Standing in the line for the return ferry tonight, along with hundreds of others who had been forced to try the ferry by the BART transbay outage, I had a chance to ask one of the SF Bay Ferry employees walking the line why they had not separated the Oakland & Alameda traffic with the extra boats they had added. That was something they had been doing when the free spare the air day rides increased the traffic. The answer was that they had not had time (or it simply didn’t occur to anybody to do it).
It reminded me though of the work we had done on our web services in the early days of scaling up to deal with rapid load increases. Sure, the first thing you do is add extra capacity. For the web service, more servers; for the ferry, more boats. That helps, but you might still find that some requests are hogging more of the resources than others, and delaying otherwise quick services.
Waiting in Alameda felt a bit like that yesterday morning as all the extra boats raced to Oakland & filled up, either arriving at Alameda with very little space for more people, or bypassing us completely because they were already full.
In our web world we faced a similar situation, with more complex requests holding up light weight requests that needed a fast response. The solution was simple: split the servers into two pools & manage the capacity for each pool separately. We actually ended up with more than two pools, but this simple approach has allowed us to manage resources much more efficiently and also implement automatic scaling for each pool independently. Sharding is often used for scaling databases, but it can also be effective for managing traffic.
The SF bay ferry service experienced a big spike in traffic today, and while they responded by adding additional capacity quickly (five boats instead of one this morning), they could have used that additional capacity more wisely and kept the lines at both Oakland and Alameda flowing more evenly.
Can’t believe it has been over a year since I’ve posted here. I actually started a post just over a year ago detailing the birth of my little boy. Then I decided that was too much information for public consumption & didn’t post it.
Now, over a year later, that little baby who seemed so fragile has become a toddler, running around our house getting in to everything he can reach. While my life is definitely still busier than it had been before his epic arrival, I think I can probably get back to posting here more frequently. Especially if I can get this Blogsy app for my iPad to work well – allowing me to write on BART.
You can probably expect a few reviews of baby products, as well as any commute horror stories (it is ironic that I am writing that today, the day of the big fire at West Oakland BART which caused havoc for my morning commute), but I’ll try to mix in some tech and photography posts too, promise.
I have uploaded some of my recent favourite photos to my Imagekind store. Included in the new uploads are a sea turtle and a sunset from Hawaii, the leafy sea dragon from the Monterey Bay Aquarium and a Catherine Wheel Pincushion that we recently added to our dining room wall (as a 16×20 canvas).
In addition to the Imagekind website, you can now browse and buy prints, framed or not, and canvases directly from your iPhone with the new Artview app.
With this black background and tiny specs reflecting the light, I think they look more like alien space craft than creatures from the deep.
Oh, and happy Earth Day as well. Got carried away with my aquarium photos and completely forgot to mention that I’ve started posting more articles to my Vertography Blog – a blog for all things green. Check it out, and add it to your RSS reader, if you’re still doing that, or follow @vertography on Twitter. I’ll see about a Facebook page soon as well.
For anybody who’s been down there, you’ll know just how hard it is to get a good shot of these guys. The room is dark, and people are pushing to get to the front and be right up close to the jellies. Oh, and did I mention that they’re constantly moving? Well, they are, not fast, but fast enough to make it that little bit harder to catch them well.
A little while back we took a Sunday drive down to the Monterey Bay Aquarium (one of my favourite places around here). This is one of the many photos I took while we walked around the aquarium – a shot of a leafy sea dragon. Aren’t they amazing!