SQL Linked Server by IP Address

A recent SQL Server problem I had was to setup a Linked Server from one SQL 2005 server to another, with a couple of specific requirements: The destination server could only be accessed by IP address, but the customer wanted to be able to identify the server by name in SQL code.

This should have been simple, but as I'm blogging about it you may be able to guess that it wasn't quite so straightforward...

It started promisingly. This is how to add a SQL linked server via SQL Management Studio if you can access it by name:

If you want to specify the other parameters, it seemed to make sense to specify 'Other data source', and 'Microsoft OLE DB Provider for SQL Server': That was easy... till I tried to query the server, which failed with a timeout. Then, when I opended the properties of the Linked Server, the Data Source information had gone:

If you specify the OLE DB Provider for SQL Server, then the Data Source is lost.

To get round this, I had to add the linked server via the sp_addlinkedserver system stored procedure, and specify a provider of 'SQLNCLI' (the native SQL client), and not SQLOLEDB (the OleDb provider for SQL Server). The following example shows how to do it.

sp_addlinkedserver
@server = 'REMOTESQL' -- Name used in queries
, @provider = 'SQLNCLI' -- SQL Native Client
, @srvproduct = '' -- Cannot be null, and if 'SQL Server' then you cannot specify the datasrc
, @datasrc = 'SERVER=10.0.0.1' -- IP Address of the server
, @catalog = 'MYDB' -- database name on the server, if required

Notification.asmx

While investigating a stability issue on a customer's CRM 3.0 Server recently, I figured I needed to identify what the calls to notification.asmx were. These calls are made every 30 seconds, and can be identified in the IIS logs as follows:


2008-09-08 11:11:44 192.168.2.107 POST /MSCRMServices/notification.asmx


Each call results in a SQL query to the MSCRM database, like the following:


exec sp_executesql N'Select EventId, EventData, CreatedOn From Notification Where CreatedOn > @CreatedOn', mailto:N datetime', @CreatedOn = 'Aug 14 2008 3:08:02:370PM'


A reasonably detailed check on the internet suggested nobody else knew what notification.asmx was doing, or if they did, they weren't telling.


I won't bore you with the details of how I found it, other than my past experience with CRM 1.2 helped, but in case you're interested, it's used for processing CRM 1.2-style callouts. Unfortunately this had noting to do with the ultimate problem, but at least I now know to eliminate it from my enquiries.

Cannot set Price List when Previewing Form

I came across a quirk of the Preview functionality of the CRM 4.0 Form Editor. When previewing an entity with a relationship to the price list - e.g. opportunity, quote - the Price List lookup doesn't display any price lists, so you can't set one. As far as I can tell this is due to the multi-currency functionality - the lookup normally filters by currency, but this logic is missing from the preview. Manually setting a currency in the preview form doesn't help.

This caused me an issue once when testing client script, but there's a fairly simple way around it - you can still set the price list code. This is something I commonly do if the customer has just the one price list. Here is some sample code I use in the form load event:

if (crmForm.FormType == 1)
{
var o = new Object();
o.id = '{A0E0F731-E96C-DD11-AABD-0003FF74F5B7}'; /* Change this Guid */
o.typename = 'pricelevel';
o.name = 'Standard Price List';
var a = new Array();
a[0] = o;
crmForm.all.pricelevelid.DataValue = a;
}

Note that this is only appropriate in a single-currency scenario. If you have multiple currencies, you'd be better off putting the code in the change event for the currency field, and picking an appropriate price list for the currency.

SQL Timeouts in CRM - Generic SQL Error

I often find myself answering forum posts about SQL errors (the most common error is 'Generic SQL Error'). By far the most likely cause of this error is a timeout when accessing SQL server. If this is a case your options are to increase the timeout, or to try and ensure the query does not take so long.

Increase the Timeout
The SQL timeout is controlled by a registry value on each CRM server:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM\OLEDBTimeout

This value does not exist by default, and if it does not exist then the default value will be 30 seconds. To change it, add the registry value (of type DWORD), and put in the value you want (measured in seconds). Then you have to recycle the CrmAppPool application pool for the change to take effect (this is a step most Microsoft documentation omits to mention); do this we IISReset, or less drastically via iisapp.vbs

Reduce the time taken by the query
This may not be so simple, as you may have little control over the query. If the query is run as a result of your code (e.g. through a RetrieveMultiple request), then you may be able to make useful changes. For example, RetrieveMultiple requests on activities are not necessarily processed very efficiently by CRM (the problem is the way that is accesses the activity parties), and I've been able to make significant improvements by using a FetchXml query instead, which gives closer control over the joins used.

Otherwise, the other query optimisation option is to add indexes in SQL Server. This is a massive topic in its own right (I used to deliver 5 day training courses just on this topic), so I'm not going to go into detail here. The general steps are:

1. Identify the SQL query that takes the time - I use CRM tracing for this - http://support.microsoft.com/kb/907490
2. Use the SQL Management Studio and SQL Profiler to identify the query execution plan and to get recommendations about possible indexes

There are 2 important things to take into account:

1. Although adding an index may improve the performance of one query, it can adversely affect other SQL operations - most obviously data updates. There is no easy solution to this, though the SQL Profiler can help you if you capture and analyse a representative sample of SQL operations
2. Some out-dated CRM documentation suggested that it is unsupported to add indexes to the MSCRM database. However, adding indexes is supported, providing the index does not implement any constraints (i.e. it's not a UNIQUE index)

CRM SDK Update - 4.0.6

There's been a new release of the CRM 4.0 SDK - available here http://www.microsoft.com/downloads/details.aspx?FamilyId=82E632A7-FAF9-41E0-8EC1-A2662AAE9DFB&displaylang=en

There are no major changes in this release, but there are a few aspects of note:

1. The Plug-in example code now uses the DynamicEntity class as recommended
2. The code for use of ImportXml, ExportXml and PublishXml looks like it now passes all required XML nodes
3. There are now instructions for setting up a web reference in Visual Studio 2008
4. The PrependOrgName client-side function is now documented (and hence supported)