java performance tuning tips

Before finishing a Java Performance optimization blog, Link Java performance optimization One, today to add a few1. Take care of the cyclic traversal of JavaA list traversal in Java can be a lot more cumbersome than it looks. Take the following two code example: a: Priva

loss of responseC. Swap memory is used when physical memory is insufficient, and swap will bring disk I0 and CPU overheadD. Problems that can cause CPU bottlenecks: Frequent Perl,php,java programs generate dynamic web; database queries a large number of where clauses, order by/group by ordering ...E. Possible memory bottlenecks: High concurrent user access, system processes, Java memory leaks ...F. Possibl

the nature of the method, and calling this method does not change the state of the object.28. The use of intrinsic get,set methods should be avoided wherever possible.In Android programming, the invocation of a virtual method has a lot of cost, more than the cost of an instance property query. We should use the Get,set method when we outsource the call, but it should be called directly when it is called internally.29. Avoid enumeration, use of floating-point numbers.30. A two-D array consumes m

function-oriented table. This colleague is also a good practice because she tells you how to distinguish the nature of the method, and calling this method does not change the state of the object.28. The use of intrinsic get,set methods should be avoided wherever possible.In Android programming, the invocation of a virtual method has a lot of cost, more than the cost of an instance property query. We should use the Get,set method when we outsource the call, but it should be called directly when

problem.27. Consider using static methods,If you don't have to go to the outside of the object, make your method a static method. She will be called faster because she does not need a virtual function-oriented table. This colleague is also a good practice because she tells you how to distinguish the nature of the method, and calling this method does not change the state of the object.28. The use of intrinsic get,set methods should be avoided wherever possible.In Android programming, the invocat

, that is, the so-called "know each other, the victorious" principle.Purchase Address:http://www.china-pub.com/3501136Course Requirements 1. Have a strong interest in performance testing.2. Need a certain programming foundation, can read basic C language code can. But need to have certain self-study ability, this is the performance completes the performance test

used to control the process.4. Use local variables as much as possibleLocal variables, the parameters passed when the method is called, and the creation of temporary variables are saved in the stack (stack), faster, other variables into static variables, global variables are created in the heap (heap), slower.Extension: The stack is allocated by the system, faster, the stack uses a first-level cache, they are usually transferred to the storage space, the call is immediately released, the heap i

, connection pooling (C3P0, DBCP)11, Database data classification storageStore frequently accessed data and low-frequency data, respectively, into different partitions, or even to different database servers, in order to fit into the allocation of hard disk I/O and system I/O.12. Cache PolicyIf some data is to be read from the database frequently, and the data does not change frequently, the data can be cached in the system and read the cache directly, instead of frequently accessing the database

minute or two and then kill-3 PID again to check the changes in the threads of the wait for monitor, this is very important for the analysis of whether there is unreasonable competition for excessive locks in the analysis thread. This step is undoubtedly the most difficult step in the performance tuning process. The analysis of the system performance bottleneck

, connection pooling (C3P0, DBCP)11, Database data classification storageStore frequently-visited data and low-frequency data to separate partitions. Even to different database servers to allocate hard disk I/O and system I/O in a fit.12. Cache PolicySuppose that some data is often read from the database. At the same time, these data do not change very often, the data can be cached in the system, the use of the direct reading of the cache. Without frequent access to the database to read data.Cac

BEA WebLogic jrockit usage and Performance Tuning 1. Introduction to jrockit OptimizationJrockit is an adaptive JVM that can automatically adjust itself to adapt to the underlying hardware. Therefore, its optimization is mainly focused on parameters that require manual intervention, such: the number of Ram resources to be allocated to jrockit. Jrockit has a set of non-standard-x startup options that we can

there are many differences between 2.6 and 2.4, such as epoll support and NPTL adoption. epoll support is also very important for java, in the case of high concurrency, there is a big difference in whether nio uses epoll. The adoption of NPTL is extremely important for multithreaded programs. In addition, you need to pay attention to the File Handles, network buffer, MTU, and Memory Page size in linux. JVM There are many articles on JVM optimizati

Websphere? Application Server Performance Tuning Toolkit is an Eclipse-based smart tool designed to help users tune WebSphere application by using data collection, data analysis, and statistical inference techniques The performance of the Server. The goal is to help users find bottlenecks and tune applications appropriately.Background knowledgeWith the wide deplo

third-party applications running on Linux, there are many performance tuning techniques that can help you improve the performance of your Linux servers and lower your operating costs.14. Correct configuration of MySQLTo allocate more memory to MySQL, you can set the MySQL cache size, and if the MySQL server instance uses more memory, reduce the cache size and in

This article is the third of the GC expert series. In the first understanding of Java garbage Collection, we learned several different GC algorithm processing processes, the way GC works, the difference between the new generation and the old age. So, you should have known about the 5 GC types in JDK 7, and the performance impact of each GC.The second monitoring of Java