(Published for RefinePro, on March 1, 2020. See article.)
Is web scraping easy?
Is it Profitable?
It can, with a great scheduling, monitoring, and maintenance plan.
Your Python skills are not too bad, and it’s not your first time dealing with tech. In fact, technology is part of your daily life. You see the world goes around, and you’ve heard how web scraping could help automate your business.
So, you start looking for the best scrapers and web scraping tools, hoping maybe to boost your e-commerce sales. Not a bad plan in the short term. But what about maintaining your web scraping system? And what will you do when your target websites start updating? And what’s your solution if you get blocked and can’t get the data you need?
Web scraping has opened the door to big data in a world where every market research and business strategy relies on it. But even if the web offers us a plethora of information about “how to,” few take the time to explain the long-term implications of maintaining a web scraping infrastructure.
And that’s because web scraping is not a product. It’s a service. Here’s why.
RUN ON SCHEDULE
The launching of a web scraping project is only the beginning of a long story that can only end well if it involves ongoing and constant scheduling, monitoring, and maintenance.
That’s where we come in.
First, don’t just turn to Google, trying to find the best web scraping agent. That might seem like the first logical step, but it isn’t. Web scraping agents don’t offer all the same scheduling options, so you need to define your goals before you let yourself be convinced by the first “Five Best Tools to Win at Web Scraping” link on Google.
Web scraping without a plan would be like hunting for a needle in a farmer’s hay at night. You might get lucky, but that would still be a really bad bet to make. Every web scraping project should start with a meeting between you and your technical partner, like us, to define your objectives and your needs. What are you trying to achieve with the data? And, more importantly, what kind of data will you need?
The moment when you collect the data will have an impact on its accuracy and usefulness, and it will also affect your choices regarding infrastructure and storage. There’s no point in extracting huge amount of data every day if you don’t have the warehousing capacity to do so, or if your infrastructure can’t process all the requests. Also, websites don’t like to be hammered with requests. You could eventually be banned from accessing their data or worse, be responsible for crashing a whole website with a poorly planned retry strategy.
And that’s why trying to do web scraping all by yourself can quickly become a financial and time-consuming burden. An expert will analyse with you the kind of website you want to retrieve the data from. They will assess how the site behaves, its update frequency, how it removes or adds content, and adjust your schedule accordingly. Most importantly, a good web scraping service provider will include trials and errors in its planning, knowing that it might be necessary to take a few passes at a webpage to identify patterns and adjust the scraper accordingly.
You also need to anticipate the consequences of missing data and have a process in place to retry all the missed pages. What’s your plan if you’re suddenly blocked from a site and can’t get the data you need?
Scheduling is not only about “how often” and “when.” Most importantly, it depends on the data you’re trying to extract, and the webpages you are extracting it from. And once your schedule is set and launched, monitoring your web scraping activities suddenly takes on a whole new meaning.
DON’T NEGLECT YOUR SCRAPPER! MONITOR!
You remember our guy hunting for a needle in a farmer’s hay? Let’s say someone finally gave him a map and a flashlight, and now he has his needle. His job is done, right? In Web scraping, your job is never really done. And that’s why it’s nothing like hunting for a needle in a haystack.
Websites get updated all the time. Sometimes on a pre-defined schedule, but most of the time not. To maintain the performance of your web scraping operations, you need to keep track of these changes and run quality checks to avoid data loss. And monitoring these activities and tweaking the system accordingly often requires extensive knowledge of the technologies involved.
Especially when proxies are used.
Essentially, a proxy is an extra server installed between you and the site you’re trying to reach. They’re an important part of most web scraping projects as they will help you tackle a lot of the common challenges. You remember when we said that scheduling could help you not be banned from websites? So does a proxy. When you send a request to a website using a proxy, the request will not be linked to your own IP address, it will take the IP address of your proxy server. This way, you can hide your IP address from the websites and send different requests using different proxies that will not be identified as coming from the same person.
Another thing proxies will do for you, is letting you get past rate limits. Large websites usually use software that will detect when a large number of requests are coming from one IP address. This software doesn’t make the difference between real security threats and harmless and respectful web scraping. They will block you, forcing you to wait and possibly face a loss of data. An expert will help you avoid these problems by setting a pool of proxy servers. This way, your requests are sent to different websites using different IP addresses, leaving you free to extract the data you need.
RefinePro, for example, works with Luminati proxy management software, which offers a customizable and integrated solution. They combine their knowledge with Luminati’s Proxy Manager to define a cost-effective IP rotation strategy that meets their clients needs. They also help you monitor your web scraping operations so that you can rely on your system performance and the quality of your data.
When a bug occurs, and it will occur, the first thing to do is to determine whether it’s coming from your code or the website. These bugs can affect both the performance of your web scraping, but also the quality of your data. That’s why it’s important to sit down with an expert to develop both a monitoring and bug fixing strategy, and to make sure your transformation process is strong enough to help you detect any problem in the quality of your data.
In the long term, this will also help you maintain your web scraping structure.
ANTICIPATE SURPRISES WITH MAINTENANCE
Your web scraping platform needs to perform a lot of different tasks and maintain a
complex infrastructure. It needs to deploy and run your crawlers, deploy pattern change detectors, integrate quality assurance systems, run a pool of proxies, etc. For the whole system to work, each component must be properly integrated, and the end result must still meet your goals.
Having the right product is not enough.
Once your scraping project is deployed, you’ll need to keep it updated on an ongoing basis. This maintenance is necessary to cope with changes in the target websites and systems. And developing and maintaining such a system requires a lot of resources, both human and monetary. Often, organizations with small web scraping projects feel like they can only grab their old dusty copy of “Python for Dummies” from the shelves to get them going. But even small web scraping projects require you to trigger off a lot of systems in parallel and to monitor and maintain them nonstop. That alone is a major cost driver.
When you work with an expert, they will agree with you on a plan that answers your data needs and respect your budget. Scheduling, monitoring, and maintaining your system are the most cost- and time-consuming aspects of a web data extraction project. But they’re also the most important ones. Writing the actual script is one thing. Running it to meet your service level agreement is another.
At the end, data collection delivers lasting value only when you’re able to keep the data current.
AND WITH THAT
Web scraping tools are not hard to find on the Internet. But you should never underestimate the effort needed to monitor and maintain a web scraping infrastructure. Writing the code is one thing, but defining the right scope is another. Your script must be easy to scale, to monitor, and to maintain. You must be ready to make constant updates as you become more knowledgeable about your target websites.
We’ve said it before, and we’ll say it again: web scraping is not a tool. It’s a service.
So, if you’re looking for a web scraper, start looking for a web scraping service instead.