Solutions to large traffic and high concurrency of PHP websites

How does a PHP website cope with large traffic and high concurrency?

First, confirm whether the server hardware is sufficient to support the current traffic. Ordinary P4 servers can generally support up to 100,000 independent IPs per day. If the number of visits is greater than this, please configure a higher-performance dedicated server. , otherwise no amount of optimization can completely solve the performance problem.

Secondly, optimize database access. It is best to make the front desk completely static, and there is no need to access the database at all. However, for websites that are frequently updated, staticization often cannot meet certain functions. Caching technology stores dynamic data in cache files, and the ** pages directly call these files without having to access the database. Both WordPress and Z-Blog use this caching technology extensively. If access to the database cannot be avoided, you can try to optimize the query SQL of the database. Avoid using statements such as Select * from. Each query only returns the results you need, avoiding a large number of SQL queries in a short period of time.

Third, external hotlinking is prohibited. Hotlinking of pictures or files from external websites often brings a lot of load pressure. Therefore, external hotlinking of own pictures or files should be strictly restricted. Fortunately, hotlinking can be controlled simply through refer, and Apache itself can configure it. To prohibit hot links, IIS also has some third-party ISAPIs that can achieve the same function.

To prevent hotlinking by forging referrer codes, you can add a watermark to the image.

Fourth, control the download of large files. Downloading large files will consume a lot of traffic, and for non-SCSI hard drives, downloading a large number of files will consume the CPU and reduce the website's responsiveness. Therefore, try not to provide downloads of large files exceeding 2M. If you need to provide them, it is recommended to place the large files on another server.

Fifth, use different hosts to divert main traffic Place the files on different hosts and provide different images for users to download. For example, if you feel that RSS files take up a lot of traffic, then use services such as FeedBurner or FeedSky to place the RSS output on other hosts. In this way, most of the traffic pressure of other people's access will be concentrated on FeedBurner's host, and RSS will not occupy too many resources.

Sixth, use traffic analysis and statistics software. Installing a traffic analysis and statistics software on the website can instantly know where a lot of traffic is consumed and which pages need to be optimized. Therefore, accurate statistical analysis is required to solve the traffic problem. The traffic analysis and statistics software I recommend is Google Analytics. I feel that its effect is very good during use. Later I will introduce in detail some common sense and skills of using Google Analytics. .Sub-table 2.Separation of reading and writing 3. Front-end optimization. Nginx replaces Apache (front-end load balancing) The main thing is to see whether the distributed architecture is in place. The optimization of mysql and cache are limited optimizations. But once the distributed architecture is built, after the PV increases, only heap machines are needed to expand the capacity. Optimization experience: First of all, learn to use explain statements to analyze select statements and optimize indexes and table structures. Secondly, rationally use caches such as memcache to reduce the load of MySQL. Finally, try to use Facebook's hiphop-php to compile PHP to improve program efficiency.