Wednesday, November 29, 2006
Posted on Wednesday, November 29, 2006 8:37:47 PM (Mountain Standard Time, UTC-07:00)  Comments [4] | 
Categories: ArcGIS Server | ArcSDE | ESRI

This week I'm attending the ESRI's System Architecture Design Strategies class, taught by Dave Peters. Last summer I posted about working with Dave at one of our client sites, and the class is a real transfer of his knowledge and experience in a very accessible form. If you are in charge of planning your GIS system design, be sure to get to this class.

Some interesting items from todays class:

I had never found the System Integration group's section of the ESRI web site, and they have a whole mess of performance test reports there - all kinds of intersting stuff like ArcGIS Server/ArcIMS performance on 64bit Windows Server, ArcIMS perfomance on Dual Core CPUs and a bunch of papers on high-availability solutions. Very cool if you are thinking about your technology platform.

We also discussed the 9.2 Server licensing situation.

First ArcSDE...
At 9.2 they have put a lot of work into addressing the "chatty" nature of the direct connect, so it's now supposed to be pretty close in performance to running ArcSDE on the server (giomgr.exe processes). So, that's nice. The upside of using direct connect is that you don't have to pay for an ArcSDE license for each socket on your DBMS box. So, this should be a cost savings since there is less load on your DBMS box (no giomgr.exe processes) - which means the same hardware can serve more users. And when you do scale up, there is no licensing hit to ESRI.

The downside is that for direct connect, everything must match in terms of version - so, your 9.2 clients must attach to a 9.2 database. Not bad, but service packs may also be linked - so if you patch the server, you'll need to patch all clients before they can connect again. So - while cheaper out of the gate, the admin complexity may make you think twice.

Which leads to a third option - running the ArcSDE service & giomgr.exe on a totally separate machine. [UPDATE 11/29: Apparently this has been an option for quite some time] Apparently this is a new option with 9.2, and although you have to pay for the sockets, it may be a better mix between SDE on the DBMS, or direct connect.



The ADF...
We also talked about the ADF, and as I noted, the current stance on the ADF is that the server it is deployed on must be licensed for all sockets.

I can't quote anyone on this, but apparently that there is quite a bit of room to negotiate with ESRI in regard to using the ADF to upgrade existing (particularly ArcIMS) applications.

That's it for today - tomorrow we're going to be talking about security & firewalls. This should be very interesting, as it will hilight some of the issues I see with having to have the web controls on the SOM/SOC box (or pay double)



Thursday, November 30, 2006 2:51:29 AM (Mountain Standard Time, UTC-07:00)
Hello Dave
just 2 questions:
1) from what you are writing, is it sure that direct connect is socket license free for reading data? I ask you this because switching from 8.3 to 9.0 I realized that they changed the policy: at 8.3 you needed a license only for writing data but not for reading, at 9.0 even for reading data you need the license, and you need to set ESRI_ARCSDE_LICENSE_FILE env variable
2) what you are telling about using same version of clients and servers (ArcGIS desktop 9.2 and ArcSde 9.2) is compassory only with direct connect or also using the ArcSDE services? At 9.0 also with the service you had to have aligned everything, and I didn't like that at all
3) About running the ArcSDE service & giomgr.exe on a totally separate machine: this option was already available for Oracle. Now is also available for SQL Server?
Thanks in advance
Paolo
Thursday, November 30, 2006 7:22:18 AM (Mountain Standard Time, UTC-07:00)
thanks Dave, good info. please report back what you find today, I'm sure it would be helpful to everyone.

some things I would like to know:
1) a true load test that uses both the AJAX and AGX clients hitting the 2D/3D caches. for me, this is the missing piece of the puzzle. with all of the extra http connections, I'm just not sure how many web servers (and now $$$ ADFs) are needed to handle a sustained group of concurrent users.

2) I was hoping that during the AGX beta, ESRI would release some of the metrics they found when setting up the base services (now ArcGIS Services). How many ADFs do they need? How many users did they plan on serving concurrently? The current streaming in AGX leaves a little to be desired but I know I've seen local versions that fly. Which leaves me only one conclusion, the servers are not scaled out enough to handle the load (potentially bad news for those looking to build their own AGX services in AGS). I really wish they would release what they have found so far...

3) If there will ever be a free (or cheap) version of the ADF that just serves 2D/3D caches. If this were available, you could reliably get your performance up to spec while still paying for real ADF used for tool creation.

cheers
brian
Thursday, November 30, 2006 7:32:35 AM (Mountain Standard Time, UTC-07:00)
Brian,

The 2D cache is just a set of folders with tile images, so it should be pretty easy to build a httphandler which could re-direct a WSTile (or whatever the proposed spec is called) request directly into the 2d cache. When my EDN disks arrive this is something I intend to try. This would allow the use of OpenLayers as a 2D client. From there it should be pretty easy to build out tools on both sides (in openlayers and AGS) which enable simple Identify type operations. In fact, this would be a really cool open source project...

As for the performance of clients using the caches vs AGS mapping services, the capacity planning tool has this as an option. We'll be going over this today, and I'm going to ask lots of questions (and see if I can post the outputs of the models)

Paolo: As long as you have an "enterprise" ArcGIS Server license at some level (Basic, Std, Adv), then you can use direct connect from the clients into a DBMS w/o paying per socket on the DBMS server. This is read-write, full geodatabase access.

Dave

Dave
Thursday, November 30, 2006 7:51:46 AM (Mountain Standard Time, UTC-07:00)
hey dave

2D cache - agreed, I was going to add that to the above post but decided to leave it off. so yes, an "OpenADF" that just serves map tiles is a great idea...

capacity planner - I've seen it and I'm not sure where you could check this. I'd be really interested to hear what Dave P. says about this.

cheers
brian
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