Retry and failure handling in Rest API

Introduction

Sometimes, when you ask a server for information, it might not respond right away or may have a problem. Retry and failure handling helps your program try again or handle errors smoothly so users don't get stuck or confused.

When your app calls a web service that might be temporarily down.

When network connections are unstable and requests can fail.

When you want to make sure important data is sent even if the first try fails.

When you want to show a friendly message if the server cannot be reached after several tries.

Syntax

Rest API

def retry_request(url, max_retries=3, delay=2):
    for attempt in range(max_retries):
        response = send_request(url)
        if response.is_success():
            return response.data
        wait(delay)
    handle_failure()

retry_request is a function that tries to get data multiple times.

max_retries is how many times it tries before giving up.

Examples

Try up to 5 times, waiting 1 second between tries.

Rest API

retry_request('https://api.example.com/data', max_retries=5, delay=1)

Try 3 times by default, waiting 2 seconds between tries.

Rest API

retry_request('https://api.example.com/data')

Sample Program

This program tries to get data from a fake URL. It tries up to 3 times, waiting 2 seconds between tries. It prints messages to show what is happening. If all tries fail, it prints a failure message and returns None.

Rest API

import time
import random

def send_request(url):
    # Simulate a request that fails randomly
    if random.random() < 0.7:
        return type('Response', (), {'is_success': lambda self: False, 'data': None})()
    else:
        return type('Response', (), {'is_success': lambda self: True, 'data': 'Success!'})()

def retry_request(url, max_retries=3, delay=2):
    for attempt in range(1, max_retries + 1):
        print(f'Attempt {attempt} to fetch data...')
        response = send_request(url)
        if response.is_success():
            print('Request succeeded!')
            return response.data
        else:
            print('Request failed, retrying...')
            time.sleep(delay)
    print('All retries failed. Handling failure.')
    return None

result = retry_request('https://api.example.com/data')
print('Final result:', result)

Important Notes

Always set a limit on retries to avoid endless loops.

Use delays between retries to give the server time to recover.

Handle failure gracefully to keep users informed and avoid crashes.

Summary

Retry and failure handling helps your app try again when requests fail.

Set a maximum number of retries and wait time between tries.

Always handle the case when all retries fail to keep your app stable.