ObSrv « Technical Musings

ObSrv Performance Improvements

I’ve improved the load speed of the ObSrv home page. Sometimes it would take a long time to load.

I’ve also improved the speed of the image feeds. It still can be sluggish at times – that’s because it’s heavily used, but to counteract this, the Image Feed will ignore requests from the same computer if they come more frequently than about once every 3 or 4 seconds.

For most people this won’t be a problem, and the only time you really notice delays on the Image Feed is if you try and display it in your browser.

If site performance is still an issue for you, please let me know.

Why only 21 images at a time?

Aaron asked a good question they other day.

Why does ObSrv only ever return 21 images at one time?

I thought it was a bug in my code, but it’s not. ObSrv pulls images from Google Image Search, and Google only ever returns 21 images in one go.

But this is not a problem. The images are embedded into a MediaRSS feed. That feed is cached for a maximum of one hour. After this time if you request the same feed, ObSrv will search again, but it will add in up to 21 extra images that weren’t shown last time. So on subsequent calls you’ll get more than 21 images in the feed. In the unlikely event that it runs out of images, it starts searching from the beginning again.

So although there’s nothing I can do about the 21 images at a time issue, it’s not a major problem because you will get more images after the feed refreshes – but remember, to save server resources (and to stop Google from banning me) it waits an hour between doing searches on the same terms.

Server Problems Fixed

I apologise for the unavailability of ObSrv.com over the last few days.

Our server failed, so we bought a new server, which also failed.

Not being one to give up easily, I’ve been on this issue since Friday lunchtime, and am relieved to say that as of about 10pm last night, everything is now working fine.

On the bright side, we have a larger, faster server so things should run much better than before.

Improved image search

I just fixed a couple of minor bugs which were preventing ObSrv from serving up images based on advanced google image searches.

They should be working ok now.

If you still have any problems, please let me know or reply to this post.

Getting an RSS feed from ANY site with images

I mentioned earlier that I’d modify ObSrv to be able to generate an RSS feed from any site that has images.

I didn’t realize it, but it already does this.

Just key in the search words, followed by site:yourdomain.com

For example, if you want a feed of all images of the planet Saturn from Nasa.gov, just type in:
Saturn site:nasa.gov

Or for a feed of all images of Antarctica from NationalGeographic.com, type in:
Antarctica site:nationalgeographic.com

How cool is that?

Some example image feeds

Here’s some slideshows built on image feeds from ObSrv. If you’ve got some you’d like to show the world, please send an email to mail {at] ObSrv [d0t} com and I’ll be happy to showcase it here for you.

Watching the World

I’ve just completed a project called “ObSrv” which will convert Google Image Searches into MediaRSS compliant RSS feeds.

If you don’t know what an RSS feed is, perhaps you should read this, or this. I love RSS because it’s an easy way to let other people know what you’re doing, and to find out news that is of specific interest to you. This blog (like almost all others) has an RSS feed. Most news sites and picture sharing sites have RSS too. This makes it easy for you to show their content on your website, or to view their content in an RSS reader.

If you don’t know what MediaRSS is, you might want to read the specification. Basically, it’s for a special type of RSS feed that contains media, such as pictures, video, and music. These feeds are cool because pictures, videos and music are much more entertaining than plain text. You can do more with them. For example, there’s a slideshow on the right hand side of this blog that updates every few seconds with pictures of hi-tech gizmos. It’s based on a Media RSS feed.

My favourite Media RSS application is John’s Background Switcher. It updates the wallpaper on your computer desktop with pictures from a Media RSS feed.

My only problem with Media RSS is that the biggest source of images on the web (Google Images) doesn’t serve up their image searches as an RSS feed. Which means that while you can search for images at google, you can’t automatically feed them into a media RSS application.

That’s where ObSrv comes in. It converts a Google Image search into a Media RSS feed.

Here’s how:

Go to http://obsrv.com/

Type a few search words in the box. (Hint. If you want, do an advanced search in Google Images, and copy the Google Images URL into the box instead).
Press ENTER or click on the “GO” button.