A proxy server is an intermediary between the crawler and the target website, providing the crawler with an IP address. Using a proxy allows anonymity to be maintained when performing crawler tasks, as the visited website will only see the IP address of the proxy and will not directly expose the crawler's own IP address. This is especially important when doing large-scale web crawling, as frequently sending multiple requests from a single IP address can trigger the target website's defense mechanisms, resulting in the crawler's IP address being blocked.
There are different types of proxies that can be used in web scraping, each with its own advantages and disadvantages:
1, Data center agent: A data center agent is an agent that is resold by the agent service provider after purchasing from the data center. They are typically provided in the form of server clusters with a large number of IP address resources. In web scraping, many people will consider using data center agents because they are relatively inexpensive and numerous, making them suitable for large-scale data collection tasks. However, there are some drawbacks to using a data center proxy, the most notable of which is being easily identified as a proxy by the target website.
Since the IP addresses of the data center agents all come from the data center, these IP addresses may have similar characteristics and origins, making it easy for the target website to detect them. Some websites will take preventive measures, using various means to detect and block proxy IP addresses, in order to prevent abnormal crawling activities, protect the security and stability of website data. When a website detects a large number of requests from data center proxies, it is likely to blacklist those proxy ips and quickly block them, making it impossible for crawlers to continue accessing and scraping data.
In addition, data center agents often do not have the behavioral characteristics of real users, which is one of the bases that some websites use to distinguish between crawlers and real users. The website may identify the user's behavioral characteristics such as visit frequency, click pattern, and visit period, so as to block IP addresses that do not conform to real user behavior.
In order to avoid the data center agent being blocked by the target site, there are some measures that the crawler can consider taking. The first is to choose a high-quality data center proxy provider, who may provide better IP addresses and better proxy services, reducing the risk of being blocked. Secondly, IP rotation technology can be used to simulate the behavior of real users by periodically switching different proxy IP addresses, reducing the possibility of detection. In addition, other types of agents, such as residential agents or mobile agents, can be combined with data center agents to increase diversity and further improve the efficiency and success rate of scraping.
2, residential agents: Unlike data center agents, residential agents and mobile agents are more suitable for network crawling, because they have more real user behavior characteristics, and are not easy to be detected by the target website to use agents.
The IP address of the residential agent is provided by the real home Internet connection, which means that these IP addresses represent the online behavior of the real user. Because residential agents are provided by the average user's own network connection, their IP address does not look much different from the average user's IP. This makes the residential agent more secretive and hidden, not easy to be found and identified by the target website.
In contrast, data center brokers' IP addresses are often purchased from data centers and resold by proxy service providers, and these IP addresses have similar characteristics that can be easily detected by websites. Residential agents, on the other hand, are closer to the online behavior of real users, so it is easier to use residential agents on certain websites as normal users without being blocked.
Residential agents and mobile agents generally do not arouse too much suspicion because their IP addresses represent real individual users, and real users' online behavior on the Internet has a certain degree of randomness and diversity. This makes residential agents more reliable when carrying out large-scale web crawls and is not easy to be identified as agents by target websites.
Regardless of the type of proxy used, implementing IP rotation is a key step in improving the efficiency of crawlers. Through IP rotation, crawlers switch to use different IP addresses at certain intervals. This makes the server of the target site think that each request is coming from a different user, reducing the likelihood that the IP will be blocked and increasing the chance of a successful web scraping task.
In general, crawlers using proxies can effectively hide the real IP address, circumvent the restrictions of the target website, and improve the efficiency and success rate of crawling. Choosing the right proxy type and implementing IP rotation will provide a better network crawling experience for crawlers.