How the scrapy framework automatically runs on the cloud server

In the process of web crawling, the scrapy framework is a very convenient and fast tool. In order to achieve automated web crawling, we can deploy the scrapy framework on the cloud server. This article will introduce how to automatically run the scrapy framework on a cloud server.

1. Select a cloud server

First, we need to select a cloud server to run the scrapy framework. Currently, the more popular cloud server providers include Alibaba Cloud, Tencent Cloud, Huawei Cloud, etc. These cloud servers have different hardware configurations and billing methods, and we can choose according to our needs.

When choosing a cloud server, you need to pay attention to the following points:

1. Whether the hardware configuration of the server meets the requirements.

2. Is the geographical location of the server within the area of the website you need to crawl? This can reduce network latency.

3. Whether the server provider's billing method is reasonable and whether there is sufficient budget.

2. Connect to the cloud server

Connecting to the cloud server can be done using command line tools or through the web management platform provided by the provider. The steps to use the command line tool to connect to the cloud server are as follows:

1. Open the command line tool and enter ssh root@ip_address, where ip_address is the public IP address of the cloud server you purchased.

2. Enter the server login password for verification and enter the server.

You need to pay attention to the following points when connecting to the cloud server:

1. Please keep the login password of the cloud server properly to avoid leakage.

2. Please pay attention to the settings of firewall and security group to ensure that the outside world cannot illegally access your cloud server.

3. Install the scrapy framework

After successfully connecting to the cloud server, we need to install the scrapy framework on the server. The steps to install the scrapy framework on the cloud server are as follows:

1. Use pip to install the scrapy framework and enter the command pip install scrapy to complete.

2. If pip is not installed on the server, you can use yum to install it and enter the command yum install python-pip.

When installing the scrapy framework, you need to pay attention to the following points:

1. When installing the scrapy framework, you need to ensure that the Python environment has been installed on the cloud server.

2. After the installation is complete, you can use the scrapy -h command to test whether the installation is successful.

4. Write a scrapy crawler program

After installing the scrapy framework on the cloud server, we need to write a scrapy crawler program. Enter the command scrapy startproject project_name to create a new scrapy project.

You can then create a spider crawler in a new project and enter the command scrapy genspider spider_name spider_url to create a new spider crawler, where spider_name is the name of the crawler and spider_url is the URL of the website to be crawled by the crawler.

When writing a scrapy crawler program, you need to pay attention to the following points:

1. You need to carefully analyze the website structure to determine the web page content to be crawled and the crawling method.

2. The crawler crawling speed needs to be set to avoid excessive pressure and impact on the target website.

3. It is necessary to set up the exception handling mechanism of the crawler to avoid crawling failure due to network problems or server problems.

5. Configuring automated crawling tasks

Configuring automated crawling tasks is a key step to realize the automatic operation of the scrapy framework. We can use tools such as crontab or supervisor to achieve this.

Taking crontab as an example, we need to perform the following steps:

1. Enter the command crontab -e and enter the configuration information of the automation task in the open text editor.

2. Enter relevant information such as the path of the script file to be run and the running time interval in the configuration information.

You need to pay attention to the following points when configuring automated crawling tasks:

1. The configuration information format needs to comply with the UNIX crontab specification.

2. The running time interval needs to be set to avoid excessive load caused by too frequent intervals, or the interval is too long and requires manual running.

3. You need to carefully check whether the script file path is correct and whether the executable permissions are set correctly.

6. Summary

To realize the automatic operation of the scrapy framework on the cloud server, you need to select the cloud server, connect to the cloud server, install the scrapy framework, write the scrapy crawler program, and configure automated crawling tasks, etc. Multiple steps. Through the above steps, we can easily implement automatic crawling of web pages and obtain data that meets crawling needs.

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