Web crawler is a technology to obtain and crawl information on the network, and the use of IP proxy can help crawler to protect privacy and improve access efficiency when obtaining information. However, when using IP proxies for web crawlers, we also need to pay attention to some important things to ensure the smooth operation of the crawler and the reliability of the data.
Here are a few key things to look out for when using an IP proxy for web crawlers:
1, API extract link: Ensuring that the proxy IP can be correctly extracted is critical to using the IP proxy. In the Settings of some software or tools, there may be problems that cause the IP to not be extracted correctly, or the IP format returned does not meet the requirements. This may be due to a misconfiguration of the Settings or a mismatch in the format of the data returned by the interface.
Also, you need to be careful when dealing with IP, especially when dealing with IP address separators. Some users may not handle delimiters properly when dealing with IP, resulting in only the first IP address being available and subsequent IP addresses failing. This may lead to poor use of proxy IP, and even affect the normal operation of the crawler.
2, IP proxy authorization: Many paid IP proxy services require user authorization to use, which can increase the security and credibility of the agent. Common authorization modes include IP whitelist, user name, and password, or both.
If the IP proxy cannot be used, you need to check whether the authorization is correctly configured. Here are some things to look out for:
IP whitelist authorization: If the proxy service provider uses the IP whitelist authorization mode, ensure that the terminal IP addresses that need to use the proxy are correctly added to the whitelist. Only the IP addresses listed in the whitelist can successfully use the proxy. If the IP address changes or the terminal IP address is incorrectly configured, the agent cannot work properly.
User name and Password authorization: For agent services that use user name and password authorization, ensure that the user name and password information provided is accurate and consistent with the authorization information provided by the agent service provider. Any errors or misspellings may result in unsuccessful authorization.
Check the authorization mode: Sometimes, the proxy service provider may support both IP whitelist and username and password authorization. In this case, make sure you choose the right authorization method and provide the appropriate information according to the authorization method. Confusing or incorrect authorization may result in unsuccessful use of the agent.
Update Authorization information: If the agent changes the authorization information, such as changing the whitelist IP address or changing the user name and password, please update your authorization information in a timely manner. Making sure to use the most up-to-date authorization information can prevent an agent from being unavailable due to expired or invalid authorization.
Proper authorization Settings are key to the proper operation of the agent. Ensure that the terminal IP address is correctly added to the IP address whitelist or the user name and password are correct to ensure that you can use the proxy service successfully.
3, access strategy: Sometimes, even if the Settings and code are correct, still can not successfully access the target website, or the success rate is very low. In some cases, websites that were previously able to be successfully accessed suddenly failed or had a very high failure rate. In this case, you first need to determine if the IP proxy is working properly. An easy way to do this is to set up a browser proxy and try to access the target website directly through your browser. If the browser can be successfully accessed, but the program code cannot, then it is probably a problem with the access policy.
Here are some common access policy problems and their solutions:
Frequency limits: Some websites set frequency limits on requests from the same IP address, denying access or returning error messages when the requests are too frequent. In this case, you can try to avoid being restricted by slowing down the frequency of requests and increasing the time between requests. You can also use a proxy pool to rotate multiple IP addresses to reduce the risk of a single IP being restricted.
Verification code recognition: Many websites set up verification codes to prevent bots from accessing them. The crawler cannot automatically recognize the verification code when it encounters it, resulting in an access failure. The solution can be to use a third-party CAPTCHA recognition service, manually enter the captcha, or simulate user behavior to solve the captcha problem.
User login and session management: Some websites require users to log in to access specific content, or to maintain state in a session. When crawling such websites using IP proxies, care needs to be taken to simulate user login and manage session state to ensure the validity of the request. You can use the user session management capabilities provided by crawler frameworks or libraries to deal with these issues.
Although the use of IP proxies can assist in the crawling work, it does not mean that the use of proxies can completely avoid restrictions. Even if you use a proxy, follow the site's access rules and restrictions. Reasonable operation and crawling according to normal access flow are the key to ensure smooth web crawling.
In short, using IP proxy for web crawler needs to pay attention to the correctness of API extraction link, the accuracy of IP proxy authorization and the rationality of access strategy. Following these matters ensures the proper operation of the crawler and makes data acquisition more reliable and stable.