Error 503. What is the reason?

You have sat down at the computer to download movies or music from the Internet. In the search engine immediately issued a website, the description of the page which entirely corresponds to your desire. Click the link that leads to the desired section of this site, but ...

Error 503 ... Unpleasant surprise, right? This site is probably the only one on which music / movies can be downloaded for free. And here such a bummer - it is impossible to go. Updating-updating the page - still jumps server error 503. Some people drop this case and look for content on other sites. And some seek to find out the cause of the problem in order to avoid such misunderstandings in the future. Here for them I will describe today the factors of the exit to the page of the inscription "Error 503".

What does this mean? This is how the first question sounds among those who come across a page with this problem. The name of this error indicates that the service is temporarily unavailable. So it's not for long? The answer to the question of whether the site will be inaccessible for a long time or not, depends on its technical capabilities, as well as from you and other visitors to the resource. No, you have not confused the words, site visitors can also be the cause of this error. But let's talk about everything in order. So, there are only two reasons for the appearance of a window with the name "Error 503" - technical and user.

The first is present in the event that the page has some kind of failure, because of which when clicking on the link the user goes to a blank page (for example, the MySQL database does not work temporarily). Then the site administrator places on the page the code for this particular error, so that when typing the exact site address, the search engine does not delete the page from the search results. He sees that this is temporary.

But still 503 is a mistake, most often provoked by users and system problems of their computers. Below is a list of similar reasons.

Transfer large files with PHP-language

To transfer files, you need to use a special process that processes several threads simultaneously, without affecting the download speed of the site.

Troubleshooting by the User

The functionality of the set of document storage scripts can be implemented through mod_rewrite rules in the .htaccess file.

Connecting to a remote server

It is necessary to set a small pause for waiting for an answer and make sure that the connection to the remote server is reliable enough. If you use Include functions in PHP scripts that load parts of the engine that are on the same account, make sure that they do not use the http: // ... URL, but the local path. The presence of the URL causes the server to create an additional HTTP request - this slows down the loading of the site in order.

A large number of spoiled or "heavy" CMS components

Check all plug-ins and components of the CMS, turning them off in the order of the queue, find the most spoiled or "heavy", with the work of which slows down the site load. If possible, reject such components or look for faster analogs. Also remove any unnecessary components that are not used by you or whose operation is not mandatory.

A long-running task for mambot (for Joomla)

If there are jobs among mambot that can be moved to the system cron, then do it. The mambot jobs are executed along with the user's request, and because of this, the site load either does not happen at all, or is very slow.

Mailing list

The script of mailing is most conveniently placed in the system cron (its control is on the control panel). And assign it to run for the time of the least load on the server (at night). In this case, it is necessary to take into account the limitations in terms of the contract-offer on the number of letters per hour / day and the time of the PHP script.

A large number of requests to the server

1. The resource contains links to too many files (JS script style tables, pictures), which are added each individually. Merge resources into one file, wherever possible.
2. The site has an element that sometimes sends AJAX requests to the server (for example, chat). The number of requests depends not only on the number of visitors, but also on the opening of several tabs and windows in the browser.
3. Indexers that scan sites' resources (Sape, search engines, etc.).
4. Use of script elements or resources on other sites (script informers or links to pictures). Use the module / configuration anti-determinator.
5. DDoS attacks.

That's all the reasons for opening the page with the inscription "Error 503". As you can see, this is not only the database server's fault, but also the site visitors.