Introduction to Programming for Performance in Microsoft Dynamics WHITEPAPER

Transcription

1 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics WHITEPAPER

2 Junctin Slutins dcumentatin 2012 All material cntained in this dcumentatin is prprietary and cnfidential t Junctin Slutins, Inc and subject t the nndisclsure prvisins f the applicable Junctin Slutins, Inc agreement. This material is fr infrmatinal purpses nly. Junctin Slutins, Inc is nt liable fr any damages in cnnectin with the use f this infrmatin. N part f this dcumentatin may be reprduced, stred in a retrieval system, r transmitted in any frm r by any means, including, but nt limited t, electrnic, graphic, mechanical, phtcpying, recrding, r therwise withut the prir written permissin f Junctin Slutins, Inc. This dcumentatin is subject t change withut ntice, and Junctin Slutins, Inc des nt warrant that the material cntained in this dcumentatin is free f errrs. Any errrs fund in this dcument shuld be reprted t Junctin Slutins, Inc in writing. Prprietary and Cnfidential Page 2 f Subject t Change

3 INTRODUCTION...4 RESOURCES...4 AREAS THAT AFFECT PERFORMANCE...4 SYSTEM OF RECORD...5 INDEXES IN MICROSOFT DYNAMICS AX...6 DATABASE MAINTENANCE...7 DO S AND DON TS...7 TOOLS FOR UNDERSTANDING PERFORMANCE Prprietary and Cnfidential Page 3 f Subject t Change

4 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Intrductin This is the first article in a series f articles and webinars cvering perfrmance in Micrsft Dynamics AX. The perfrmance f an enterprise applicatin is a key factr in hw users perceive that applicatin. There are many things that can be dne as a SQL administratr, systems administratr, r prgrammer t imprve the perfrmance f mdificatins in Micrsft Dynamics AX. Perfrmance shuld be cnsidered when designing, develping, and maintaining mdificatins in Micrsft Dynamics AX. Acceptable perfrmance levels shuld be set fr critical peratins, and shuld be maintained with an understanding f the cst f that maintenance. If users are cmplaining abut slw perfrmance cllect infrmatin abut perfrmance issues including reprductin steps, number f recrds, acceptable excitatin times, current executin times, and number f times the prcess is perfrmed. Resurces There are many resurces available t help understand perfrmance in Micrsft Dynamics AX including: Dynamics AX Perfrmance Team Blg blg frm the Micrsft team. MSDN Best Practices: Perfrmance Optimizatins - page n ptimizing Dynamics AX fr perfrmance Areas that affect perfrmance Perfrmance issues can riginate frm many places including: disk, ram, netwrk, memry, settings, prgramming, SQL, and the cmplexity f the prcess in questin. A system will generally perfrm as well as its weakest cmpnent, and it is imprtant t understand hw these cncepts wrk tgether when diagnsing a perfrmance issues. The fllwing list gives a brief descriptin f these cmpnents and hw they affect perfrmance. Disk Disks prvide the lng term strage medium fr a system, similar t a file cabinet hlding all f the paper recrds fr a cmpany. With Micrsft Dynamics AX, the area where disks affect perfrmance the mst is n the database server hlding the data files. Advanced technlgies are used t increase the perfrmance f these disks including: Strage Area Netwrks (SAN), Redundant Prprietary and Cnfidential Page 4 f Subject t Change

5 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Array f Inexpensive Disks (RAID), high speed hard drives, Slid State Drives (SSD), and mre. RAM Randm Access Memry is the shrt term wrkspace fr a system, similar t having files pen n yur desk. RAM becmes a perfrmance issue when there is nt enugh f it t adequately serve the system. Fr mst servers suffering perfrmance issues, a simple check t see if there is sme ram available is enugh t identify lack f ram as a perfrmance bttleneck. This is nt the case fr SQL Server. By default SQL Server uses all f the available ram in the system t stre data. Whenever a page f data is needed, SQL Server first checks t see if the requested page is in ram. If it is nt in ram, it will be retrieved frm disk int ram and used there. High disk utilizatin and lw buffer cache hit ratis are a cuple f examples useful in determining if there is enugh ram t adequately serve SQL Server. Netwrk All f the servers in a Micrsft Dynamics AX envirnment shuld be in the same lcal area netwrk (LAN) and ideally be n the same gigabit switch. The Micrsft Dynamics AX client shuld perfrm well when it is placed n the same LAN as the Micrsft Dynamics AX servers. If the client is in a remte lcatin (in a Wide Area Netwrk (WAN)) a technlgy similar t Terminal Server shuld be used t access the client. Settings There are many settings that can affect perfrmance including: Maximum degree f parallelism, trace flags, SQL trace, and debugging. Prgramming Writing cde is like writing in English. There are many ways t cmmunicate the same cncept, and sme f them are better r mre efficient than thers. SQL When researching perfrmance issues many times the cre f the issue is an inefficient SQL statement. A pr perfrming SQL statement can be tuned by rewriting the cde and adding indexes. Cmplex prcesses Cmplex prcesses take mre effrt t prcess than simple nes. When creating a mdificatin it is imprtant t weigh the cst f this mdificatin. When analyzing the cst, be sure t include develpment time, test time, cde merge time in upgrade, supprtability, and the perfrmance cst f a mdificatin. System f Recrd The Applicatin Object Tree (AOT) in Micrsft Dynamics AX is the wner f the database schema fr Micrsft Dynamics AX nt SQL Server. Any changes t tables in the database schema need t riginate in the AOT. The synchrnizatin prcess will Prprietary and Cnfidential Page 5 f Subject t Change

6 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics then mve these changes t SQL Server. If changes t a table such as adding an index are perfrmed in SQL Server directly, the synchrnizatin prcess will fail the next time it is run. Indexes in Micrsft Dynamics AX An index makes it easier t find specific data frm a table. There are three main types f indexes used by Micrsft Dynamics AX: primary, clustered, and nn-clustered. Primary Index: A primary index prvides a unique key t each recrd in a table. This index is the ne used fr recrd caching in Micrsft Dynamics AX. Clustered Index: A clustered index rganizes the data fr a table in the rder f the index. A phne bk is a gd example f a clustered index. The data in a phne bk is first srted by last name and then by first name. Fr each last and first name listed in the phne bk there is a crrespnding phne number and address. The data fr a table can nly be rganized ne way and therefre there can nly be ne clustered index. Nn-Clustered Index: A nn-clustered index prvides a way t quickly reference data fund in the clustered index r heap (table withut a clustered index) using a specified set f clumns. An example f a nn-clustered index is the index at the back f a text bk. Yu can lk up the tpic yu want, and the index prvides a list f page numbers which have infrmatin n that tpic. Fr example, yu culd add a phne number index t a phne bk s yu culd mre quickly find an address by searching fr a phne number. With this index yu culd lk up a phne number. This wuld prvide a last name and first name (the key clumns fr the clustered index). Next, yu can use these t lk up the address. This prcess invlves a secnd lk up, but is much faster than lking at every phne number in the phne bk and cmparing with the ne yu are lking fr, which is the alternative and knwn as a table scan. The rder f the clumns in an index is very imprtant. Fr efficiency, an index shuld be rganized frm the mst granular clumn (highest number f unique values) t the least granular clumn with each clumn having data in a where clause. Using the phne bk example again, it is easy t find all f the peple in Denver with the last name Dragn, but wuld be incredibly difficult t find thse with the first name Chris, because the phne bk is rganized by last name and then first name. Als, if the phne bk were rganized by first name and then last name, it wuld take less time t find Chris but mre time t find the name Chris Dragn, because there are mre peple in the phne bk with the first name Chris than there are with the last name f Dragn. Prprietary and Cnfidential Page 6 f Subject t Change

7 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Imprtant: By default Micrsft Dynamics AX adds DataAreaId as the first clumn in an index, and adds DataAreaId t each query frm Dynamics AX. Als, if a query is being made directly against the database make sure DataAreaId is included in the where clause fr each table. If DataAreaId is nt included in the where clause f a query made directly against the database, indexes will nt be used, table scans will be perfrmed, and perfrmance will suffer. The fllwing index best practices shuld be fllwed: Always maintain indexes in the AOT Always specify a clustered index Always specify a primary index A RecId index is a gd candidate fr the primary index if the clustered index is nt set t unique Limit the number f clumns in an index, especially if it is a clustered r primary index Indexes n integers, r enums are better than thse n strings, and indexes n small strings are better than thse n large strings D nt create duplicate indexes D nt create left key subset indexes. If ne index is cntained in the same rder as the left (first clumns) in anther index is it nt useful. Fr example if there is an index n the phne bk n last name, and anther ne n last name then first name. The ne cntaining nly last name des nthing. Add an index if the speed gained by adding the index is greater than the cst f updating that index. The speed gained by adding an index needs t include bth the perfrmance imprvement f the query and the number f times it is executed Nte: NOTE: When a recrd is inserted r updated all indexes related t that table als need t be updated Database Maintenance As data is added and remved frm a table the indexes assciated with that table becme fragmented and therefre less efficient. A peridic prcess shuld be added t rebuild and rerganize indexes when they reach fragmentatin threshlds. D s and Dn ts The fllwing is a list f prgramming cncepts that shuld be understd t effectively develp fast mdificatins: Prprietary and Cnfidential Page 7 f Subject t Change

8 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Find the number f a type f recrd Descriptin: perfrm as much wrk as pssible in a single SQL statement. Reducing the number f calls t the database even if they are mre cmplicated imprves perfrmance. Dn t: lp ver a set f recrds and use a cunter variable t cunt the results While select salesline where salesid == 123 { Cunter++; } D: use keywrds including cunt, avg, maxf, and minf. Select cunt(recid) frm salesline where salesid == 123 Lcatin f select filters Descriptin: sending data between the AOS and the database is slw, and shuld be avided. Perfrming a select which returns nly the data that is needed reduces unnecessary verhead. Dn t: perfrm data filters in an if after the select statement While select salesline { If (salesline.salesid == 123 ) D: perfrm all pssible data filters in the where clause f a select statement While select salesline where salesid == 123 Prprietary and Cnfidential Page 8 f Subject t Change

9 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Nested lps Descriptin: Perfrming a query in SQL server with a jin allws SQL t prcess this request nce, and fr it t send mre data t the AOS at ne time. Dn t: use unnecessary nested lps While select salestable { While select salesline where salestable.salesid == salesline.salesid D: use jins where pssible t lp thrugh recrds While select salesline jin salestable where salestable.salesid == salesline.salesid Lcatin f significant SQL calls Descriptin: Fr every SQL call made n the client that request needs t be sent client t AOS t SQL t AOS t client. If that request is made frm the AOS the request is sent AOS t SQL t AOS. Reducing these Remte Prcedure Calls (RPC) calls can have a significant effect n perfrmance. Nte: T call a prcess frm the server mve the cde t a class and change the run n prperty f the class t Server. Dn t: Call cmplex prcesses with multiple SQL calls frm the client. D: Call cmplex prcesses with multiple SQL calls frm the AOS. Prprietary and Cnfidential Page 9 f Subject t Change

10 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Cursr versus set based peratins Descriptin: Using set based peratins reduces the cmmunicatin between servers required t accmplish a task. Prgramming with set based peratrs can be mre difficult than using cursr (recrd by recrd) based peratins, thugh the perfrmance imprvement can be dramatic. Additinally, if the insert, update, r delete methd are verridden insert_recrdset, recrdinsertlist, update_recrdset, r delete_frm will revert t cursr based updates. Dn t: Use while select and an insert, update, r delete statements when making changes t large numbers f recrds at nce when pssible. D: Use insert_recrdset, recrdinsertlist, update_recrdset, and delete_frm when making changes t large numbers f recrds at nce. Transactin blcks Descriptin: A transactin blck grups database mdificatins tgether s that if ne fails the related mdificatins als fail. This is a gd thing that preserves data integrity. At the same time the prcess f hlding these recrds s they all cmmit t the database at the same time lcks these recrds s ther prcesses can t update these recrds. If a significant number fr recrds is being mdified these lcks can escalate t table level lcks which prevent any transactin frm ccurring n the lcked table until the transactin has cmmitted. Transactin blcks shuld be big enugh t preserve data integrity while being small enugh t allw adequate perfrmance f the system. Additinally n user interactin shuld ever be placed in a transactin blck, because then ther prcesses have t wait fr a user t respnd (users respnd slwly) befre they can access the data they need. Dn t: lck recrds fr an extended perid f time with large transactin blcks Dn t: put any user interactin in a transactin blck D: limit the size f transactin blcks where pssible Prprietary and Cnfidential Page 10 f Subject t Change

11 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Cached display methds Descriptin: Display methds are called many times fr a single recrd as a user interacts with the frm that display methd is n. If the display methd is cached, then the lgic behind this display methd is called nly nce. D: when pssible cache display methds Filter using * Descriptin: Even if there is an index n the sales rder id field it will nt be used if the search string entered is *123. This search is similar t trying t find all f the last name Dragn in the phne bk by lking at all f the last names that end in ragn. The nly way t d this is t lk at every last name in the phne bk. Dn t: Train end users t search fr the sales rder s by entering *123. D: Train end users t search fr the sales rder s by entering SO Temprary table usage Descriptin: In memry temprary tables are respnsive and effective fr small data sets. When a temprary table exceeds 128 kb the table is mved frm memry t disk, and it becmes extremely slw. Micrsft Dynamics AX 2012 features a new type f temprary table TempDB which addresses this size limitatin, but these tables cannt be used n a frm. Dn t: Use in memry temprary tables with large number f recrds fr prcessing. D: Use in memry temprary tables fr small calculatins when apprpriate. Prprietary and Cnfidential Page 11 f Subject t Change

12 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Tls fr understanding perfrmance There are many tls available t understand and diagnse perfrmance issues in Micrsft Dynamics AX. This list will give a brief descriptin f these tls. Mre infrmatin will be given in later articles. PerfMn - This is a Windws tl which tracks perfrmance infrmatin. This can either be viewed real time, r tracked ver time using Data Cllectr Sets. Trace Cckpit (Trace Parser) In Micrsft Dynamics AX 2009 and 2012, a trace can be taken f any prcess. This trace includes all f the cde that executes fr the perid f time traced. The Trace Cckpit helps navigate the trace t find the areas f cde that run slwly. Perfrmance Analyzer The Perfrmance Analyzer is a SQL server based tl which captures key statistics n the database n a peridic basis and stres it in a database which can be queried later. The infrmatin cllected includes lng running queries, tables missing indexes, imprper clustered indexes, missing clustered indexes, and mre. Dynamics AX SQL Trace traces can be setup t shw the SQL statements that are executed. This infrmatin is helpful because it includes bth the SQL Prprietary and Cnfidential Page 12 f Subject t Change

13 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics statement that the database will execute, as well as the X++ call stack. SQL Server Prfiler captures a cnfigurable set f events frm SQL server. The events that can be captured can include useful infrmatin such as lgins, Prprietary and Cnfidential Page 13 f Subject t Change

14 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics lng running queries, lcks, and deadlcks. SQL Server Database Tuning Advisr (DTA) When given a lng running query DTA prduces a list f indexes and updates t statistics which wuld imprve perfrmance. The results f DTA shuld nt be directly implemented, but rather they can be used as a starting pint fr tuning a query. SQL Server Management Studi (SSMS) SSMS is the primary tl used t interact with the database. Sme f the tasks that can be perfrmed in SSMS in regard t tuning a query include: Prprietary and Cnfidential Page 14 f Subject t Change

15 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Run SQL statements T effectively tune a lng running query, the query needs t be brught int SSMS. Any parameters which the query uses must be filled in, and accurate executin times need t be fund. Include client statistics This ptin prduces an additinal tab with the results which capture key statistics like run time in millisecnds. Capturing accurate times is critical fr determining if index fixes are effective. Als, any query shuld be run multiple times s caching des nt affect the executin time f a query. Prprietary and Cnfidential Page 15 f Subject t Change

16 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Review executin plans The executin plan f a query is the radmap fr hw SQL server will internally prcess a query. SSMS can prvide an estimated r actual executin plan. The estimated plan des nt require the query t execute befre it is generated, s yu can access it faster, but the actual executin plan is mre accurate. Thrugh an executin plan a DBA can determine which parts f a query are slw, which helps t determine hw t fix the perfrmance issues. Prprietary and Cnfidential Page 16 f Subject t Change

17 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Read lgs Using SSMS a DBA can review the errr lgs fr SQL as well as the peratin system hsting SQL. Check settings Shw the settings such as max memry and maximum degree f parallelism that are set n the SQL Server. Prprietary and Cnfidential Page 17 f Subject t Change

18 Intrductin t Prgramming fr Perfrmance in Micrsft Dynamics Review Maintenance Plans Review the maintenance being perfrmed n a SQL server. Prprietary and Cnfidential Page 18 f Subject t Change