What O/S do you use for Development?

[Former Member]

There appears to be many issues with Windows XP as a development platform, not only for Netweaver, but for any application which requires a large amount of contiguous memory. I'm not prepared to recommend to our group that we use XP for development, due to the re-basing requirements of the various DLL's that fracture the memory address space, thereby preventing large-scale allocations of memory to the J2E engine. There are others reasons for not re-basing DLL's, namely the departure from company-installed code, issues with O/S updates, support issues, etc.

Linux, however, does not have these issues, as it properly handles memory.

Out of curiosity, what environments are people using for development? What O/S? Are you hosting a local J2EE?

Granted, if you're not hosting a local J2EE then these memory issues do not assert themselves, but I want the ability to run Netweaver locally without having performace suck. (ie: 1GB of memory or more allocated to the engine).

Comments?

[detlev_beutner · Accepted solution]

Hi Ken,

in our company, the developers and consultants have notebooks, now with 2 GB installed, running a local J2EE server with Enterprise Portal installed on top.

At the moment of writing these lines, the J2EE engine uses 336 MB, virtually 758 MB. This holds for WAS 6.20 J2EE and the values will be a bit higher for 6.40.

All these local notebook installations are running on XP. We have no serious trouble concering the chosen OS.

We have different central installations on our servers, based on 6.20 as well as on 6.40. Most of them are running within VMWare machines. We have different trouble with these, primarily memory issues.

Our worst installation is a RedHat Linux with VMWare GSX server with windows VMWares on top of it (and different 6.40 engines within these). The problems are that hard that it is quite probable that we will stop this combination soon (it is not quite clear if the main problems arise from RedHat or from VMWare, maybe a combination of both).

My personal experiences/thaughts are that the server itself is that "bombastic" that every additional complexity concerning the surrounding system should be avoided. I expect the J2EE server running more or less without (specific) problems on each OS, provided that you have someone at hand who is really familiar with this OS; VMWares are something I personally think which add to much failure possibilities to such a system.

Last remark: Only the SneakPreview of the J2EE engine (6.40) is supported to run on XP. The release versions are not. Within the next weeks, nevertheless I will try to make it run, don't know how hard the restrictions are.

Hope it helps

Detlev

[Former Member · Accepted solution]

Thanks Detlev, your answer was useful. However, I have a few other questions:

I'm very surpised at the memory allocation for your JVM - it seems very low. How much memory are you allocating to the JVM? I know that the XP installation I performed (as part of the DEVST installation) defaulted to 1GB for the AS. Accepting the defaults prevented the JVM from starting due to memory fragmentation issues (I also have 2gb of ram - gotta like XP's memory model). Without rebasing the offending DLLs, I had to reconfigure the JVM to request 512mb of mems to get it to start. Ugly.

How does the EP perform in these tight memory constraints? And, why are you running the EP locally? Is this just for testing your components in the EP? My understanding of the entire NW/EP environment is that the EP is really not required for development.

Lastly, how does licensing work wrt. the J2EE enginein 6.40? My understanding is that the licensing model has changed for NW 6.4 and EP 6, in that you only require a license for the J2E engine. If the only supported XP installation is the sneak peak release, and if it's only good for 120 days, what's a developer to do when the 120 days is up? Is SAP planning on a 'supported' release for XP for developers?

I certainly agree with keeping the host system as simple as possible - you seem to be working in a 'chinese boxes' type of environment, with multiple virtual layers complicating things. We'll certainly not be doing that.

Sorry for all the questions, but finding definitive answers to all my questions has been a difficult task.

Once again, thanks for the information.

Cheers!

-klm.

[detlev_beutner · Accepted solution]

Hi Ken,

> How much memory are you allocating to the JVM?

To be as precise as possible:

-Xms512M

-XX:SoftRefLRUPolicyMSPerMB=1

-XX:+DisableExplicitGC

-XX:MaxPermSize=192M

-XX:PermSize=192M

-XX:MaxNewSize=96M

-XX:NewSize=96M

-XX:SurvivorRatio=2

-XX:TargetSurvivorRatio=90

-Dmemory.manager=512M

-Xmx512M

...

Hope it helps. Think of it, it's for 6.20! 6.40 definitely consumes more memory.

The values from this morning, when I had started the server, didn't really change: Now it's 339MB, virtually 759MB.

> How does the EP perform

> in these tight memory constraints?

Quite good

> And, why are you running the EP locally?

> Is this just for testing your components in the EP?

Primarily for developing EP applications (what's my main profession).

> EP is really not required for development

... if you're not developing against the EP ...

> that you only require a license for the J2E engine

Almost. You'll have a central licence, but a portal specific one.

> what's a developer to do when the 120 days is up?

> Is SAP planning on a 'supported' release

> for XP for developers?

Good question, ask SAP As said, when I'll switch locally to EP6 NW04 (instead of SP2), I'll do my best to do so without switching the underlying OS...

Hope it helps

Detlev