NAS - NAV vs SQL server environment

bhalpin

Hi.

I have an issue with the NAS process 'hanging' periodically when accesing a NAV db on a NAV db server. The problem is random, but very troublesome.

At another installation, NAS has been ticking along beautifully for nearly a year now with no glitches whatsoever. That db is on an SQL (2005) server.

So, my question is this: Is there any general opinion about the stability of NAS in NAV vs SQL database server environments?

Thanks in advance.

kine

1) I have similar problem when using NAS on same server as MS SQL and th platform was 64bit. when I disabled the Shared Memory protocol on MS SQL, problems stopped.

2) Check the NAS session when it hangs on the MS SQL and look at the wait type and last executed command.

bhalpin

Thanks Kamil.

But, I have the opposite problem: On SQL everything is fine - its on the NAV db server that I am having the problems.

Bob

garak

I have an issue with the NAS process 'hanging' periodically when accesing a NAV db on a NAV db server. The problem is random, but very troublesome.

Did you find out in which process the NAS hangs? Maybe the NAS is blocked by a other user or NAS process?
Which version of NAV? Because for 4.03 exist a update KB 948302 -> Description: "NAS stops responding to events when a lock timeout occurs"

https://mbs.microsoft.com/knowledgebase/KBDisplay.aspx?scid=kb;en-us;948302

bhalpin

Hi.

When NAS boots into the db, it creates a timer event to fire a particular codeunit every ten minutes. Details of the processing performed by the codeunit are appended to a daily log, and MESSAGE() is used at the start and end of the codeunit to record the start and end of the processing in the Event Log. Things work fine for several days, and in the event viewer you can see the start and end events every 10 minutes.

But four times now the events in the log just stop. NAS' status in the NAS manager shows 'Started', but it is noy cycling as it should. And, the log file it writes to is locked open. When we stop NAS and then restart it, all is well - untill the next occurance.

In two of the cases, shortly after restarting NAS I get an error dialog asking permission to report the error to MS. Digging into the details of the error I get to a cab file with all sorts of weird stuff in (possibly Martian?) I have opened a support incident with MS about this, but ... I guess we'll see.

My expectations of actually solving the problem on the present platform are slim - this seems like one of those 'life is too short' problems, if you know what I mean.

My reason for starting this thread was really to test the opinions of running NAS on NAV vs SQL and consider switching to SQL if it seemed to be a more stable platform.

Bob

kine

1) Add some debugging messages into your process to see what's happening
2) Is the process doing something with printing? (running some reports?)
3) Is there some possibility of neverending loop?
4) Are you re-enabling the timer in all cases (if you are disabling it in the code)?

Waldo

My experience is indeed that sometimes the NAS is very unstable. Sometimes the shared memory is an option (like Kine mentioned), sometimes not.
In one environment, we have a test and live. Objects 100% the same. Configuration 100% the same. We have a NAS to the test environment and one to the live (both native). TEST runs fine, LIVE is a mess.

Here is a workaround though (which I don't want to promote, but still, in some cases, where you are just desparate, this can be of use).
1) Create some kind of exe that kills every nas.exe or nassql.exe. This can be easily done in .NEt or whatever
2) configure the NAS service to be restarted after a crash (all the time).
that way, if it hangs, you will kill it and it will automagically restart after that.

garak

In my NAS environment (customers and her in the firm) i restart the NAS periodicly new. for this i use PSTools.
The reason is, for example, to get free the allocated memory.

Waldo

That's even better! No need to create a custom exe here.. .
thanks!

garak

Waldo wrote:

No need to create a custom exe here.. .
thanks!

Thats was the reason why i use PSTools. So i can also Start/Stop/Query the NAS from a other pc. And the other reason was, I was to lazy :oops:

ajhvdb

How do you use this? I always thought by scheduling "pskill" I can restart the NAS but have not used it; what would happen if the NAS was writing data at that moment?

garak

what would happen if the NAS was writing data at that moment?

If you kill a client (the NAS is also only a client without a GUI) that runs a transaction, the DBMS (here SQL Server engine). makes a rollbak of all the transactions that are not commited.

jlandeen

I have seen similar problems with NAS when working with error trapping in version 5.0.

I did find that in some cases NAS was locking up. This was eventually tracked back to some low level error handling problems when trying to trap & properly handle errors (via the new GETLASTERROR command). There were some very rare cases where errors were not trapped, they propagated all the way up and then (as per normal) NAS tried to display the error to the user. As NAS has no User Interface when it hits an error that it cannot display - it fails.

There was nothing explicitly mentioned in SP1 for version 5.0 but apparently it's NAS executable is supposed to be more stable.