waterfall model pros and cons

receive traffic httpclient maximum, httpurlconnection and volley the same, okhttp slightly larger than the former two.5, the average time-consuming networkError description: The condition of the network may affect the network request time.Conclusion: The average time of network request is httpclient maximum, the httpurlconnection is the smallest, and the volley average is higher 10ms~20ms,okhttp than volley 20ms~40ms.The final conclusion is drawn:1 , for new applications, you should be more inc

, scalable.-Simple, weakly structured storage.-complex operations such as joins are weak.-Transaction support is weak.-Poor versatility.-Poor support for complex business scenarios without complete constraints.Although in the era of cloud computing, traditional database has a congenital disadvantage, but NoSQL database can not replace it, NoSQL can only be used as a supplement to the traditional data can not be replaced, so the disadvantage of avoiding the traditional database is the problem tha

of the Web.5.AJAX points of attention and applicable and non-applicable scenarios(1). Attention PointWhen Ajax is developed, network latency-that is, the interval between a user sending a request to a server to make a response-requires careful consideration. Not giving users a clear response, without proper pre-reading data, or improper handling of XMLHttpRequest, will make users feel delayed, which users do not want to see, but they do not understand. A common solution is to use a visual compo

most widely used are Sybase 10 and syabse for SCO Unix.Features of the Sybase database:(1) It is a database based on the client/server architecture.(2) It is a truly open database.(3) It is a high-performance database.5.db2DB2 is a database management system embedded in IBM's AS/400 system, supported directly by the hardware. It supports the standard SQL language and has a gateway connected to heterogeneous databases. Therefore, it has the advantages of fast speed and good reliability. However,

the user can already see the interface. Can be very good to prevent the interface is too complex to cause the black screen time is too long, but this is only a way to improve the user experience, to root or optimize the interface. The data is then asynchronously loaded. Finally, there is a handler used by the small strategy, when the data is more than the time can be appropriate to delay the handler send, for example, can call handler.sendemptymessagedelayed, set a delay time.Six, the network a

Factory mode is a design pattern of creation, it accepts the instruction, creates the instance which conforms to the requirement, it mainly solves the unified distribution of the resources, the creation of the object is completely independent, so that the object creation and the specific use of the customer is irrelevant. Main application in multi-database selection, class library file loading and so on.　　　The strategy mode is to solve the policy switching and extension, more concise is to defi

software platform. Capable of supporting up to 50,000 concurrent connections, thanks to Nginx for choosing Epoll and Kqueue as the development model.Nginx as a Load Balancer server: Nginx can either directly support the internal Rails and PHP programs outside the service, also can support as an HTTP proxy server external services. Nginx is written in C, which is much better than Perlbal, both in terms of system resource overhead and CPU efficiency.2, Nginx configuration is concise, Apache compl

distribution that's right for your desktop, and if you don't want to customize anything yourself, and you don't want to waste too much time on your system, it's easy, You choose according to your hobby in Ubuntu, Kubuntu and Xubuntu, the difference of the three is only the desktop program is different.If you need a server system, and you are very tired of the various Linux configuration, just want a more stable server system, then your best choice is CentOS, after the installation, after a simp

For the development of new software systems, object-oriented programming is undoubtedly the most widely used programming mode today. Because of the persistence demand of business data, relational database management system (RDBMS) has been widely used. An RDBMS uses a relational model, which differs from the domain object model in a software system. When developing software systems using object-oriented pro

In this article we will look at what is python threads and processes。 Learn about Python threads and processes, and learn about python threads and processes the Differenceand merits. We have introduced multi-process and multi-threading, which are the two most common ways to achieve multitasking. Now, let's discuss the pros and cons of both approaches. First, to achieve multitasking, we typically design the

the requirements.Does not have the built-in column number Ajax,route and other functions to the core package, but the plug-in way to load.The Mixins feature is supported in component development.Different points:React relies on the virtual DOM, and Vue.js uses a DOM template. The virtual DOM used by react will perform a dirty check on the rendered results.Vue.js provides instructions, filters, and so on in the template, which makes it easy and quick to manipulate the DOM.How do I use vue.js?1.

construct a certain degree of layout, easy to reuse the template, the data operation layer is good encapsulation, and codeigniter not use many too complex design patterns, Good execution performance and code readability. As for the additional library is also good, concise and efficient.Lavarel FrameAdvantagesLaravel's design idea is very advanced, very suitable for the application of various development models TDD, DDD and BDD, as a framework, it is ready for everything, composer is a PHP futur

the blacklist.Explain the above URL, "posts": it is generally referred to as the controller, which determines which processing file to load; "index": it is generally called an action, which determines what to do. So/posts/index/as the name implies is posts homepage. If you need to pass parameters later, you can add them directly behind the action.As in the following url:http://www.nostop.org/index.php/posts/category/1/. Lists all content under the category ID of posts 1.Some of the frameworks i