Forum How do I...?

Increase Number of Outstanding HTTP requests

crieger
We have a report that generates about 320 dynamic requests to an http server to return back images. We were unsure if there was a limit on the number of http requests that can be made simultaneously in Prince.

When we loaded the image data upfront we had a report generation time of about 2 minutes. But now that we are making the http requests through the <img> tags the report generation time increased to about 7 minutes.

Is there any way to increase the speed on making the requests to get the images?
mikeday
We have a new feature in development that will allow Prince to make multiple concurrent HTTP requests, this should save a lot of time. It will be ready in a couple of weeks.

Another option is to use a caching HTTP proxy, and make Prince issue requests through that.
crieger
Thanks mike for the quick response again. You guys are great.

We will be excitedly awaiting your update for multiple concurrent http requests.
crieger
Hey mike just wanted to check up on this. Do we still have an expected release for multiple concurrent http requests?

Thanks,
Crieger
mikeday
Getting closer! :)
crieger
Has this been released yet?
mikeday
Not yet. Which operating system are you running Prince on, and 32-bit or 64-bit? Perhaps we can make a build now.
crieger
We are running a 64-bit version of Prince. Thanks we really appreciate that.
crieger
Oh sorry the OS is Ubuntu 12.04.3 LTS. Will be upgrading to 14.04.1 this week.
mikeday
Today we have uploaded Prince alpha packages for Ubuntu 14.04 that support parallel downloads. We will create packages for other platforms shortly.
crieger
Thank you. We will be trying to get it upgraded this week and will let you know how it goes. Is there any release notes we can get or is the parallel downloads the only thing that is current built into this alpha package?
mikeday
The roadmap has more info, no release notes yet. :)
mikeday
Prince 10 is now available, and includes support for parallel downloads. Release notes are available! :)
crieger
Most excellent Mike. Good job Prince team. Excited about the new release.
tobykemp
Excellent work Mike. I have been waiting for this.

I had a few questions about this new feature. Is it enabled by default? How many images are downloaded in parallel? Can I tune it?

Thanks again

Edited by tobykemp

mikeday
Yes, multiple parallel downloads are enabled by default, with 6 resources retrieved at a time. You can increase or decrease this with the --prefetch-threads option, or disable it entirely with --no-parallel-downloads.