diff --git a/docs/guide/performance.md b/docs/guide/performance.md index e69de29..a480a0b 100644 --- a/docs/guide/performance.md +++ b/docs/guide/performance.md @@ -0,0 +1,100 @@ +Performance Tuning +================== + +Application performance consists of two parts. First is the framework performance +and the second is the application itself. Yii has a pretty low performance impact +on your application out of the box and can be fine-tuned further for production +environment. As for the application, we'll provide some of the best practices +along with examples on how to apply them to Yii. + +Preparing framework for production +---------------------------------- + +### Disabling Debug Mode + +First thing you should do before deploying your application to production environment +is to disable debug mode. A Yii application runs in debug mode if the constant +`YII_DEBUG` is defined as `true` in `index.php`. Debug mode is useful during +development stage, but it would impact performance because some components +cause extra burden in debug mode. For example, the message logger may record +additional debug information for every message being logged. + +### Enabling PHP opcode cache + +Enabling the PHP opcode cache improves any PHP application performance and lowers +memory usage. Yii is no exception. It was tested with APC extension that caches +and optimizes PHP intermediate code and avoids the time spent in parsing PHP +scripts for every incoming request. + +### Turning on ActiveRecord database schema caching + +If the application is using Active Record, we should turn on the schema caching +to save the time of parsing database schema. This can be done by setting the +`Connection::enableSchemaCache` property to be `true` via application configuration +`protected/config/main.php`: + +```php + +``` + +### Combining and Minimizing Assets + + +### Using better storage for sessions + +By default PHP uses plain files to handle sessions. It is OK for development and +small projects but when it comes to handling concurrent requests it's better to +switch to another storage such as database. You can do so by configuring your +application via `protected/config/main.php`: + + +```php +``` + + +Improving application +--------------------- + +### Using Caching Techniques + +As described in the Caching section, Yii provides several caching solutions that +may improve the performance of a Web application significantly. If the generation +of some data takes long time, we can use the data caching approach to reduce the +data generation frequency; If a portion of page remains relatively static, we +can use the fragment caching approach to reduce its rendering frequency; +If a whole page remains relative static, we can use the page caching approach to +save the rendering cost for the whole page. + + +### Database Optimization + +Fetching data from database is often the main performance bottleneck in +a Web application. Although using caching may alleviate the performance hit, +it does not fully solve the problem. When the database contains enormous data +and the cached data is invalid, fetching the latest data could be prohibitively +expensive without proper database and query design. + +Design index wisely in a database. Indexing can make SELECT queries much faster, +but it may slow down INSERT, UPDATE or DELETE queries. + +For complex queries, it is recommended to create a database view for it instead +of issuing the queries inside the PHP code and asking DBMS to parse them repetitively. + +Do not overuse Active Record. Although Active Record is good at modelling data +in an OOP fashion, it actually degrades performance due to the fact that it needs +to create one or several objects to represent each row of query result. For data +intensive applications, using DAO or database APIs at lower level could be +a better choice. + +Last but not least, use LIMIT in your SELECT queries. This avoids fetching +overwhelming data from database and exhausting the memory allocated to PHP. + +### Using asArray + +### Processing data in background + +In order to respond to user requests faster you can process heavy parts of the +request later if there's no need for immediate response. + +- Cron jobs + console. +- queues + handlers. \ No newline at end of file diff --git a/docs/guide/template.md b/docs/guide/template.md index e69de29..dc83d15 100644 --- a/docs/guide/template.md +++ b/docs/guide/template.md @@ -0,0 +1,3 @@ +Template +======== +