As a web crawler engineer with more than ten years of experience, I know well the key points of each link of crawler data collection. In this article, I will explain what an “ip pool” is, why crawler collection needs to use an “ip pool”, and what advantages residential IP pools have over data center IP pools from the perspective of application fields.

First of all, what is an “ip pool”? Simply put, an ip pool is a group of different ip addresses that can be used to access the target website. An ip address is a unique identifier for each device on the Internet, which can be compared to a phone number. When we use a crawler program to crawl data from a website, we need to establish a connection and send requests through an ip address. However, not all ip addresses can access any website freely. Some websites will check the ip address of the visitor to prevent malicious crawler programs from causing burden or infringing their copyright. If an ip address is found to frequently access the same website, or send abnormal requests, then this ip address may be blocked by the website, resulting in inability to continue access. This is why we need to use an “ip pool”.

The benefit of using an “ip pool” is that we can rotate access to the target website through different ip addresses, thereby reducing the risk of being blocked. At the same time, we can also choose the appropriate ip address according to different websites, to improve the efficiency and stability of the crawler program. For example, some websites will display different content based on the visitor’s location, if we want to get specific information from a certain country or region, we need to use the ip address of that country or region to access. In this way, we can get more accurate and comprehensive data.

So, what types of “ip pools” are there? Generally speaking, “ip pools” can be divided into two major categories: data center IP pools and residential IP pools. Data center IP pools are those IP addresses provided by professional institutions, usually those owned by servers or cloud service providers. These IP addresses have the advantages of large quantity, low price, fast speed, and high stability, but the disadvantage is that they are easy to be recognized and blocked by the target website, because they often belong to the same network segment or domain name. Residential IP pools are those IP addresses provided by ordinary users, usually those assigned by broadband networks used by homes or offices. These IP addresses have the advantages of being difficult to be recognized and blocked by the target website, because they often belong to different network segments and domain names, and have authenticity and diversity. But the disadvantage is that they are small in quantity, high in price, slow in speed, and low in stability.

In summary, according to different application scenarios and needs, we can choose the appropriate “ip pool” to improve the effect and quality of crawler data collection. In my work experience, I found that residential IP pools have obvious advantages over data center IP pools, especially for those websites that have strict anti-crawler measures, such as Google, Amazon, Facebook and so on. Using residential IP pools, I can more easily break through these websites’ restrictions and get more data. Of course, residential IP pools also have their limitations, such as high cost, slow speed, low availability and so on. Therefore, I suggest that when using residential IP pools, you should combine some other technologies and strategies, such as proxy manager, request delay, request header setting, captcha recognition and so on, to achieve the best crawler effect.