Do you know how to find reputable data in a massive amount of data?
Today, we know it as web scraping. The main function of web scraping is to find the data you need most and to make sure that you get original data. The problem is that some of the software blocked the searching process.
So, what do you have to do to prevent block while web scraping process?
How Web Scraping Works?
What you have to know that each of website has different scraping system anytime users access it. The system works to protect and detect the website.
Commonly, web scraping system works when it detects unusual traffic or unusual download rate. It seems impossible for the single client to use such kind of activity in very short time.
Moreover, web scraping also works when the system sees repetitive tasks at once and in short period of time in which it is unusual for the single user to do such kind of activity. There is also the specific system which only detected by the spider or the scraper but it can’t be detected by the users. A specific sign will show anytime scraper or spider tries to open the link.
The Way to Check Website which Doesn’t Want to Be Scrapped
There are specific websites which don’t want to be scrapped. You should know first whether the website is able to be scrapped or not. There are several steps to do to check the website. First, you have to check the certain file known as robots.txt. You can check the file on the root of the website. Second, check the detail of the website especially on the user agent and disallow. When you see the specific sign which is * and / it means the website can’t be scraped.
The Way to Find Website which Blocks You
The problem is that a website might block you and you also want to know who block you, right?
A website can block you in two different ways which are they block all of the access from specific IP and block all of the access from specific ID. By the time websites block you, the browser and web spider will do the process automatically.
As the result, you are unable to access the website anytime you want to visit it. They can block you temporarily or permanent. In temporary banning, you are unable to access websites for a few hours whereas in permanent banning will be much longer.
So, how do you know if a specific website is banning or block you? There are several signs which show that you are blocked by the website such as the CAPCHA pages, unable to open specific pages on the website, and there is specific error sign. If you read specific sign such as 403 Forbidden, 404 not found, or 408 Time Out it means that the website is blocking your access.
The trick to Avoid a Block
Actually, you can avoid banned problem by using specific ways. Let say, you can just slow the crawling speed along with auto throttling method. Moreover, you can also be rotating your IP or creating a pool of IPs which named as the Rotating proxies which good for Web Scraping. This trick will make your IP address difficult to detect. You also need to be careful with Honey Pot traps so the website can’t detect your IP. As the result, the chance to access that website is bigger and you can avoid the block.