Complex migration with minimal downtime

After NRG Energy had acquired several other Energy providers in Texas as well as in the Northeast Home and Business segment, it was its goal to adequately support its growth and to achieve efficiency, effectiveness, and synergies. That is why NRG decided to transition its existing National Retail Platform (NRP) from Oracle database to Suite on HANA (SoH) database in their SAP ECC system to consolidate its customer operations into a single instance. NRG also needed to streamline its SAP ISU database, which had grown to almost 28TB following the various acquisitions and was impacting system performance across the business. The biggest challenge: achieve all of these goals while keeping downtime as low as possible.

Time was of the essence, as NRG’s most recent acquisition included a transition services agreement (TSA). This stipulated that the various handover activities – including IT carve-outs, administrative separations, and other transfers – were completed within a restricted timeframe. Also from a business perspective, the company understandably wanted to keep downtime to the absolute minimum
– less than a day – and avoid any impact on business continuity for 7.5 million customers.

Natuvion DCS: One tool, numerous possibilities

Intelligent transformation tools as project accelerator 

In order to resolve the issue with time constraints for the migration process, NRG Energy’s long-time consulting and solution provider, Utegration, referred NRG to Natuvion. Utegration is a Natuvion partner and knew about the Natuvion Data Conversion Server (DCS). Natuvion DCS was specifically designed to handle extremely large data volumes and can automate many typical transformation tasks. That makes it ideal for migration and transformation projects with tight time constraints as it was the case with NRG. Once NRG Energy became aware of the performance of Natuvion DCS, it approved an 18-hour downtime window for Natuvion to complete the analysis and migration. 

Near Zero Downtime project approach 

The project involved moving all of NRG Energy‘s master and transactional data from Oracle database to Suite on HANA database in their SAP ECC system and included Unicode conversion on the fly. 

Natuvion structured the NRG Energy project with Natuvion DCS project by using the SAP Database Migration Option (DMO) in uptime followed by the Natuvion DCS Near Zero Downtime (NZDT) approach in downtime. To achieve NZDT, Natuvion DCS applies procedures such as data synchronization (triggers), the identification of warm or cold data, and waving mechanisms. The combination of these features with Natuvion DCS’ high level of automation enabled NRG Energy to eliminate the need for time-consuming manual work. 

NZDT: Data Migration - Any DB to Any DB 

Step by step to a smooth migration 

First, Natuvion made a 100% copy of the Oracle source database, containing all of the master and transactional data, and migrated this copy into an empty HANA shell (the target). In addition, the Natuvion team utilized a tool available within Natuvion DCS that counts all of the table entries. This check confirmed that the tables contained the same amount of data on both the source and target systems. 

The second phase included all of the activities from the first step plus a test of the NZDT approach.

In the following dress rehearsal Natuvion ran the uptime migration from the Oracle source to the HANA target. This involved system downtime of just two hours but ran for about two weeks while maintaining uptime. Once the uptime migration was finished and validated, the triggers were disabled and changes that had occurred during the previous two weeks were migrated into the Suite on HANA system.

That’s when it was time for the go-live. The Natuvion team’s idea was to turn off the archiving process during cutover – and this initiative reduced the delta migration downtime from 18 hours to 13 hours. The reason: During the dress rehearsal, the Natuvion DCS triggers detected 3.8 billion changes. After deactivating archiving during cutover, the triggers captured 1.7 billion changes, which was 46% fewer records to migrate.

Once the migration was complete, the Natuvion team also provided NRG Energy with three weeks of follow-up customer care. 

Successful migration with only 13-hour downtime

Natuvion’s approach was to do a 100% data migration with near-zero downtime using its trigger methodology. This ensured that 100% of the data could be migrated with only a 13-hour downtime.

“The major benefits for us were the exceptionally fast migration time and especially the reduction in database size,” comments Kalim Tippitt, IT Senior Director at NRG Energy. “We started with an unwieldy 28TB database and ended up with a streamlined 4.21TB database in SAP HANA.”

Knowledge transfer was another important part of the project as NRG Energy staff were actively involved in every phase of the project. They participated in the weekly tracking meeting to coordinate next steps, identified any blockages, raised any issues and potential risks, as well as taking all the necessary actions to keep the project on track. This helped ensure that the unit test, system test, performance test, IT test and business test all ran smoothly on a well-coordinated testing plan.

Crucially, Natuvion finished the delta migration even faster than the 18 hours estimated for cutover, completing it 5 hours earlier than expected.

Kalim Tippitt confirms his and the company’s satisfaction with Natuvion’s work and use of its innovative tools. “The proposed 18-hour downtime was already very ambitious and we were really impressed that Natuvion achieved the migration even faster than planned. The migration and smaller database will definitely help our business performance while supporting our growth and M&A plans going forward.”