There is a limitation to CPU and RAM resources on every servers. Many websites, like Wordpress for example, run on PHP. When a user visits your Wordpress site, the server executes Wordpress’ PHP code and creates your web page. The CPU on the server executes the PHP code. If you experience very high CPU or load average, your website may be unable to keep up with all the requests it has to execute PHP scripts and it will come to a crawl. In this article we going to cover the common reasons why some accounts have excessive resources usage.
MySQL activity
This can mean many different things. MySQL refers to your site’s database(s). For example, if you have a Wordpress website, it uses MySQL to store your website’s content in a database.
If your website has long running MySQL queries (asking the database for too much information) or excessive amounts of querying (asking the database for more information repetitively) it can cause your website to load slowly or even crash.
Poorly coded Scripts/ Plugins/ Modules
It is a common misconception that all websites have the same CPU / Memory usage. This is not the case though. For example, a Wordpress website with a default theme and no plugins uses far less memory than another Wordpress website with a custom theme and 20 plugins. Also, keep in mind that a website with one poorly coded plugin can cause more CPU and memory usage than a website with 20 well-coded plugins.
Sometimes it is as simple as updating your plugins and scripts to the latest versions. Most developers will update their code to address resource usage and fix security holes. If your website is custom coded you may need to examine the code or contact the developers who built the website for you.
Cron Jobs running too often
Cron Jobs are basic task schedulers. This allows you to schedule a script to run in specific increments like every minute, every hour, or every day. Cron jobs that aren’t configured properly or ran too often can cause high server loads which can affect how your site loads.
High Traffic
High traffic isn’t a bad thing. This means your website is getting a
lot of visitors and is probably a goal for you. You may have simply outgrown your current
hosting plan and it may be time to upgrade to a different plan that
better suits the needs of your website.
Search Engines Overly Crawling Site
At times, we see our customer’s sites being crawled excessively by search engine bots. Having your site indexed by the search engines can be important so people can find your website. There comes a point however, where the search engines can be over crawling your site which can affect your site’s ability to function as you have intended it.
Over-crawling your site can mean different things. Google and other
search engines can be crawling too many pages of your website,
especially ones that you do not want the public to see. Also, over
crawling can mean they are making too many requests to the server. You might then need a robots.txt to control the search engine crawlers.