hearbeat...

Wow, been a while since I last posted anything over here (not that I've been regular at posting somewhere else either). Guess, I've been a running a little out of steam lately when it comes to writing stuff. It's not like I don't have anything to share off-late, it's just that I don't have the energy to blog about it these days - & that pretty much sums up how the life is meandering along all this while. So this post is pretty much a beacon just to let people know that I am still alive!

Anyway, I've been working on couple of "different" stuff off-late. On our ASP.Net website we've be using the built in In-Proc Cache to cache our data-objects and when you have a pretty decent cluster size, you run into data-consistence issue apart from having to figure out how to purge caches which are not scattered all over your web-farm. I've been thinking of getting some centralized caching engine for a while and after giving MS Velocity (or whatever it's called now) & Memcached a trial, I've decided to go with memcached along with the enyim client library. We haven't rolled it out on production yet, but in our Dev environment things actually look quite good - no exceptions, good Cache-hit rates. I'll post the entire experience with memcached and integrating with asp.net in a separate blog.

The other thing that technically, I've been looking into is reverse-proxying our web servers. I compared both Squid & Varnish, and zeroed in on Varnish based on the online material available. We already have Varnish set-up before our solr-slaves (because it's quite easy to configure varnish to do that and you get about 40-50% reduction in response times) on production, and we haven't seen any issues with it. Our Varnish cache-hit rates have been actually quite low ~around 30%, which is something that we need to look at - cause to benefit from a reverse-proxy, you would want to have your cache-hits to be around 60-70% on an average. One drawback with Varnish is the documentation available on VCL (Varnish Configuration Language) but I guess if you are clear about your caching strategy, it's not that hard to write one.
Varnishing solr is actually a piece of cake (as you don't have to worry about anonymous v/s authenticated users, session cookies, persistent cookies etc) but when it comes to Varnishing your public web-servers, things can get quite tricky. I'll post in detail, the experiences & things that I learned while Varnishing our web front-ends in another post. By the way, we've been running Varnish before the IIS on our dev environment and things have been looking quite alright so far.
One last thing on the technical stuff - we've been monitoring the performances of our memcached & varnish using munin - more on this in some other post as usual. I know this is lot of Linux stuff for a .net shop but the fact is - I didn't find any good Windows alternative for the above stuff which was free and proved itself to be quite scalable.

Moving on - as some of you would know, photography has been a hobby & a stress-reliever for me. On the photography front - after quite a bit of contemplation I got myself the Cactus triggers so that I can move my Vivitar 285HV off-camera. Well, so far they have been working like a charm. The first shot that I tried; armed with my new off-camera flash capabilities was freezing the water splash - and after 54 shots in the darkness, I did get on keeper -

lemonade!

I'll post about the setup and how I went about this in another post. The other news on the photography front is that I did manage to sell on of my images on fotolia (no I am not a millionaire yet!).

Lastly, I have started playing the guitar again - it's been so many years since I last strummed so it's like I am learning anew!

Well, that pretty much sums up what I've been up to all this while, hopefully, I'll be a little bit more frequent with my posting habits.

Photography tidbits

One of the first thing that bites you if you're into photography is what subject to photograph? Do you just take pictures of the same ole' flowers, monuments or do you try to be different. The problem with trying to being different is finding out all those things which haven't been captured before. So, you hunt for those places/things (either mentally or physically) and then give up and in the end take the pictures of the same subjects which have been taken umpteen times before (butterfly on a flower, a flower petal, sunsets etc). You still believe that at least your photographs offer something different, maybe, a new perspective, a new *vision* (basically, all the things that you try to convince yourself with). Then, you get into some equipment acquisition syndrome and dream of owning the best in the class (read the most expensive); Zeiss & Leica lenses, Nikon D3X, Hasselblad: if something is so freaking expensive it gotta be good, right?

I am one of the 3 people in my country (the other two haven't been vociferous about it yet) who owns a 4/3rds system (a Olympus e-510), and honestly apart from a tiny-winy viewfinder; I haven't had too much to complain about the camera (I generally take all the blame for out of focus, horrifically shaky pics). Quite a few people have asked me why I invested into a 4/3rds system; well; just like my any other investment it wasn't something that I carefully thought about but was just an impulsive buy (I didn't even try it or any other brand before buying). It's a funny thing that I always believed I don't need a dSLR and was happy with my P&S (a Canon A95) till I decided to go for a trip to Corbett National Park where I had an opportunity to capture a tiger in the wild for the first time and boy, did I manage to capture it with a 3x optical zoom of Canon! I think sometimes you just need a better equipment to bail yourself out. Anyway, has the dSLR made me a better photographer than before? No, definitely not but it does allow me to experiment a bit more and push my own creative limits…it reminds me of a saying that I read long ago:

The difference between a picture and painting is that

a picture is a frozen captured moment of true life,

whereas a painting can be anything imagined in your mind.

..... someday, all these paintings will become pictures.

flickr & Popfly

I played a little with popfly to create a carousel stack of my images based on tag(s) from flickr, and well, had quite a few issues...firstly, the built in flickr block doesn't allow returning user images based on tag, so I ripped the flickr block and created mine. Had some issues with the block not allowing me to enter the flickr key for this block, so I hard-coded the key in the js file itself! The other thing is you can't pass querystrings to your mashup; so there is no way you can customize the mashup at runtime (well, in a way you can by using the user-input block; but that doesn't solve my problem). Anyway, creating the mashup was really straight-forward and given that popfly is in early alpha stages, I guess it will only get better.

Update 6/12: Played around with popfly a bit more and learnt quite a few things, which you might want to know:

• There is no way to pass querystring parameters to a mashup currently, this means that the mashup cannot be dynamic w.o. requiring user input: this will be implemented in next release.


• Some blocks like Carousel and Photo Sphere have rendering issues in fx and don't display at all on that browser: again something which will be fixed in next release


• You cannot really "rip" a block which requires a developer key and extend it, or more generically, you cannot create a block which requires a developer key unless you are willing to hard-code your key in the javascript itself.

Here's the link to the mashup.

Faces in Picasso's notebook

Most of the people who know me, know that I love photography. Once upon a time I had a use-n-throw camera, then a Pentax roll camera and now a Canon A95. Everyone asks me that if I love photography so much, why don't I get myself a DSLR and I always have one answer: I don't have a subject worthy enough a DSLR (...and when I had one, I coudn't afford the camera).

Yes Virginia, there is a Chesapeake