Practices and Principles of Combining Java Async HTTP Client Framework with Circuit Breake
Analysis and principle analysis of Java asynchronous HTTP client framework and fuse combination
In distributed systems, due to the uncertainty of factors such as network and service response speed, relying on the call of external services often causes many potential problems.These problems may lead to increased system delay, exhaustion of resources, and even the system.To solve these problems, we can use the Java asynchronous HTTP client framework with the fuse.This article will explore this combination of practice and principles.
1. Why use asynchronous HTTP client framework?
The traditional HTTP client is usually synchronized, that is, the blocking thread after the request is required until the response is received.Such a blocking model is inefficient in high concurrency scenes and easily leads to exhaustion of resources.The asynchronous HTTP client framework allows us to return the thread immediately after sending the request and process the response through a callback.This asynchronous model can greatly improve the throughput and concurrent performance of the system.
2. What is a fuse?
The fuse is a mechanism for protecting the external dependencies in the distributed system.When an external dependent service fails or abnormalities, the fuse will prevent the call of the service from the expansion of the problem within a period of time.The fuse also provides a fast failure mechanism, which directly returns the default default response to the pre -defined to avoid waiting timeout.The fuse can monitor the success rate, failure rate and other indicators, and automatically open or close according to these indicators.
3. Practice
Below we will combine a practical example to introduce how to use the Java asynchronous HTTP client framework with the fuse.
First of all, we need to introduce the dependencies of asynchronous HTTP client framework and fuse. For example, using Apache HTTPClient and Hystrix:
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpasyncclient</artifactId>
<version>4.1.3</version>
</dependency>
<dependency>
<groupId>com.netflix.hystrix</groupId>
<artifactId>hystrix-core</artifactId>
<version>1.5.6</version>
</dependency>
Next, we can use the asynchronous HTTP client to send a request and deal with response.The following is a simple example:
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.concurrent.FutureCallback;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClients;
public class AsyncHttpClientExample {
public static void main(String[] args) throws Exception {
CloseableHttpAsyncClient httpClient = HttpAsyncClients.createDefault();
httpClient.start();
HttpGet request = new HttpGet("https://api.example.com/data");
httpClient.execute(request, new FutureCallback<HttpResponse>() {
@Override
public void completed(HttpResponse httpResponse) {
// Successful response
}
@Override
public void failed(Exception e) {
// Treatment abnormal situation
}
@Override
public void cancelled() {
// Process request cancellation situation
}
});
}
}
We then need to use a fuse to protect external dependencies.The following is an example of using Hystrix:
import com.netflix.hystrix.HystrixCommand;
import com.netflix.hystrix.HystrixCommandGroupKey;
public class ExternalServiceCommand extends HystrixCommand<String> {
public ExternalServiceCommand() {
super(HystrixCommandGroupKey.Factory.asKey("ExternalServiceGroup"));
}
@Override
protected String run() throws Exception {
// Call external service
return "Response from external service";
}
@Override
protected String getFallback() {
// Return a default response to avoid waiting timeout
return "Default response";
}
}
Finally, we can use the above asynchronous HTTP client and fuse where external services need to call external services:
import com.netflix.hystrix.HystrixCommand;
public class ServiceClient {
public String callExternalService() {
HystrixCommand<String> command = new ExternalServiceCommand();
return command.execute();
}
}
Through the above steps, we successfully combined the Java asynchronous HTTP client framework with the fuse to improve the stability and performance of the system.
5. Primary analysis
The asynchronous HTTP client framework processs requests and responses through non -blocking I/O processing requests to improve the throughput and concurrent performance of the system.It uses a thread pool to process the request, and to deal with the response through the callback function to avoid the blocking of the thread.
The fuses are automatically opened or closed based on these indicators through cache request results, timing statistical success rates and failure rates, and based on these indicators, play a role in protecting the dependence of the distributed system.When the fuse is opened, the default response will be quickly returned to avoid waste and waiting for resources.
Combined with the use of asynchronous HTTP client frameworks and fuses, we can achieve high -efficiency calls and protection of external services to improve the stability and performance of the system.
Summarize
This article introduces the practice and principle analysis of the combination of Java asynchronous HTTP client framework and fuse.By using the asynchronous HTTP client framework and fuse, we can improve the throughput and concurrency performance of the system, while protecting the system from the impact of potential problems of external dependencies.It is hoped that this article will help readers' applications in actual development.
