield your applications from any DB2 11 features appropriately.
   
   
5. Document current system memory usage.  Real storage requirements can increase up to 15 percent in DB2 11 depending on your system DSNZPARM definitions, workload profile, and overall settings, so be aware of your current DB2 10 configuration.  Make sure to take a reading of your current memory system usage and compare it to new storage requirements once your DB2 11 migration is complete.
   
   
6. Document APIs currently used.  Inventory all your DB2 Connect, JDBC, DRDA, and other interfaces.  Take the APIs list from your last DB2 migration or use your performance reports to get a list of all the current APIs and applications. Have a plan to test and verify these APIs, their operations, and before and after migration performance.
   
   
7. Verify your vendor products. Get on the DB2 11 compatible/verified DB2 11 endorsed releases of your vendor products.  This is especially important for any DB2 utilities to insure they are compatible and support DB2 11.  This also includes the IBM utilities.  Even though there are shops using IBM’s or other utilities with DB2 11 currently, every shop is a little bit unique.  Trust but verify.
   
   
8. Document current DSNZPARMs settings.  When DB2 10 came along, it had a large number of its mechanisms moved above the 2GB memory bar.  Some of these mechanism’s memory allocations are controlled by the DSNZPARM settings.  For some of the memory allocations, the default size of DB2 11 DSNZPARMs has been increased and needs to be reviewed.  This DB2 11 DSNZPARM default review is especially important for DB2 systems that are tight and/or work in memory-constrained environments.
   
   
9. Understand the existing APARs.  As with any software there are fixes (APARs) for DB2 11.  The good news is that the number of APARs in DB2 11 is dramatically down. It is only one tenth the number of APARs compared to DB2 10, and as compared to any previous release of DB2 because of the improved internal IBM and beta customer testing. Review the list of all the current DB2 11 APARS to see which ones might impact your DB2 systems and applications.
   
   
10. Get ready for expanded log records.   For most DB2 systems the workload, logging is manageable.  With the new expanded LRSN in DB2 11, the log records have gotten a bit bigger.  If your DB2 system is robust and fills the log space quickly, be prepared for the workload to fill up the log space even more rapidly.  Maybe this means defining more active logs or expanding to retain more logs over your recovery window.  Be prepared because the DB2 11 logs are going to take up more space and only your workload will dictate how much you’ll need.

These are only ten items and please share and pass along any additional ideas to help others as we migrate our systems to DB2 11 this year.

Dave Beulke is a system strategist, application architect, and performance expert specializing in Big Data, data warehouses, and high performance internet business solutions.  He is an IBM Gold Consultant, Information Champion, President of DAMA-NCR, former President of International DB2 User Group, and frequent speaker at national and international conferences.  His architectures, designs, and performance tuning techniques help organization better leverage their information assets, saving millions in processing costs.