During the surfing on the Internet, each of us came across the appearance of the message "Error 503 - Service Unavailable" when accessing the site, which even recently worked correctly. This code It means that the HTTP resource you want to go is temporarily inaccessible.
As evidenced by "Error 503"
Each accountThe hosting has a certain amount workflowswhich is strictly regulated by features tariff plan. Request processing from other network computers is carried out in order of arrival. At the same time, easy requests can be processed almost instantly, and for working with heavier required for some time.
This queue is limited to a certain number of requests, and in case of exceeding the limit, the query deviates, and the user's browser shows the message "ERROR 503".
What to do the user when the error code 503 appears in the browser
Most often, the cause of such behavior of the server and the appearance of an error with code 503 are temporary problems, and after a while the server frees the required amount of resources and can process the request. That is why it is recommended not to enter the site for three minutes, so as not to create another queue consisting of contacting a hosting computer, which can only aggravate the current situation.
Causes of Error Error 503 - Service Unavailable
Code 503 indicates the formation of a large query queue on the server with which he does not have time to cope. The main reasons for the formation of the queue can be:
- Hanging scripts.
- A large number of appeals to the server.
Causes of scripting and methods to combat this problem
Enlightening scripts and the further appearance of the error "ERROR 503 - Service Unavailable" may be caused by the following factors:
- File transfer big size for help php.. Large files are recommended to be transmitted directly, without using scripts for two main reasons:
- scripts have limited time work, and after its expiration, the transfer will be interrupted;
- file transmission using PHP takes a separate process that stops processing user requests.
- File transfer It is recommended to organize directly using a special multithreaded process processing a large number of threads at a time and does not affect the download speed of the HTTP resource.
- Connections with remote servers. This type of connection is strictly recommended to avoid, but if without them it is impossible to implement the work of the site, then you should set a small response time and configure good communication With a remote server.
- A large number of "heavy" or non-working CMS modules. Absolutely all the plugins used by CMS must be checked for performance and resource intensity. Modules that slow down the site are recommended to be replaced by more nailed counterparts, moreover, it is better to uninstall all unused engine components.
- Illiterate use of mailing list. The mailbox script is recommended to run only with minimal load on the server (for example, at night), given the limitations of the number of messages per day and the features of the script.
- Slow requests K. mySQL database. If you have slow requests in the account, a file with the name of MySQL-Slow.log appears. This file data is updated once a day and contain exclusively problem requests for the database. In order to minimize the number of slow requests and, therefore, reduce the frequency of error with code 503, it is recommended:
- install on the site of the site caching components that reduce the number of queries to the database;
- optimize the requests themselves;
- index the tables of the database on the columns used in samples;
- change CMS site.
Causes of a large number of requests to HTTP resource
To a large number of requests and, as a result, the error with the code 503 "Service Unavailable" can provide:
- content on the website of HTTP links to a very large number of files loaded through separate queries (images, tables, Java scripts can be used as such files);
- the presence on the website of the element periodically sending AJAX requests to the server (for example, chat), and the number of requests will depend on both the number of visitors and the number of open tabs in the browser of one visitor;
- indexing bots that scan the resources of the site (for example, all sorts of search engines);
- the use of any resources that are posted on other sites;
- DDOS attacks.
A number of users in their work with any site can meet with an error 503 and the SERVICE TEMPORARIY UNAVAILABLE message. Specified error It may concern both developers of any resources and ordinary users trying to go to a specific site and collided with this problem. In this material I will tell you that it means 503 Service Temporarily Unavailable, list the list of reasons that cause these dysfunction, and explain how to fix it.
What is this 503 Service Temporarily Unavailable (Translation into Russian)
Translated into Russian text errors 503 sounds like "503 service is temporarily unavailable" And usually concerns the situation when the service under consideration (resource) does not have time to process all appeals to it, and for a while ceases to accept new requests for this address.
This error 503 is one of the standard HTTP state codes, and usually manifests itself with such standard clichés as "503 Service Unavailable", "HTTP Server Error 503", "503 Error", "Error 503" and near others. The problem occurs when the browser is working in any modern operating systemwhere the Internet connection is activated.
Causes of errors "Service temporarily unavailable 503"
In most cases, the main cause of the error 503 is the overload of the server or execution on it in this moment any technical work. And the sites that use Microsoft Internet Information Services can give more information about the causes of the error 503, adding the error code to the error code also and the number of the specification (for example, the error 503.2 - Concurrent Request Limit Exceeded - the limit of parallel requests is exceeded and so on)
In addition to a large number of requests to the web server, the causes of the error 503 Service Temporarily Unavailable may be as follows:
How to get rid of errors 503 (section for users)
Although, in most cases, the error 503 Service Temporarily Unavailable is the problem of developers, there are situations where users can correct the situation (although, being objective, there are no such opportunities). Below I will list what an ordinary user may take on how to get rid of the 503 error:
How to get rid of the problem of 503 Service TemporaRily Unavailable (section for developers)
To correct the error 503, the developer should pay attention to the following:
Video Instructions Error Correction
In this material, I described what the 503 Service Temporarily Unavailable, listed the causes of this error and explained how to get rid of it. In most cases, this error concerns the problems of the functioning of the sites, and occurs for various reasons, from the banal overload of the site by external requests, and before activating the mailing script. If you are an ordinary user, and faced a similar problem, then I recommend simply wait, in most cases the problem is temporary and will disappear after a short time itself.
Internet users when entering sites meet the error 503 - Service Unavailable. This code appears on sites running on all popular CMS (Content Manage Service), such as MySQL, Joomla, DataLife Engine, Wordpress, etc. Therefore, let's figure it out, which means a 503 error.
What it is?
Error code 503 (Service Unavailable) - the temporary unavailability of the service. If we speak simple language - this is a kind of plug blank pagewhere the user gets.
Causes of such a problem:
- Connection errors with MySQL database or other CMS.
- Incorrect operation of plugins - they cease to perform the necessary functions or conflict with other plugins.
- Malaya bandwidth Site - Input queries more than the server processes (the limit of the simultaneous visit of users on the site is exceeded).
- Transmission (or processing) of large files on the server leads to the hang of the site scripts and slows down.
- Not an optimized automatic mail is taken by the server resources, thereby slowing it.
How to fix?
If you are an ordinary user, then you are not able to influence the error 503. The only solution is not to enter some time on the site until the administration eliminates the problem.
And if you are an administrator of the resource, analyze and trouble find a fault. Also contact your hosting company.
If your scripts work incorrectly or hang, do the following:
- Avoid requests with a remote server. If it is impossible to exclude, reduce the connecting timeout and make sure that the stable connection.
- Do not use scripts to transmit static large files by PHP - the operation may not be completed, since CMS components have a limited activity time. Configure direct file transfer.
- Try to start the mail newsletter at the time of the day when the load on the server is minimal (such as night - morning). Or perform the mailing manually.
- Optimize database requests. To do this, enable the caching feature.
Important! Do not neglect update scripts and CMS. The likelihood is that scripts different versions Start conflict with each other.
Also, the problem may be in a large number of appeals to the server. In this case:
If you have any questions. Perhaps together we will find a solution to the problem and tell me what to do.
