AS400性能调整.doc

AS400 Performance Turning 一、ConceptResponse Time1、Duration from press of button to the release of another inputJob States1、Activeexists in main storage and processes work requested by the application2、Waitneeds a resource that is not available3、Ineligiblethe system is unable to accept more work at that time.Wait States1、Short Waitholds an available activity level while waiting for an activity to occur. (ex. Sndbrkmsg, write) A job can remain in short wait for a maximum of 2 seconds. 2、 Long Waitjob leaves activity level. (ex. Key/think, record lock)3、Short Wait Extendedshort wait to long way transitionActivity Level1、Restricts the number of jobs in main storage at one time2、Assures the job system resourceIneligible Queue1、Not enough resources are available, jobs become ineligible2、It is placed in the ineligible queue until an activity level is available.3、Long wait state job normally FIFO4、Short wait extended or long wait caused by lock conflict it places in front of the queue.Process Access Groupthe variables and data in the application do not have the same values for all jobs using the application. These portions of the application and other unique objects are packaged as an object called a process access group and can be paged in or out in one operations.Time Slice1、Amount of processing unit time allowed for each transaction.2、If no jobs of equal or higher priority are on the ineligible queue, the job is given another time slice, remains in main storage, and continues the transaction.3、 Else, job move to ineligible queue or time slice end pool (*BASE)Purge (*Yes) / (*No) 清除“性能工具”的一个作业属性，指定当作业进入一个漫长等待或者离开活动层时，是否将一作业标志为可选来从主存储器移出至辅助存储器。1、Specify purge (*yes) in job class for most of the environment and system determine the efficiency of writing of PAG2、Purge (*no) may cause fewer writes reduce disk use less processing unit time more main storage Expert Cache (专家高速缓存) OS/400 操作系统的存储管理功能的扩充，它允许单级存储体系结构充分利用主存储器（高速缓存）的容量。二、Things which affect performance1、CPU2、Disk3、Memory4、I/O Controller5、Communications Bandwidth6、Bad Applications Error Handling Redundant Code No Share Resources7、Irregular System Activities Signoff Interactive Comply Opnqryf三、Step By Step Tuning1、 Set automatic and system defaults （Automatic Tuning）Set QPFRADJIt changes the machine pool size (QMCHPOOL)It changes a) Base activity level (QBASACTLVL)b) Share pools (*INTERACT, *SPOOL & *SHRPOOL 1-10)2、 If result is not satisfied, turn off automatic and manual set to an determined initial value（Manual Tuning）a、Use CHGSHRPOOL command parameterPAGING (*FIXED)限制在存储池运行的作业的内存使用数量。 PAGING (*CALC) 较多作业，限制内存的数量；内存足够，决定多少的数据进入存储池；送交频繁，则让大的数据块进入内存，以延迟交换数据的写，减少I/O操作，响应时间。b、Initial Machine Pool Sizea) 最小的Machine Pool=512*1024*0.07+1024k =37724K (假设内存为512M=512*1024K)b) JOB Space 4K for each active jobc) Communications Space125K each line100K each protocol25K each work station2617, 2618, 2619, 2665, 2666 1.5M and ignore 125K for line3600K for 1 port FSIOP and 5400K for 2 port d) Functional Space3270 50KSave / Restore 68KDBCS 50KX.25 48KToken Ring 250Ke) Disk Space4 - 64 disk drives64K per unit 64 disk drives20K per unitc、设置交互式作业a) Number of users divided by four for activity levelb) Storage 600K to 1000K for each activity leveld、Setting Up Batch Poola) Short Running 800K to 1750Kb) Long Running1250K to 3500Kc) Compiles12000K to 24000Kd) Sort1500K to 3000Ke) Queries1500K to 4000Kf) Save / Restore1000K to 3000Ke、Setting Up *Basea) Activity level should between 5 to 30b) 6M small system uses 5c) 512M large system uses 30f、Setting Up Spool Pool AFPNo. Of WriterStorageActivity Level115001217002319003421004423005g、Setting Up Spool Pool Non-AFPNo. Of WriterStorageActivity Level1801216023225342904435053、 Collect / analyze performance dataa) Observing System PerformanceMachine Pool fault rate 0.4 should decrease storage sizeNon-db Fault in machine poola) 15 is poorb) Sum of db & non-db fault per poolMachineGoodAcceptablePoor400, 500100500, 40S, 50S 175510, 530300530, 53S750c) Observe Job TransitionDivide Wait - Ineligible by Active-Wait .25 is poord) 硬盘的利用 保持70%以下的硬盘利用 硬盘繁忙率一般保持在50%以下，偶尔要70%以下4、Tuninga) Interactive TurningEnter command WRKSYSSTSSet assistance level to intermediate or advanceWait 2-5 minutes, press F5 to refreshb） Does non-db fault in machine meet the guidelineNO-则调整QMCHPOOL: -50K if fault rate = 0+50K if fault rate 3.0Press F10 to reset and go to the previous step YES- db & non-db faults 20 in any pool, then Increase pool size by 50K and reset statistics and refresh to monitor until it is within the guidelineIs wait to ineligible state = 0 ? then reduce activity level by 2 and repeat until it is 0.Is the active to wait 10x the activity level, 4、 Analyze and tune againPerformance Explorer 数据收集工具使用performance monitor 收集数据无法确认或者作一般性的分析无法确认性能问题的原因之后使用Performance Explorer。独立性能问题；模拟性能的应用。 报告功能和相关命令作为性能工具的一部分。1、 必须对performance issue 有很好的理解。需要更多的性能知识。2、 必须设置performance explorer在系统指定的区域收集数据，将不得不去说明解释数据。什么时候使用 当性能指导器不能告诉你更多的时候，也就是其他工具不行的时候。它收集许多详细的数据表格，很容易离析包括性能问题的要素。Explorer和advisorAdvisor只是对monitor收集来的数据作出一些结论，执行Advisor只是做一些常规的维护，而Explorer只是收集更详细的数据，不做结论。例子：一个反应迟缓的系统可能是由于：DASD的读写，或者CPU，或者是两者引起的。使用Explorer你就发现原因的。使用Explorer的好处：1、 在一个作业上作详细地分析而不影响系统上其他的操作。2、 不用在收集数据的系统上分析数据，可以发送到其他系统去分析。3、 可以绘制性能信息反馈给源代码，使性能数据和引起产生这些数据的代码关联起来。4、 在用户开发的软件上收集数据信息。但必须使性能收集可用，命令为CRTBNDC的ENBPFRCOL参数，或者CHGPGM的ENBPFRCOL参数。使用performance explorer:1、 go performan选择option5(performance utilities)选择option2(work with performance explorer)2、 定义所想收集数据，explorer将提供给3种数据收集类型：统计性，描述性，追踪文件。统计性数据：确认应用程序和IBM程序或者指令消耗过多的CPU资源或者执行过多的I/O操作。从而更深一步研究程序的性能瓶颈。指定*stats。两种组织：一是树形，而是列表性。描述性数据：确认高级语言程序的不断分叉引起的效率，如果程序足够大，而分叉不断持续且向前，则会引起受限主存的过多缺页率。追踪文件数据：收集性能活动的历史追踪文件。指定数据类型之后，会有很多喧响。Performance Explorer流程*查找已经活动的会话名 ENDPEX SSNID(*SELECT)*打印EXPORT命令 PRTPEXPRT*库 QAYPE*查看数据库文件RUNQRY 性能数据-用于调整提高响应时间和吞吐量的一套信息。Collection services STRPRFCOL不断收集少量不为人注意的性能数据，放在一个叫*MGTCOL的收集对象。CRTPRFDTA处理*MGTCOL，产生数据库文件。使用它去确认关于系统上不同区域使用系统资源的