Tuesday, July 24, 2007

Re-Sync With Compiz Fusion

With a few tips from the IRC guys and some general poking, I was able to get Compiz-Fusion to run concurrently with Beryl on the same server, to our thin clients. Now that they have "un-forked", I need to jump in and help test. I have about 20 people using Beryl, and they will continue to do so until I have had a chance to do some tuning and QA work on Fusion. Some new plugins have been added since my last build in April (ages ago in Internet time!) and they are very welcomed. Expo is very slick, and allows you to move applications between viewports via thumbnails.

[ Shot: 1680x1050 x 16bit color giving me around 100FPS over our network. 1440x900 x 16bit is giving about 120FPS ]

[ Shot: Spinning hexagon, cool new reflection plugin underneath. ]

Wednesday, July 18, 2007

Changing libgnomecups For Multiple Evolution Users

A quad processor server with 16GB of memory is able to run 200-300 Evolution sessions very easily. No tuning or changes are required to Linux or Evolution, it just works. However, one has to modify libgnomecups to scale over about 20 concurrent users. We are prepping a SLED server for deployment, and I had to make this change once again. I've made it twice before on various older versions of libgnomecups.

If you have over 20 concurrent Evolution users and people print their email (which they do!), cupsd gets hammered and consumes a lot of resources. It appears that if you print once from Evolution, you continue to always request status information from cupsd repeatedly until you close the current session. Cupsd is unable to keep up with the requests fast enough and what happens is that the Evolution composer window gets horribly unresponsive. The letters appear in the text widget at about 1/5 the speed of what you can type.

Before the patch, here is what cupds looks like with around 40 concurrent users. Notice cupds consuming CPU time. At the time of the shot, no print jobs were in the queue.

I make the following change to the code and recompile:

diff gnome-cups-printer.c.orig gnome-cups-printer.c
< #define UPDATE_TIMEOUT 5000 --- > #define UPDATE_TIMEOUT 500000

diff gnome-cups-queue.c.orig gnome-cups-queue.c
< #define UPDATE_TIMEOUT 3000 --- > #define UPDATE_TIMEOUT 300000

I then replace the stock libraries and reboot and today with identical user load, cupsd barely shows and the slow typing issue is fixed.

The server is now ready for 200-300 concurrent users. I'm not sure why Evolution keeps polling cupsd after a print job has been submitted. This change makes no apparent changes to the print process. libgnomecups should be altered in a manner that scales better, or at a minimum allow an environmental variable to be read. That would eliminate the requirement for a patch and recompile.

Friday, July 13, 2007

Install Going Well, Back To R&D

IT staff has been installing the new HP thin clients, and we haven't had any serious technical issues. Normally something happens during the install process that was completely missed, but I think our extensive beta period and testing resolved most of the issues beforehand. We are getting very positive feedback on the huge increase in performance. I guess going from 33Mhz to 1Ghz does that! :) It's my perception that the old thin clients will end up on E-bay, possibly in groups of 100. I'll alert everyone when they are available.

So with the thin clients moving out, I'm starting to work on some R&D again:

Evolution Printouts
Evolution really needs to have a plugin system for easily creating custom printouts. As I have mentioned in previous posts, printouts are the world to end users. A plugin system would allow end users to design and contribute xml files or something back to the project. Really all we would need is the ability to set column position, font, font size, fields, draw boxes, sort, assign colors and have a control-break. I have started to write my own custom printouts using ksh and the perl module PDF::CreateSimple to eliminate duplicate entry that was being done around the City. In this case I wanted to create a printout of all City employees, so I load them all into the Address Book view and then do a SelectAll and right-mouse and select "Saves as VCard...". All employees are then exported and placed into a single .vcf file. My ksh script then loops through and formats the information and creates a PDF file. I generate a regular listing, and wallet cards as seen in the shots below:

Sync With Fusion
I have about 20 users on Beryl with excellent results and today tried to sync with Fusion. Fusion is the future and I sure would love to help debug and test. However, compiz isn't running very well on ATI 9250s these days so I had to go back to Beryl. I entered a bug report. Something changed in Compiz after the Beryl fork, and I'll have to wait for patches. I'm on the IRC all the time as "dave_largo", if anyone wants me to try some fixes, hit me up anytime.