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WS basic conversation patterns
1. request/response: client->server->client
2. solicit/response: server->client->server
3. one-way: client->server
4. notification: server-client


IBM Technical Clouds redbook
"Cluster: A cluster is typically an application or set of applications whose primary aim is to
provide improved performance and/or availability at a lower cost as compared to a single
computing systems having similar capabilities.
Grid: A grid is typically a distributed system of homogeneous or heterogeneous computer
resources for general parallel processing of related workflow usually scheduled using
advanced management policies.
Cloud: A computing cloud is a system (private or public) which allows on demand self service
such as resource creation on demand, dynamic sharing of resources and elasticity of
resource sizing based on advanced workflow models."

Интересное определение кластера у IBM. Ну и очевидная эволюция: cluster -> grid -> clouds.

Добрался до 75-го места по Шотландии. На первые 60 задач ушло где-то 1.5 месяца. На C многие вещи писать сложнее, чем на Perl или Python. Нет встроенной арифметики больших чисел, нет нормальной поддержки массивов. Но надо как-то поддерживать скиллы в старом, добром C. Надеюсь за год добраться до 1-го места, если не надоест. Сейчас больше математики, чем алгоритмики. На больших числах - наоборот. Будет интереснее.

Немного британского рока 70-х

Design by contract
1. Design by contract specifies the obligations of a calling-method and called-method to each other.
2. Preconditions – This is the part of the contract the calling-method must agree to.
3. assert is used for precondition checks in private methods
4. public methods: preconditions are enforced by explicit checks that throw particular, specified exceptions.
5. Postconditions – this is the part of the contract the called-method agrees to.
6. assert is used in both public and private methods.
7. Class invariants - what must be true about each instance of a class: the invariant is an internal class condition
that can specify the relationships between multiple class attributes, and should be true before and after any method completes.

Город, в котором хочу жить


Standard web request
1. Whenever you hit the URL, the browser will contact the DNS server
2. The DNS server will contact the ISP for the required information
3. Once the web server accepts the request from the client browser, it will redirect it to the database server
4. In turn, the database server will retrieve the query and respond it back to the web server
5. The web server then forwards the same response to the client browser
6. Finally, the client browser will display the content to the user

Корни интеллекта

Очень интересное явление. ИМХО, многие формы поведения человека имеют сходную природу. Некоторые алгоритмы оптимизации рутинга в интернете тоже.