page size
------------ + (round-trip time x alternate turns) + server process time + client process time = page response time
minimum bandwidth
1. Page size:
It is measured in Kbytes. There are many ways to determine the size of a web page.
2. Minimum bandwidth:
The minimum bandwidth between the server and the client is defined as the bandwidth of the smallest pipe between your website capacity and the user terminal. Once you know the page size and minimum bandwidth, you can calculate the initial download time:
Page size (kbytes)
DT= ---------------------------
Minimum bandwidth (kbytes/sec)
3. Round-trip time:
In web page response time, the round trip time (RTT) indicates the waiting period or time interval between the request from the client browser to the web server and the receipt of the first few bytes of data from the client from the web server.
RTT is an important metric because every request/response pair (even a small file) will incur a minimal performance penalty.
4. Take turns alternately:
Usually a web page is composed of a basic page and some additional objects, such as pictures or applets. These objects do not transition with the base page; instead, the base page HTML contains instructions to find and read them. Unfortunately for end-user performance, reading each object requires a reasonable number of additional communication cycles between the client system and the web server, and each object will experience some RTT latency.
Round-robin is defined as the number of TCP connections required to fully download a page. For HTTP 1.0, the minimum number of turns required to download a base page is 4. One rotation requires a DNS lookup (resolving the URL into an IP address), three rotations to request and receive the base page, and at least 3 rotations for each different object in the web page (if the object is processed by another server, an additional DNS lookups, which in this case mostly happen on the headline ad server).
5. Process time:
The last factor in the response time formula is the process time required by both the server and the client. so that it can be viewed by the requesting party. Different types of web pages can vary widely. On the server side, static pages of web pages require very little processing time, even negligible extra latency.
Dynamic pages require some server strength and computing time, and will also introduce some latency.
Finally, complex transactional pages can require huge processing time, possibly introducing more time delays. On the client side, the process time may be negligible by the end. If the page contains Java applets, for example, the client browser has to load and run the Java interpreter, it will take some time.
By learning this formula, you can easily take a partial approach to refine your web page response time.
E.g:
To keep the entire page size, you can bias the entire formula where you want. Since conversion rates can be significantly different between low-bandwidth and high-bandwidth clients, small page sizes will incur losses for low-bandwidth clients. Remember that the performance difference between a 40K and an 80K page is only a few ten thousandths of a second for a DSL/T1 client, but only 20 seconds for a 28k modem client.
Even if your page is very small and contains very few objects, if the server is not handling the load, your response time will drop dramatically. Your maximum load time is when your pages are best visualized and in business state, so don't forget to make sure your system can handle it without crashing and transitioning into a crash ----- make sure you can post, refactor, or Perform a load test before installing new hardware.
The final recommendation is:
Minimize the use of applets and other techniques that require reasonable traffic from the client process, so this may cause some performance impact to slow down the system. Because this delay is on the client side, you can't avoid it, because the law of responsibility will remind you over and over again: low performance will always be your fault. Luckily, backtesting is often true: a positive factor in your website is that users will give you enough trust—remember these common-sense principles, and you'll do more with less.