The programmatic way of storing data, so that it can be used efficiently. Almost every enterprise application uses various types of data structures in one or the other way.
Algorithm Introduction
Introduction and Characteristics of Algorithms, Algorithm is a step-by-step programmatic way of storing data, so that it can be used efficiently. Almost every enterprise application uses various types of data structures in one or the other way.
As we saw in this article about Algorithm, Let us see in details here.
Algorithm is step-by-step procedure for solving a problem in finite number of steps. In other words it is finite set of well-defined instructions written in human readable language for solving a given problem. An algorithm is division of a problem into small steps which are in sequence. Algorithm is very important way for computers to understand the problem and process the information accordingly.
Problem can always be solved in multiple ways or can have multiple solutions to solve. Similarly Algorithms also can be written any number ways to solve the problem. Let us see the characteristic of an Algorithm.
As the name suggests the Circuit breaker design pattern is used to stop the process of request and return with the response if a service is not working.
This design pattern can improve the stability and flexibility of an application.
In a distributed environment, calls to remote services and resources can fail due to transient faults, such as slow network connection, timeouts, or the resource being over-committed or temporarily unavailable. These faults typically fix themselves after a short period of time.
However there can also be situations where faults are due to unforeseen events, that might take longer to fix. These faults vary from partial loss of connectivity to complete failure of a service. In these situations, it might be pointless for an application to keep retrying an operation that is unlikely to succeed, instead, the application should accept that the operation has failed and handled this failure accordingly.
A circuit breaker pattern can prevent an application from repeatedly trying to execute an operation that’s likely to fail. Allowing it to continue without waiting for the fault to be fixed or the utilization of resources does not kill the CPU and memory.
It also enables an application to detect whether the fault has been resolved.
How does the Circuit breaker work?
A client should invoke a remote service via a proxy. When the number of consecutive failures crosses a threshold, the circuit breaker trips, and for the duration of a timeout period all attempts to invoke the remote service will fail immediately. After the timeout expires the circuit breaker allows a limited number of test requests to pass through. If those requests succeed the circuit breaker resumes normal operation. Otherwise, if there is a failure the timeout period begins again.
Circuit breaker design pattern
Example:
Consider we have Video Upload and View service when there is a failure in one of the services which triggers the Circuit open and enables the proxy service.
In the next article, we will see the Decomposition design pattern.
CQRS stands for Command Query responsibility segregator, a design pattern that separates the read and update operations for data.
In traditional architecture, the same data mode is used to query and update the data in a database, This is how the CRUD operations work. With CQRS the read and update operations are separated into two parts, Command and Query.
The command part will handle all the CREATE, UPDATE, DELETE requests, while the Query part will handle all the READ (Materialize view) requests.
Advantages of CQRS:
Performance
Scalability
Improves Security
It also prevents update commends from causing merge conflicts at the domain level
Example:
Consider we have Video Services, One for Uploading (Write Operation) and another for viewing (Read Operation).
Where Uploading will perform Create, Update, Delete operations. And the other service on viewing will perform a Select operation to read the videos and their metadata.
In the next article, we will see the Circuit breaker design pattern.
Branch Design pattern extends the Aggregator design pattern and allows us to perform simultaneous response to be processed from two likely mutual exclusive chained services .
This pattern also be called as different chain or Single chain based on the business needs. This design pattern is also known as Branching design pattern.
Example:
Consider the client is booking the Cab. The Trip Service makes call to the Dispatcher service.
Dispatcher service then makes two calls to Passenger & Driver Service, Then these two service calls Notification service.
Business Flow starts like the Client books a Trip, Trip dispatches the request to driver and passenger, then Both Passenger and Driver are notified using the Notification service.
In the next article, we will see the CQRS (Command query responsibility segregator) design pattern.