How to deal with crawler agent failure? Comprehensive solution

The use of proxy IPs is a common and effective means when performing web crawling. However, the failure of proxy IP is an inevitable problem. When the proxy IP fails, the crawler program may encounter problems such as request failures and connection timeouts. In this article, we will explain in detail how to deal with the problem of crawler proxy failure to ensure that your crawler program can run stably and efficiently.

Common Reasons for Proxy IP Failure

1. Proxy IP is blocked by the target website: The target website detected the abnormal behavior of the proxy IP and blocked the IP.

2. Failure of the IP provided by the proxy IP service provider: The IP address provided by the proxy IP service provider may be invalid or no longer available.

3. Proxy IP connection timeout: Proxy servers are slow to respond, causing requests to time out.

4. Proxy IP format error: The proxy IP is not in the correct format and the request cannot be sent.

Ways to deal with proxy IP failures

1. Use of proxy IP pools

To improve the stability of the crawler program, a proxy IP pool can be used. When sending a request, a proxy IP is randomly selected from the proxy IP pool for the request. If a proxy IP fails, you can quickly switch to another proxy IP.

import requests
import random

# proxy pool
proxy_list = [
{'http': 'http://proxy1:port', 'https': 'https://proxy1:port'},
{'http': 'http://proxy2:port', 'https': 'https://proxy2:port'},
{'http': 'http://proxy3:port', 'https': 'https://proxy3:port'}
]

def get_random_proxy():
return random.choice(proxy_list)

def fetch_url(url): return random.choice(proxy_list)
proxy = get_random_proxy()
try: response = requests.get(url): return random.choice(proxy_list)
response = requests.get(url, proxies=proxy, timeout=10)
return response.text
except requests.exceptions.RequestException: return None
RequestException: return None

url = 'http://www.example.com'
content = fetch_url(url)
if content.
print("Request successful")
if content: print("Request successful")
print("Request failed")

2. Detect whether the proxy IP is available

Before using a proxy IP for a request, you can check if the proxy IP is available. This avoids the use of invalid proxy IPs and improves the success rate of the request.

import requests

def check_proxy(proxy)::
try: response = requests.get('', proxies=proxy, timeout=5)
response = requests.get('http://www.example.com', proxies=proxy, timeout=5)
return response.status_code == 200
except: return False
return False

# Proxy IP
proxy = {'http': 'http://your_proxy_ip:port', 'https': 'https://your_proxy_ip:port'}

# Check if a proxy IP is available
if check_proxy(proxy).
print("Proxy is working")
else: print("Proxy is working")
print("Proxy is not working")

3. Setting up a request retry mechanism

When the proxy IP fails, you can set the request retry mechanism to try to resend the request using another proxy IP.

import requests
import random

# proxy pool
proxy_list = [
{'http': 'http://proxy1:port', 'https': 'https://proxy1:port'},
{'http': 'http://proxy2:port', 'https': 'https://proxy2:port'},
{'http': 'http://proxy3:port', 'https': 'https://proxy3:port'}
]

def get_random_proxy():
return random.choice(proxy_list)

def fetch_url_with_retry(url, retries=3): for _ in range(retries): return random.choice(proxy_list): return random.choice(proxy_list).
for _ in range(retries): proxy = get_random_proxy_with_retry(url, retries=3)
proxy = get_random_proxy()
try.
response = requests.get(url, proxies=proxy, timeout=10)
return response.text
except requests.exceptions.
RequestException: continue
except requests.exceptions.RequestException: continue

url = 'http://www.example.com'
content = fetch_url_with_retry(url)
if content.
print("Request successful")
if content: print("Request successful")
print("Request failed after retries")

4. Regularly update the proxy IP

To ensure the availability of proxy IPs, you can periodically obtain new proxy IPs from the proxy IP service provider to replace invalid ones.

# Suppose you have a function that gets a new list of proxy IPs from a proxy IP service provider
def update_proxy_list().
# Here is the code to get the new proxy IP list
new_proxy_list = [
{'http': 'http://new_proxy1:port', 'https': 'https://new_proxy1:port'},
{'http': 'http://new_proxy2:port', 'https': 'https://new_proxy2:port'}
]
return new_proxy_list

# Update the proxy pool periodically
proxy_list = update_proxy_list()

5. Use of highly anonymized proxy IPs

Highly anonymized proxy IPs can better hide the user's real IP address and reduce the risk of being detected by the target website, thus increasing the availability of proxy IPs.

Choose a highly anonymized proxy IP service provider to ensure the quality and anonymity of the proxy IP.

summarize

Proxy IP failure is a common problem in Python crawler development, but by using proxy IP pools, detecting the availability of proxy IPs, setting up a request retry mechanism, updating proxy IPs on a regular basis, and choosing highly anonymous proxy IPs, you can effectively solve this problem and ensure the stable operation of the crawler program.

I hope this article can help you better deal with crawler proxy IP failure and improve your Python crawler skills. I wish you a smooth crawler journey and happy data crawling!