12.09.2014, 12:11 | #1 |
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emeadaxsupport: Managing general performance issues in Microsoft Dynamics AX
Источник: http://blogs.msdn.com/b/axsupport/ar...namics-ax.aspx
============== This post is primarily aimed at non technical readers and those responsible for coordinating or managing these issues, but with links drilling through to more in depth blogs containing further details. By 'general performance', I mean a set of unidentified performance issues across one or more modules, or indeed the entire application. This is intended to provide a suggested approach drawing on experience, to get you started in what can be a challenging area. General performance issues can often be highly political and complex. Many organisations and groups within organisations may be involved due to the number of different potential factors and root causes; it can often be a combination of factors. There is often no clear error message or steps to reproduce each issue consistently and the issue itself may not be clearly defined and subjective. As such, collaboration and user perception is key, hence the importance of understanding the issues and setting the right level of expectation from the start. Generally speaking though, the important thing to remember is the same relatively straightforward approach applies every time when analysing AX performance issues. Crashes and AOS memory issues, while they may be related to performance in some cases, should at least initially be treated as a separate area, but then once the call stack is identified from crash dump analysis, some of the principles discussed here may be applied if it is found to be performance related. There is a series of articles available to help with these, as summarised in this article: http://blogs.msdn.com/b/emeadaxsupport/archive/2011/04/10/so-your-aos-crashed-is-hanging-or-you-just-want-to-see-what-it-s-doing.aspx Key steps These steps are based on typical approaches we would follow on support combined with my own previous experience. 1. Set User Expectations Setting the right levels of expectation from the start is key to keeping any performance tuning project within scope. I say project here deliberately because general performance issues should be treated as such, including scoping, timelines and allocation of multiple resources. There may be questions like 'Could [X technical issue] in some way relate to this performance issue?'; bear in mind that while positive contributions should be encouraged, be careful how you use the information - be careful to stick to your original goals and not be sidetracked. Get a list of processes and validate expected durations for those processes from the end users, i.e. whether they are actually realistic or not based on the underlying logic. If you don't think it's realistic, say so, it's better to have these conversations as early as possible; ask them to define in business terms what the requirement is and if possible, provide supporting information to go with it. If possible get the target defined in terms of volume and concurrent users as well. For example: "With 200 concurrent users, we expect process 'X' to take a maximum of 30 seconds and an average of 10 seconds, for a 100 line order. We have calculated this based on the order volume a user in that area would typically need to process to meet their targets." It relates back to the principle of SMART: Specific, Measurable, Achievable, Realistic and Time related. Users saying "AX is generally slow" or "'X' process is slow" may be valid, but it doesn't provide enough information on its own to properly analyse the problem; the Performance Analyser can help but there is nothing better than first-hand information from the users. It can help to stress the importance of their role in this process. This brings us on to point 2. 2. Ask! Ask for further details and if you can't get the required information by simply asking, try other approaches such as site visits to observe users while they are experiencing the issues. If you don't get your answers, keep asking - you may well find that a lot of "noise" simply disappears and some specific issues start bubbling to the surface which you can then begin to address. Once you do start getting the information though, users need to see that their efforts are worthwhile to offer you continued support (i.e. first hand information), so ensure you at least demonstrate that you are working on it and ensure they are being kept informed (ideally, directly if you can). If you can also achieve some quick wins, even better. Some examples of questions you might want to ask the end users:
By this point (if not earlier), you should be in a position to formulate an action plan based on:
4. Install the key recommended tools There are 2 main tools which together can mostly be used to diagnose any performance issue on AX.
5. Validate setup It is important to start troubleshooting on a good solid foundation. If the problem is clearly identified with a specific process less of this may be necessary, but a quick validation of the environment at least should still be done for any performance case. The reason being that some issues with specific processes have been known to be resolved by addressing simple setup issues, for example rebuilding indexes or updating statistics on the affected tables or setting the MAXDOP setting in SQL Server to 1. You can use the following guides to check known areas of setup that can affect AX performance: http://blogs.msdn.com/b/axsupport/archive/2014/09/05/ax-performance-troubleshooting-checklist-part-1a-introduction-and-sql-configuration.aspx http://blogs.msdn.com/b/axsupport/ar...iguration.aspx 6. General performance analysis General performance issues can involve a lot of potential factors and therefore can often require collaboration across a lot of different organisations and groups within organisations, e.g. general infrastructure, development, database, AX support, desktop support, etc. In the most successful performance projects I have seen, there has been a spirit of openness and collaboration towards the shared goal of improving performance, without which people may tend to try to defend their own areas and can be less willing to contribute information if they feel there is a risk in doing so. If you haven't already, depending on the scale of the issue you may wish to consider setting up a regular conference call to share information, agree and assign actions and review progress, for example on a weekly basis. Your main tool of choice to begin with should be the performance analyser (see step 1). Following on from the configuration checklists (parts 1 a and b above), you should then move to Part 2, which can be found here: http://blogs.msdn.com/b/axsupport/archive/2014/09/08/ax-performance-troubleshooting-checklist-part-2.aspx There are scripts included in the Performance Analyser package that will help you to check all of the above areas, as described here: http://blogs.msdn.com/b/axsupport/archive/2014/09/01/microsoft-dynamics-ax-general-performance-analysis-scripts.aspx On the SQL Server tier, you may also be able to draw on the experience of the customer's DBA and they may already have a lot of relevant information which could provide some insight. Bear in mind though that they probably won't have a great deal of experience with AX and SQL tuning for AX can be different in some ways (e.g. in AX 2009, included columns are not available and index changes need to be made in the AOT). The next phase, which can also overlap to a degree, is to analyse specific processes. Having said that, it's important to get as much done at the 'general' end (e.g. setup, hardware, etc) first when dealing with general performance issues, to avoid costly and potentially unnecessary additional monitoring / analysis time later. One analogy is the funnel: the investigation starts wide, looking at general settings, gathering information, etc and can then gradually become more focused as you narrow things down. This would also apply to specific processes, but you would expect to filter down to a granular level much more quickly. Another analogy is the onion: performance tuning is iterative, where the cycle includes analysis, corrective actions/tuning, deployment of changes then review. 7.Analyse specific processes Even when investigating general performance, as mentioned above you should still get some examples from users of where processes are particularly slow. This is for 2 main reasons:
http://blogs.msdn.com/b/axinthefield/archive/2011/06/25/dynamics-ax-tracing-part-3.aspx 8.Iterative Review Review should be a regular part of the process because as mentioned already, performance tuning is iterative; resolution of some underlying technical issues may help, but then more can be identified after changes are deployed and the performance tuning is able to become more focused and in depth. However, at the same time it's important to be able to recognise when to stop tuning and move on. There is generally a 'law of diminishing returns' to be applied here, meaning in each iteration of the performance tuning of a specific process, you would expect the potential for improvement to reduce exponentially. So some kind of exit criteria should be applied (and predefined as early as possible). For example, you may have simply reached the target duration agreed with the end user or some kind of cost / benefit decision was made, such as:
Finally, review what could have been done pro-actively that can be applied in future to avoid the issue happening again and plan to have it in place on every AX implementation project. Areas to consider may include:
Performance Resource Page for Microsoft Dynamics AX Источник: http://blogs.msdn.com/b/axsupport/ar...namics-ax.aspx
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