Friday 20 July 2007

Refreshing Screen Info in V4 PII

After a lot of further studying it seems that it is not Lock / unlock that have been disabled but the flag that deems whether the screen needs redrawing that does not get set by the fact of updating the labels of the columns in a grid so my problem may not be V3 to V4 related it may be general.

Great, well I have a call in and I am trying all sorts of detours in order to get the form to update the column headers, so far the only reliable one is for the User (!) to click on the scroll bar below the grid.

A single click is enough to redraw :-(.

I have not tried to move the screen back into V3 in order to see how V3 will cope with it, it seems a rather retrograde step to undertake especially as it is meant for a V4 implementation.

Anyhow will post on this subject again later.

Take Care
Sven

Thursday 19 July 2007

Performance issues resolution in Ax Part I

This is a subject on which a lot has been written by any number of people so I will concentrate on some small parts of the issues relating to this, and this is not meant as anything else but a starting point.

Mostly when you have problems in Ax, as in most other ERP systems :-), it is related to some sort of contention that is concurrent access to key central information, or alternatively to large quantities of data being used/created.

In most of the instances I have seen the quickest fix on SQL is always just adding more memory, not that I am a big advocate of throwing money at the problem but well that is normally the cheapest solution these days.

In SQL 2000 and 2005, the main issue is centered around one fact, lock escalation, basically your server can if it deems to be running out of memory decide to start locking not each row but a page (unit of storage used to contain multiple rows in the database) and even the whole table. When this happens you tend to get a situation where everyone is waiting for each other.

Picture Picadilly circus bus stop on a busy afternoon where you have lots of busses all coming in to pick up / drop off passengers and having to wait for each other and thereby causing havoc for other traffic, that is the best physical representation.

In Ax say the CustTrans table is concerned or InventTrans then as one process is using it another 5 different ones want to use it too, they cannot as the first is blocking and they use other tables which they then block for others thus making a traffic jam in the database.

SQL decides to do this lock escalation when it has used more than a certain percentage of the available memory that it has to manage locks, thus if you give it more memory to play with it is less likely to do lock escalation and therefore to create the traffic jam.

In SQL 2005 some new functionality has been added concerning Index Lock escalation, however this is hard to add in Ax as information on the indexes, as these are created by the syncronization engine. You would have to add the information by hand on each index :-( after creation and then redo this everytime Ax runs a syncronization.

Additionally as you can see in this KB where means of reducing the lock escalation are discussed it is possible to switch of using the startup flag -T1211 however the resulting error condition of it running out of memory is not pretty.

One option that seems intriguing is the option of making an incompatible higher level block

BEGIN TRAN
SELECT * FROM mytable (UPDLOCK, HOLDLOCK) WHERE 1=0
WAIT FOR DELAY '1:00:00'
COMMIT TRAN

in Ax the tables classically affected are a series of well known ones, the problem with the above in Ax (as well as most other ERP's) is that one hides others etc. If f.ex. you resolve your issues on CustTrans then perhaps CustTransOpen or CustSettlement becomes the problem etc etc so this is often not a solution that we can use to resolve our escalation issues, also unless we do the locking for the whole business day we do not handle all the cases :-(.

Changing our queries is the next possibility mentioned to create smaller transactions.

Well, that is something that is possible in a limited fashion, you will have to clarify functionally with the business whether they can accept the consequences, f.ex. not make sales orders with moe than xx lines in them. Not do recap invoicing, etc etc.

What you can do is use the system to help you detect where you have problems and also use the system to dissect exactly the problem is being originated from.

A number of tools are availeable to you, the main one which I recommend all Ax sysadmins to get familiar with is the SQL tab under the User Options of each User.

This provides an invaluable help in order to get information about what parts of your system are not performing as expected.

What I suggest all sysadmins to do is to as a minimum activate the SQL tracing set a threshold of perhaps 2000 (2 secs it is in milliseconds) and to store long queries and deadlocks in the Table (database).

This will store in the database (accessible under Administration/Inquiries/Database/SQL Trace log the detail of every time a query took more than 2 seconds to execute, including the complete call stack of the process when this happened. You can even jump directly to the offending code and view / edit it.

With a little reflection it is always possible to optimise such queries and to thus reduce your performance issues, it is just a question of thinking about it clearly.

In V4 a few impediments have been placed on your way to having this level of information you have to enable Client Tracing on the AOS instance otherwise the table will be empty as the process will not be called.

Also in V3 KR1+ you have an extended toolkit that you can install, after installing the KR which you should have acces to through customersource or partnersource this allows you to control in detail what is being tracked and also allows you to log blocking behaviour, any process waiting more than 3 seconds on another will automatically log the fact that it is being blocked and thus you can see the effect that the "picadilly peak hour jam" has had on your system.

The good thing about logs is you can be factual about the increase / resolutions that you apply to your system.

Unfortunately MS have not seen fit to extend the above tracing extension into V4 probably because it was a separate development path. I have I think now managed to migrate most of it onto a V4 SP1 based system, the only issue I have is with the blocking monitor, I need to work a little on the SQL side to find out what I need to do exactly in order for it to operate.

Once it is complete I will post it here for you.

Take Care
Sven

Monday 16 July 2007

New Head of MBS Good or Bad ?

It seems MS keeps on killing off the MBS leaders, well not really killing off but they all seem to move on at a pace which is not conducive to trust in a business area where turnover is frowned upon.

Now we have Kiril Tatartinov as the new head of MBS.

He is to replace Satya Nadella who left in March 07.

Tami Reller was interim Manager, and is also leaving the MBS sphere, to take on new roles elswhere in MS.

Doug Burgum who was the manager for a long time left as recently as last year.

All in all a rather turbulent leadership of a division that now accounts for more than 1 Billion of Bill's yearly revenue.

Personally I have no truck with any of the above characters, the only issue I have is that it seems that MS has not really understood that they need to lead this thing, and that changing managers every 3-6 months is not a positive message to send.

I had hoped that Satya taking over was a sign of them wanting to go for the Dev environment type of tool, seeing as his background was solidly anchored in the Development tools team at MS.

However he / it was not given a chance to mature, and he was moved probably because the business did not show sufficient momentum or because he did not feel it was important enough for him.

I do not see Kiril as a strategic choice, I could be very wrong of course what do you think ?

I see him more as yet another stop gap solution for the role.

Why was Tami not given longer to try to perform ?

So is this the begining of the end ? Are MS looking to sell off the division ?

Some were already speculating when Satya was moved, have a look here at Josephs blog. (comments)

There are over 3000 people in the MBS division however, and some are well integrated into MS and cross pollination of job roles is something MS excels in (The average time in job is around 18 months :-) ). I think it very unlikely that they would sell.

Take Care
Sven

Sunday 15 July 2007

Dynamics Ax 4 SP2

At my last MS presentation there was a big part of the session devoted to the coming of this SP in June this year, and one thing they mentioned which I am very much looking forward to is that it should include some AIF methods allowing for updates of data.

Today the AIF is purely an Insert or Send style interfacing tool.

Of course this is not my only gripe nor others for more go to Dave's blog on the subject he is asking for anyone having live implementations to go and tell him what they have live.

Unfortunately I have so far only got a Proof Of Concept up and running so I do not have any live flows yet. However we will have when we can trust and ruggedize the application probably somewhere around 20 Companies doing SO-PO type flows with automated corrections at several levels.

The proof of concept shows it is possible but with a lot of code changes to ensure that the AIF is operational at all times.

We had issues with the COM connector (.NET) we had issues with the non existent update methods etc etc.

Anyhow more on this later but please follow up on Dave's blog and make him feel less alone on the forefront of this issue.

Take Care
Sven

Tuesday 10 July 2007

Refreshing screen info in V4

I have come accross a small change in behaviour from V3 to V4 which could potentially be rather adverse in its effects.

In V3 if you want to update a screen f.ex. and refresh it in a uniform manner then you called

element.lock()
/*
did all your manipulation of screen elements
called redraw or refresh (if you needed to re-read the data)
*/
and
called element.unlock()

The functions are still there but they currently seem to do nothing, I suspect it is related to MS teams taking over some of the screen painting functionality and they are probably using some other MSFT code package to update screen information. But this leaves me pretty much in limbo as I have to get the user to activate the scroll bar to change the screen elements as redraw seems to have been de-activated as well.

Anyone else noticed the above and more to the point has anyone found a workaround to this annoying little bug ?

I will share here if I find one, my google help engine has not worked :-), I have not seen it commented publicly anywhere yet. And on the MS help the only discussion thread I could find was from 2004 and a bit off topic.

Take Care
Sven