You sat down on a computer to download movies or music from the Internet. The site is immediately displayed in the search engine, the page description of which is entirely consistent with your desire. Click on the link that leads to the desired section of this site, but ...
Error 503 ... An unpleasant surprise, right? This site is probably the only one where music / films can be downloaded for free. And here such a bummer - it is impossible to enter it. Refreshing, refreshing the page - the 503 server error still pops up. Some people quit this business 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. So for them, I will describe today the factors of access to the page of the inscription "Error 503".
What does this mean? That is how the first question sounds among those who stumbled upon a page with this problem. The name of this error means that the service is temporarily unavailable. So is this not for long? The answer to the question of whether the site will be unavailable for a long or not very time depends on its technical capabilities, as well as on you and other visitors to the resource. No, you haven’t mixed up 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 factors for the appearance of a window called "Error 503" - technical and user.
The first one is present if there is some kind of failure on the page, due to which when clicking on the link the user goes to a blank page (for example, the MySQL database is temporarily not working). Then the site administrator places the code of this error on the page so that when typing the exact address of the site, the search engine does not delete the page from the search results, because he sees that this is temporary.
But still, 503 is a mistake most often provoked by users and system problems of their computers. The following is a list of similar reasons.
PHP file transfer of large files
To transfer files, you need to use a special process that processes several streams at the same time, without affecting the site loading speed.
User Solution
The functionality of many document storage scripts can be implemented through the mod_rewrite rules in the .htaccess file.
Remote Server Connection
You need to set a small pause on waiting for a response and make sure that the connection to the remote server is reliable enough. If PHP scripts use Include functions that load parts of the engine located on the same account, make sure that they use not a URL like http: // ..., but a local path. The presence of a URL causes the server to create an additional HTTP request - this slows down the loading of the site.
A large number of spoiled or "heavy" CMS components
Check all the plugins and components of the CMS, turning them off in order of priority, find the most corrupted or “heavy” ones, during which the site loading slows down. If possible, reject such components or look for faster counterparts. Also remove all unnecessary components that are not used by you or whose operation is not mandatory.
Long running mambot job (for Joomla)
If there are jobs among mambot that can be moved to the system cron, then do it. The mambot tasks are executed along with the user’s request, and because of this, loading the site either does not occur at all, or is very slow.
Mailing list
The mailing script is most conveniently placed in the system cron (its control is located on the control panel). And assign it to run at the time of the smallest load on the server (at night). In this case, it is necessary to take into account the limitations in the terms of the offer agreement on the number of letters per hour / day and the PHP script working time.
A large number of server requests- The resource contains links to too many files (style sheets JS-script, pictures), which are added individually. Combine resources into one file where possible.
- 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 several tabs and windows opened by them in the browser.
- Indexers that crawl site resources (Sape, search engines, etc.).
- Using elements of scripts or resources on foreign sites (scripts-informers or links to pictures). Use module / settings anti-identifier.
- DDoS attacks.
That's all the reasons for opening the page with the inscription "Error 503". As you can see, not only the server database, but also the site visitors are to blame for this.