aed tuning

JVM tuning-New Generation and jvm tuning New Generation A new generation of Java virtual machines, including eden space and two dedicated vor spaces. The new generation is used to store newly created objects. The new generation features fast object updates and produces a large number of "Dead objects" in a short time ". Garbage collection for young generations is called secondary garbage collection (minor

JVM tuning series: garbage collection and jvm Tuning Summary: jvm is a required series, which summarizes some common jvm collection mechanisms for easy reference. Before optimization, we must understand how it runs. java's Garbage Collection is usually called "GC", which was born in The Lisp Language of MIT in 1960, after more than half a century, it has become very mature. Therefore, this article focuses

Jdk1.6 VM tuning practices (1) and jdk1.6vm tuning practices Linux 2 CPU 16 GB memory, tomcat7 JAVA_OPTS = "-Xmx1024m-Xms1024m-Xss1024K-XX: PermSize = 512 m-XX: MaxPermSize = 1024 m"Cygwin = false Heap memory: Xmx, xms is up to 1/4 of the physical memory size, which saves xms and xmx allocation. Xss, single thread Permsize: permanent partition size, Maxpermsize: up to 1/4 of the physical memory size

JVM tuning summary, jvm Tuning Heap size settingsThe maximum heap size in JVM has three restrictions: the data model (32-BT or 64-bit) of the relevant operating system; the available virtual memory limit of the system; and the available physical memory limit of the system. Generally, 32-bit systems are limited to Gbps ~ 2 GB; 64 indicates that the operating system has unlimited memory. In Windows Server

Chapter 9 JVM tuning recommendations and chapter 9 JVM tuning recommendations Note: This article mainly references distributed Java applications: basics and practices 1. JVM optimization is mainly about memory optimization, mainly in two aspects: Size of each generation Garbage Collector Selection 2. Size of each generation Common Adjustment Parameters -Xmx -Xms -Xmn -XX: Invalid vorra

JVM Tuning Tool Jconsole,jprofile,visualvm JCONSOLE:JDK, the function is simple, but can be used in a certain load of the system. The garbage collection algorithm is tracked in detail. Detailed description Reference here Jprofiler: Commercial software, you need to pay. function is powerful. Detailed description Reference here VISUALVM:JDK, powerful, similar to Jprofiler. Recommended. How to Tune Observe memory release, collection class checking,

:37YesOrchid Island Main 15:34:51Oh.Orchid Island Main 15:35:12Other, not quite understand your data in the situation, not very good fine optimization.Orchid Island Main 15:35:44Should still be quick.Snow Leopard 15:36:34GoodSnow Leopard 15:36:36Let me seeOrchid Island Main 15:37:16For example: The index of the other two tablesSnow Leopard 15:37:31WellOrchid Island Main 15:37:43The full table scan, although the table is small, but to 0.5s, should also be a small proportion.Snow Leopard 15:37:55I

inner table size is multiplied by the number of parallel service processes greater than the physical size.3) Pq_distribute (Tab_name, none,broadcast): This combination forces all data rows within the table to be broadcast to each consuming parallel query service process, while the outer data rows are randomly partitioned. This hint is recommended when the inner table is more than the outside hour. An important principle is that the none/broadcase hint is recommended when the inner table size is

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 |+-----------------------

can avoid Key lookup is perfect, let's revise non-clustered index to include it in the index with the Include keyword His fields are:[SQL] DROP INDEX idx_non_clust_salesorddetaildemo_modifieddate on salesorddetaildemo GO CREATE nonclustered INDEX idx_non_clust_salesorddetaildemo_modifieddate on salesorddetaildemo (ModifiedDate) INCLUDE ( ProductID, UnitPrice ) GO --Clear the cache, only for the development environment! DBCC Freeproccache DBCC dropcleanbuffers GO

Tags: establishing operations common Invalid database index characters NULL join exist Establish an appropriate index (refer to "pose for proper database indexing") Replace or with union (for indexed columns) Replace in, not exist with exist, not Do not declare numbers in character format (invalidates the index, resulting in a full table scan) Do not use SELECT * (List each column after select) Do not perform calculations in join and WHERE clauses (t

in 10g, Oracle launched its own SQL optimization aids : SQL Optimizer (SQL Tuning Advisor :STA) , it is the new Dbms_sqltune package. Use the STA to make sure that the optimizer is in CBO mode. but I think the use of such tools, only for the people who do not understand the tuning of SQL, do not feel that the tool can solve the problem. SQL says exactly what is expressed is a business, how the tool can und

Http://www.360doc.com/content/14/1208/13/16070877_431273418.shtmlUse JMeter to stress test tomcat and Tomcat performance tuningNginxtomcat Throughput Research ReportHttp://wenku.baidu.com/link?url= Fmp1sd8qbi87s23kei5nbek7mpjr-mwbte-pb4bn4iyqn1vqoagkig7bbnn5csmryhye4skxyoc5emjukc1gwqxnbgxsvrthadaxbcannf3Http://www.open-open.com/lib/view/open1401931407228.htmlIntroduction to JMeter's articlesHttp://www.cnblogs.com/TankXiao/p/4045439.htmlView JMeter Aggregation Tree ResultsTuning Series-tomcat

FineReport performance tuning methods, finereport Performance TuningThe basic idea of FineReport performance optimization is to properly set the memory size of the application server. Generally, the default memory configuration of the server is relatively small. In larger application projects, this memory is not enough. Therefore, you need to increase the memory size during processing. The memory configuration methods for each application server are d

First, diagnostic tools 1. Warning Log file Warning log files contain system information and error logs that contain important errors (such as: ORA-600) and block checksum error messages (ora-1578,ora-1498). Monitor database operations such as CREATE DATABASE, STARTUP, SHUTDOWN, ARCHIVE log, and RECOVER, and record Non-default initialization parameter values. When Log_checkpionts_to_alert is set to true, the warning log file also records the start and end times of checkpoints, incomplete checkpo

GIS image cutting performance tuning and GIS image Performance TuningStatus Quo and objectives DellR920 Server, virtualized vmware vsphere 5.5 system, Guest System Windows Server 2012 R2. Deploy software ARCGIS 10. Image graph cutting test: the original cut takes 70 hours, And now it takes 17 hours. There is still room for further optimization. Debugging objectives: 1. Verify the optimal graph cutting parameter configuration in the virtualization env

timeout; b read timeout; c write timeout);2.2. Parallelization of the serial request;A) use of curl_multi_* ();b) Use the swoole extension. 3. compress the PHP interface output:Using gzip compressionBenefits: Facilitates faster reception of data by client side;Cons: Extra CPU overhead 4. Cache Duplicate content: multiple requests, the content is not changed under the circumstances; 5.smarty Tuning and time window overlap ideas (which can be used in c

Performance optimization is to improve the system performance, reduce energy usage, or reduce the impact of applications on other parts. If the optimization is hasty or there is no measurement, of course, performance optimization may have a bad effect. Performance optimization is to improve the system performance, reduce energy usage, or reduce the impact of applications on other parts. If the optimization is hasty or there is no measurement, of course, performance optimization may have a bad e

In the case of performance problems with Oracle databases, it is less effort to use Oracle's own toolkit to give reasonable tuning recommendations.Tuning Advisor is optimized for the execution plan of the input SQL setThe Accsee Advisor is a recommendation on how much performance is improved if SQL set is introduced into an index or partition at this moment.SQL Tuning Advisor is a suggestion from the one ha

A basic knowledge1.1 What is performanceBefore performance tuning, let's start by understanding what performance is. With regard to performance, I think everyone who has studied Java can list a few points and even talk about it. In the Java TM Platform performance, the following five aspects are defined as criteria for judging performance:1) The performance of the operation--which algorithm performs the best performance?2) Memory allocation-How much m