java performance tuning and optimization

Directory The usual string concatenation method written in the preceding It 's written in front . This is a very basic article that will show you how to use Java to correctly and efficiently stitch strings.These issues are also the basis of our attention to the performance optimization techniques. the normal string concatenation method uses the '+' operator to

Cache Size| Query_cache_type | On | cache type, determines what queries are cached| Query_cache_wlock_invalidate | OFF | when other clients are writing to the MyISAM table If the query cache is returned , the cache result, or wait for the write operation to complete the reread table to get results+------------------------------+---------+Mysql> show global Status Like "qcache%";+-------------------------+-------+| variable_name | Value |+-----------------------

Course ObjectivesProficiency in high concurrency architecture Tomcat Server performance optimization.Applicable peopleFriends interested in computer, Java Developer, Java Architect, OPS!Course IntroductionTomcat is a core project of the Apache Software Foundation (Apache Software Foundation) Jakarta Project, developed by Apache, Sun, and other companies and indiv

SQL turning is a tool in the Quest Central software produced by Quest Corporation. Quest is an integrated, graphical, Cross-platform database management solution that can manage Oracle, DB2, and SQL Server databases simultaneously. Introduction to SQL tuning for SQL Server The optimization of SQL statements is critical to the best performance of the databa

Note: This article is the third of our series of PHP performance analysis, click here to read PHP performance analysis first: Xhprof Xhgui Introduction, or PHP performance analysis second: In-depth study of Xhgui.In the first chapter of this series, we introduced Xhprof. In the second chapter, we studied the Xhgui UI, and now the last one, let's use Xhprof/xhgui

++){ byte[] Rowkey = Bytes.tobytes (Randomstringutils.random (8,"abcdesssss")); byte[] value = Bytes.tobytes (Randomstringutils.random (Ten,"Iojkjhhjnnbghikklm")); Put put=NewPut (Rowkey); Put.add (Bytes.tobytes (FAMILY_CF), Bytes.tobytes ("value"), value); Puts.add (Put); if(i%10000==0) {table.put (puts); Table.flushcommits (); Puts.clear (); }}3.3. Self-Added columnsDesttable.incrementcolumnvalue (Rowkey, Bytes.tobytes (FAMILY_CF), Bytes.tobytes ("testincrement "), Long.parselo

} If called directly, int i = 0;...Callmethod (i); It would be better to write: int i = 0;...if (i ==0) {Callmethod (i);} Without affecting the readability and so on, several small methods can be synthesized into a large method. 2. final,private, static keyword Adding final,private and Static keywords to the methods and variables is beneficial to compiler optimization. The Java compiler looks for o

: full GC takes a long time , the analysis of the system refers to the discovery, newratio=9, that is, the Cenozoic and Laosheng generation size ratio of 1:9, which is the cause of the problem:1, the Cenozoic is too small, causing the object to advance into the old age, triggering the old era of full GC;2, the old age is larger, the full GC is time-consuming;The optimization method is to adjust the value of the Newratio, adjusted to 4, found that the

Framework Official Guide Series 52--topic: Performance Tuning Summary: The performance of a network application is affected by many factors. Database access, file system operations, network bandwidth, and so on are all potential factors. Yii has reduced the performance impact of the framework in all aspects. But in t

The topics in this chapter are as follows: General performance tuning process Analyze page loading information using analysis tools Analyze performance bottlenecks using analysis tools General performance tuning process Before solving the

the increase of the server is again used, on the above loaded with Lucene, the database needs to query the data, submitted to Lucene, search all put into Lucene to do, the specific here does not trace back, Interested can find the relevant information here (invalid link).After the second step, the performance is improved to a new stage. Inaccessible, access errors or slow access are rare.But the optimization