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First official SAP R/3 benchmarks on Linux
droesen writes "The Siemens SAP Competence Center did the first officially SAP-certified SAP R/3 benchmarks on Linux, using a Quad-XeonIII-Box. According to their press release (having some technical details) the result was the highest ever measured performance of SAP R/3 on quad-Intels. Interesting, because according to some voices, Linux doesn't scale well on SMP machines. "
The Linux kernel, like any multiprocessor OS, uses "locks" to protect critical sections of code which are not "thread safe". That is, for operations which will get messed up if another CPU starts monkeying with the same data structures, they put guards around any code that reads/writes those data structures.
:-)
In order to scale an OS kernel to a large number of processors, you need a larger number of locks accross smaller sections of code, so that there is less chance of contention over particular data structures. Solaris does this, which is one of the reasons it scales to 64 processors so well, but seems sluggish on a uniprocessor system. All those locks cary a significant amount of overhead.
Now, I imagine that we could define multiple "levels" of locks in the kernel. The higher the level, the more "fine grained" that lock is. If the locking functions are preprocessor macros, we could setup configuration flags that determine how fine-grained the kernel locks are.
For a single processor system, those macros simply disable/renable interrupts at lower levels, and are defined to by empty at higher levels. For a two or four CPU system, lower levels are spinlocks, but higher levels are empty, avoiding the overhead of a finely-threaded kernel. For a massively SMP machine (16+ processors), higher levels are empty and lower levels are spinlocks.
This would give you a finely-threaded kernel where the scalability wipes out the overhead of the locks on big machines, but does not impact performance on small machines.
No, I have no idea if this will work.
Comments, anyone?
dragonhawk@iname.microsoft.com
I do not like Microsoft. Remove them from my email address.
AFAIK the main problems with Linux in the Mindcraft studies lay in the networking part of the kernel. Applications like SAP don't really do that much of networking stuff, it's more reading and writing data to/from the database and doing calculations/sorting on that data. And, we all know 2.2 was made to do reasonably well on 4 processors. So to say I'm really, really surprised by this? No. Happy? Yes!
:-))) (implying that my boss see it the MS way, wanting to replace the nice RS6000's and other Unix machines with Netfinity's and NT :( )
;-)
I work for a company that is heavily involved in implementing/supporting/customizing another ERP product, Baan (you might have heard about it, Boeing uses it heavily, and had some problems with it). Baan is going the MS way, they want to sell mid-sized computers to mid/small-sized companies. Intel based, running on NT and MS-SQL, being the perfect solution. Just two weeks ago we had a visit from a MS marketing guy, telling us, of course, how beautiful the MS solution is, all integrated and all. When asked about Linux and if they see it as a real thread, he replied that Linux they watched Linux very closely, but that Linux hadn't proved itself with enterprise applications. For small businesses that's very important, they don't have the money to have a full-time Linux/Unix expert to support the box and think they *can* do the administration for the NT box themselves. Wrong? I do think so. The perfect solution I see is the remote administrated Linux box. The company I work for, or whatever other company, does your administration, from our office, or on-site if you want and you get to do what *you*'re good at. And now this news has hit the streets, that not only is Linux one of the most stable OS's, it also is really, really fast (faster than NT?), I think I'm going to dance a few rounds around my desk and drink a few virtual beers when I get home! There's hope for us all!!!
Oh yeah, FWIW, if you want Baan, on Intel, but don't like NT, ask Baan to give you the Linux version, they have it, just don't advertise it. Would they be afraid MS would cut funds if they'd advertise Linux?
Thimo
Avoid the Gates of Hell. Use Linux!
Okay, so how is this going to be refuted by Microsoft? Easy. SAP is a 3-tier architecture. You've got your clients, your application server (SAP R/3) and your database server (Oracle, Informix, DB2, MS SQL Server, etc.).
You can have as many application servers as you want, but you can only have one database (which could be comprised of multiple servers in a load-balancing cluster such as Digital UNIX's TruCluster on Alphas).
This Siemens test had both the application server and the database server on the same box. Not realistic. Not scalable. Not the way real companies use SAP.
Microsoft already has NT benchmarks with over 1,000 concurrent users. As long as your database server can handle it, you just stick 10 application servers (or however many you wish) out there to take the front end load, and boom - your results go up. In fact, I've seen some UNIX results with 40 application servers all hitting the same database.
Also, no companies are going to use this benchmark, since the database Siemens decided on was SAP DB. Years ago, SAP realized that they were too dependant on Oracle (they're the largest reseller of Oracle database servers). So, they set out to write their own database. Then they realized it's not that easy. No one bought it. I had heard that development of SAP DB was killed. Evidently not - it was just ported to Linux. Still, nobody uses it in the real world.
We're off to a great start here, but still have a long way to go. Still, thanks Siemens!
The Linux test score of 241 users appears to have made the top twenty on ideasinternational's 2-tier SAP benchmark list. (That appears to be the Linux/Siemens machine in 12th place.)
;)
Though still a long way from the leader, a Sun 10000 rated at 1410 users, it is closing in on machines like the 12-CPU IBM AS/400 at 330 users.
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