Saturday, October 22, 2011
Eric Roch, chief technologist of Perficient posted a question about the use of event processing for message routing rather than ESB, the router pattern is taken from the enterprise integration patterns by Gregor Hohpe and Bobby Woolf that we cite several times in the EPIA book. Roch mentions several reasons to use event processing, some of it relates to non-functional characteristics such as low latency, and in-memory management.
I think that there is some continuum that relates to the routing requirements - some of the routing decisions are quite simple, they are based on a predicate, typically on a value of a single attribute; some are more complex, and the routing is determined according to a pattern that involves multiple messages, in other cases the routing decision might involved a structure like decision-tree or decision-table, yet in other cases the routing is determined according to probabilistic reasons.
The better solution is not to have ESB and EP systems in isolation, and chose in each case what should be used, instead it is better to use a single programming model that includes all types of routing, and autonomic translation to implementation in various building blocks, some of them are taken from event processing and some from ESB or traditional messaging systems, this is the approach I prefer for event processing in general, not stand-alone, but synergistic with other technologies. In 2008 I had a posting about event processing and ESB, arguing that ESB is a natural carrier of event processing within a SOA architecture, and indeed I think that we'll see more and more ESB products that are enriched by event processing capabilities.
Thursday, October 20, 2011
Pura vida - means "pure life", is an expression that is being used in Costa Rica as: good morning, hello, response to the question "what's up?", general statement that life is good, thank you - and some others. It is the motto behind life in Costa Rica. We spent in Costa Rica 10 days (1 less than we planned), and here are some impressions:
- Costa Rica is an excellent place for a trip in the nature - it has nice rain forests, rivers and volcanoes, as well beaches of the two oceans.
- Animals -- you see them everywhere in nature. There are various tours in foot, car and boat to see animals.
- The Parador hotel we stayed in the last 3 days of the trip is the best hotel I've ever been to (and I traveled all over the world). The picture above is the view from the hotel room, it was elected several times as best hotel in central america (including Mexico), and best spa (I got there the best massage since my visit in Thailand in 2007), t it is located within a forest on a mountain overlooking the pacific ocean in Manual Antonio, it has various animals on site - a hawler monkey provided wake-up call in one of the days in 5am, with extremely loud voice, on the tree in front of the hotel room; a raccoon entered the daughters' room, when they did not close the balcony's door, and scared them a bit, other raccoons visited us at the dinner table, and were scared away by the hotel staff. An iguana caught some sun in the middle of the mini-golf course, and frogs have settled at night in the swimming pool.
- The local people in Costa Rica eat the same food - breakfast, lunch, dinner -- rice and beans and tropical fruits (in each they might have some supplements). At the end we got tired from this food and escaped to the sushi menu at the Parador.
- Rain -- Costa Rica has a lot of rain, especially in this season. It has a four day heavy rain storm at the pacific side, we had there in the last two of these in Monteverde, but we did most activities in the rain; luckily when we got to the beach the rain storm was over.
- The road infrastructure cannot cope with the quantity of rain, thus many of the road have lot of holes, some of the main roads are not paved, and they call travelling in them as the "Costa Rican Massage".
- Tourism has become the biggest industry in Costa Rica, over the last 25 years, which directed the education system towards this goal. Most people can speak English.
- The amount of Israelies we met was incredible given the distance and cost to get there, it seems that it is now quite fashionable among Israelies who already explored Europe and USA to visit Costa Rica.
- Iberia is the worst airline company I have ever used --- in all aspects (including food), the worst thing was that they did not let us get on the connection flight from Madrid to San Jose, Costa Rica, though we got to the gate 15 minutes before the scheduled flights, due to the fact that our flight from Israel was late 1 hour, and they decided they'll not have enough time to load the luggage, though we were 20 passengers coming on that flight, and the fact that they have 1 flight per day to Costa Rica, they did not agree to make any effort to get us on the flight. They told us that since ELAL was responsible for the late flight - it is not their problem (we purchased the ticket from Iberia, and used Iberia ticket with code share). We had to spend 24 hours in Madrid before getting on the next flight -- and lost the first segment of the trip (which is non-refundable as anything else in Costa-Rica). I'll check if it is possible to sue Iberia for damages. The attitude of their agents in Madrid was also very unfriendly - a big difference between the nice people of Costa Rica everywhere, and those of Spain).
- And on positive aspect --- Pura vida --- is a motto of positive thinking!
Now it is a lazy holiday -- back to work early next week, and already a business trip to Europe!