Synchronous Request
A synchronous request is a type of HTTP request where the client waits for the server to respond before continuing. It blocks the execution of further code until the response is received.
Also known as: Blocking Request, Sequential Request, Serialized Request.
Comparisons
- Synchronous vs. Asynchronous. Synchronous is when execution waits for the response, asynchronous - execution continues while waiting for the response.
- Blocking vs. Non-blocking. Blocking (synchronous) is when the program halts further operations until the task completes, non-blocking (asynchronous) - the program moves on to other tasks while waiting.
- Sequential vs. Concurrent. Sequential (synchronous) is when tasks are executed one after the other, concurrent (asynchronous) - multiple tasks can execute simultaneously or overlap.
- Request-Wait vs. Fire-and-Forget. Request-Wait (synchronous) is when the client sends a request and waits for a reply, Fire-and-Forget (asynchronous) - the client sends a request without waiting for a response.
Pros
- Simplicity. Easier to implement and understand due to straightforward flow.
- Predictable Behavior. Code execution happens in a clear, sequential order.
- Easier Debugging. Errors and issues are easier to trace since execution pauses at the request.
- Order Preservation. Requests are handled one at a time, ensuring proper sequence.
Cons
- Performance Bottleneck. Blocks the execution of other tasks, leading to slower performance, especially in high-latency operations.
- Scalability Issues. Poor for systems that need to handle many simultaneous requests.
- Resource Inefficiency. The system sits idle while waiting for a response, wasting CPU cycles.
- Poor User Experience. In client-facing applications, users might experience lag or freezing during requests.
Example
In Python:
import requests# URL to scrapeurl = "https://example.com"# Synchronous HTTP GET requestresponse = requests.get(url)# Execution pauses here until the response is receivedif response.status_code == 200:print("Page content:", response.text) # Process the responseelse:print("Failed to retrieve the page. Status code:", response.status_code)# Code after the request only runs once the response is receivedprint("Request completed.")