SAP HANA: Just a Sidecar to IBM i, For Now

March 4, 2014 Alex Woodie

It’s been about three years since SAP unveiled HANA to the world. And while the in-memory database platform currently only runs on X64 commodity hardware and not IBM‘s Power processor, SAP’s extensive IBM i customer base is starting to explore ways that HANA might fit into an SAP implementations running on Power Systems and IBM i.

Ron Schmerbauch, IBM’s technical lead for SAP on IBM i implementation, recently wrote about the possible integration options between IBM i and HANA. Currently, there are only two ways that HANA and IBM i can play together, Schmerbauch says: HANA as an analytical sidecar to a production SAP IBM i environment and using IBM i as an application server for a HANA database.

When using HANA as a sidecar, the HANA system takes over some of the reporting workload from DB2 for IBM i. This could be a good way to minimize the disruption to OLTP workloads that commonly occurs when the SAP ERP Central Component (ECC) overloads the production database with analytical SQL queries, he writes.

The sidecar option involves sending read-only copies of transactions from DB2 for i to HANA. “As rows are changed in the IBM i database tables that are being shadowed to HANA, the changes are sent to the copies so the HANA DB is just slightly behind real-time,” Schmerbauch writes. “If and when the particular reporting function is run, that small set of queries will go against the HANA database, leaving the IBM i to continue running OLTP functions without disruption.”

The second option is to use HANA as a database platform for certain SAP Business Warehouse (BW) or SAP Business Suite applications running on IBM i. The SAP applications still require a three-tier configuration with a separation between the database and the application server. But SAP customers could configure their systems to use HANA as the database server and IBM i as the application server.

While it’s possible to do this, there isn’t a great rationale at this point, Schmerbauch says. For starters, it would require moving all the data out of DB2 for i and into HANA and learning the new HANA-centric database administration, save/restore, and HA/DR skills.

And then there is the performance issue. Schmerbauch brings up the fact that no server vendors have ventured to run the SAP Sales and Distribution (SD) benchmark with HANA as the database layer. This, he says, “may be taken as a strong indicator that HANA’s OLTP performance is not competitive with row-based DB platforms” such as DB2.

In other words, an SAP-on-IBM i shop would have to be slightly unhinged if they wanted to use HANA as the database layer for their SAP applications. That leaves HANA as an analytic and reporting sidecar to a production IBM i system.

Schmerbauch brings up another alternative to even using HANA in the first place. (He is an IBM employee, after all, and doesn’t speak for SAP.) While HANA is good technology, big speedups can be had by simply loading up on memory and Flash/SSDs. IBM has also developed Encoded Vector Index (EVI) technology for DB2 for i, which enables faster columnar operations. However, SAP uses EVIs for building OLAP cubes in BW, so that advantage is already baked in. Then there’s DB2 BLU, but that’s currently an AIX-only offering that isn’t attractive to IBM i’ers.

There could be a third way to use HANA and SAP apps running on IBM i: Running HANA directly on Power. Last year, SAP executives said that they were exploring this with IBM and that it might happen. However, there hasn’t been any word from either IBM or SAP in the last 14 months about that possibility.

One could certainly make a case that the combination of HANA and Power could be a compelling alternative. One person who’s explored the possibility in considerable depth is Alfred Freudenberger, the head of sales for IBM Power Systems for SAP in North America. In his SAPonPower blog (which isn’t affiliated with his day job whatsoever), Freudenberger asks some compelling questions.

“Are you ready to bet your business on x86?” Freudenberger writes in his blog. “Do Intel systems offer the scalability that your business requires and can those systems react fast enough to changing business conditions? Are x86 systems reliable enough? Are x86 systems secure enough?”

What can SAP on IBM i users do about this? Freudenberger encourages them to let their SAP representatives know that “you are unwilling to take a chance on allowing your SAP Business Suite database systems to be placed on anything less than the most reliable, scalable, secure and flexible systems available, i.e. IBM Power Systems.”

Business Suite already runs very well on Power Systems, and until SAP is willing to support this platform for HANA, “there is very little compelling reason for you to consider a move to HANA.”