Performance Test Metrics

Performance Test Metrics

General indicators (refer to Web application Server, database server required test items )

Web Server Metrics

Database Server performance Metrics

The bottleneck definition of the system

Stabilizing the resource state of the system

Popular Understanding:

• Daily Visit volume

• Maximum number of common page concurrency

• Simultaneous online headcount

• Access to the appropriate time

Case: A recent company project, is a portal, need to do performance testing, according to the characteristics of the project to set out the main test items and test plan:

One is to test the maximum number of concurrent numbers that can be accepted by several popular pages (user name parameterization, set point policy)

One is to test the server under long-time pressure, the user can operate normally (user name parameterization, Iteration run script)

One is to test whether the server can accept 100,000 of users at the same time online operation, if the use of IIS as an application server, the maximum number of concurrent single can not reach 100,000 levels, it is necessary to use the cluster, multi-machine load balancing to achieve , if the application server such as WebSphere, a single can withstand the maximum number of concurrent can reach 100,000 levels, but for performance considerations or must use the cluster, multi-machine load balancing to achieve, usually there are 1 simple calculation methods, 1 connections to generate 1 sessions, Each session on the server has a memory space size setting, on NT is 3M, then 100,000 concurrent need 300G memory, of course, the actual use of other programs also take up memory, so the amount of memory required to prepare more than this. There are 100,000 users online at the same time, with 100,000 concurrent numbers is a completely different 2 concepts. This upstairs has been said. But how does this conversion convert 100,000 simultaneous users to how many concurrent numbers? This has to be supported by a lot of historical log information. The system log needs to have the same number of online users of the log information, but also the number of user operations log information, the proportion of the 2 data is you at the same time the number of users online conversion to concurrency ratio. In addition, according to experience statistics, for 1 Java development of the web system (other I did not count, no data), generally 1 dual CPU, 2G memory of the server can support the maximum number of concurrent concurrency of 500 (in this state most operations are over-the-times error and the server is easy to downtime, In fact, there is no practical significance), can be used normally (single step non-large data volume operation wait time not more than 20 seconds) the maximum number of concurrent no more than 300. Assuming that your 100,000 simultaneous online user conversions are 9,000, then you need at least 18 units of this machine, not less than 30 units. Of course, if you buy a large server, which contains 200 CPUs, 256G of memory, gigabit fiber bandwidth, even 100,000 concurrent users, that speed, is definitely swish.

It takes nearly 6 hours for all light settings to enter the operating state. Concrete can take 1 system to press A look, may appear the following situation:

1, server downtime;

2, client downtime;

3, from a certain time to start the server refused the request, the client is full of errors displayed;

4, reluctantly test completed, but the network congestion or test results show a very long time. Suppose the client and server between the hundred gigabit bandwidth, hundred trillion/10000=10k, that each user can only get 10K, this speed nearly 1 64K modem internet speed, and the above analysis all did not consider the background of the system, such as database, middleware and so on.

Server aspects: The above said that the PC server needs 50 units;

Network aspects: According to each user 50K, that at least 5 hundred trillion bandwidth exclusive, estimated that only the network delay is about the second level;

If you have a database, or at least Oracle, it's best that Sysbase,sql server is definitely not up to the top. The database server requires at least 10 machines with 4CPU and 16G of memory;

If there is CORBA, then at least 10 sets of 4CPU, 16G memory of the machine, coupled with load balancing, firewalls, routers and a variety of software, in short, not a 10 million of the capital investment, it is certainly uncertain.

Such a portal system, because of the user rights, so not as Jackie said most of the static page. But as long as it is a multi-server cluster, we can calculate the load capacity of multiple machine clusters through the test results of 1 machines, with the additional consideration of load balancing and routing pressure, such as bandwidth, speed, latency, etc. But if all the changes in 1 machines, then we can only do some of the indicators on the calculation, can be easily judged from these indicators is not feasible, such as 100,000 concurrent users but only 1 hundred trillion bandwidth, then we can calculate the user only 1 K bandwidth, which is obviously not possible. But the actual results still need testing to know, after all, the system pressure and the number of users is not linear change.

The widespread use of this type of system, as well as the ability of many software to approximate the performance characteristics of the system after design, have led to a large proportion of the system's tuning in software performance (which certainly does not completely exclude further improvements in performance after some code and configuration optimizations), More of the hardware considerations, such as increased memory, hard disk raid, increase the bandwidth, and even increase the machine.

The 10M bandwidth in network technology refers to a bit calculation, that is 10M bit/second, and the speed of download is measured in bytes (byte), so 10M bandwidth conversion into bytes theoretically the fastest download speed: 1.25 M byte/seconds!

Performance Test Metrics