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QCAD Pro Server on Amazon Web Services (AWS)

Posted: Thu Apr 04, 2019 6:22 pm
by DougVW
Software: QCAD Pro Server 3.22.0 on CentOS 7

I wanted to check if any of you have had experience hosting QCAD on AWS? If so, what machine parameters are key?

Have been using QCAD+dwg2pdf on an old Dell Optiplex Pentium server on our internal network and it has worked reliably and fast enough with great quality output. More recently we have been testing deployment of this service on an AWS virtual machine. It works sometimes, but mostly unreliably. It seems to hang on disk I/O. We've tested various disk volume types and different machine classes, yet have not found a working server for QCAD on AWS.

I don't believe this is a QCAD problem, as I can't replicate the hangups on any non-AWS machines. I've tested up to 40MB DXF input to 10-page 2.2MB PDF output which might take 3 minutes on an old box, but it works reliably on non-AWS machines.

I don't have non-proprietary sample files to share at this time, yet here are some typical file stats:
DXF input: 4.7MB
PDF output: 1.5MB (3 pages)
Maximum disk I/O seen: about 100K/S
Time to convert: 10-15s on an i7 test box, 20-25s on an old Pentium, 25s on AWS if it doesn't hang.

Thanks for any suggestions or links to some large multi-sheet public DWG/DXF you might have.


Re: QCAD Pro Server on Amazon Web Services (AWS)

Posted: Fri Apr 05, 2019 10:01 am
by andrew
Not my area of expertise to be honest.. I'd start by monitoring the AWS memory usage and CPU usage. I can imagine that processes are shut down when certain conditions are met.

Re: QCAD Pro Server on Amazon Web Services (AWS)

Posted: Fri Apr 12, 2019 4:07 pm
by DougVW
Just for the record, we got this working this week. As suspected, it was not a QCAD problem, and required advanced configuration of the machine parameters including swap space. Here's a couple of links in case anyone else has to deal with similar issues. ... ce-freezes ... oting.html

Re: QCAD Pro Server on Amazon Web Services (AWS)

Posted: Fri Apr 12, 2019 4:19 pm
by andrew
Excellent, thanks for the update and the links.