Comments on: Geoserver testing ..

By: GeoServer » Roadmap scorecard

GeoServer » Roadmap scorecard — Tue, 24 Apr 2007 23:19:23 +0000

[...] of the past few months have actually been made on the WFS side of the fence. Chris Tweedie has some information on his blog, the main work done is not so much on speed improvements, but on setting up a framework [...]

By: Chris Tweedie

Chris Tweedie — Sat, 21 Apr 2007 23:57:03 +0000

Andrea, did you mean try it out in Jetty? Those initial tests were using Tomcat5.5 ..

Give me a day and ill post something back to the list instead of continuing here

By: Andrea Aime

Andrea Aime — Sat, 21 Apr 2007 17:12:44 +0000

Soo, I made some tests of my own because the result above where fishy and… I could reproduce them, but only with the version we ship with the installer.

First try, version 1.5.0 installed from windows installer:
speed as reported by wget is the same, around 9-10MB/s, and yes, I made sure both PARTIAL-BUFFER, PARTIAL-BUFFER2 were both used making Geoserver log at FINE level.

Second try, 1.5.0 launched from my Eclipse (using an embedded launcher): PB 4MB/S, PB2 9-10MB/S. Hmmm….

Third try, the very same 1.5.0 copied inside a full blown Tomcat 5.5.20: PB 4MB/s, PB2 8-9MB/s. ???

Fourth try, 1.5.0 copied insied a full blown Jetty 6.0.1:
PB 9MB/s, PB2 9-10MB/s

Hey, what’s going on here? It seems Jetty 6.0.1 fully configured has a secret sauch that makes it faster than Tomcat, and faster than embedded one I use for testing inside Eclipse. What is it, I have no idea. Can you try out with Tomcat too and see if you replicate the same behaviour?

By: Chris Tweedie

Chris Tweedie — Sat, 21 Apr 2007 14:48:05 +0000

Cheers for the reply Andrea. I will give it a whirl on Monday on some local datastores and do another comparison. I’ll keep an eye on those patches

By: Andrea Aime

Andrea Aime — Sat, 21 Apr 2007 13:02:09 +0000

Hi Chris,
seeing your times I definitely think the SDE datastore it’s the bottleneck. To give you an idea, whilst I can extract 8MB/s GML from a shapefile, I can only do 4MB/s from Postgis (given the same data set, and dumping it fully to make spatial indexes contribution null).
In your example it seems the best case performance for GML is only 2MB/s. Now, there can be significant differences in the enviroment,
for example, in my case I’m on a desktop PC with two ide disks in raid 0, and postgis is sitting on the same machine as Geoserver. Putting a network in between would certainly make things quite a bit slower, because you have to consider network latency too.

That said, I have a set of patches sitting on my disk that would make GML encoding a lot faster (on my PC, the bottleneck when reading from Postgis is still turning numbers into strings using DecimalFormat), but if the datastore performance is sub par, that won’t help as much as in my local tests.

About shapefiles, heh, we have to create the files on a temp folder, zip them, and only after that we can stream them away. Worth investigating thought, it may be that the bottleneck is the shapefile creation (the only part I think I could optimize).