Darren Shaffer

SQL CE/SQL Mobile Replication and Firewalls

I recently decided to install Norton Internet Security 2006 on my development machine, moving away from the Windows XP SP2 firewall. While this product (NIS) works great, a few days later I opened a CF2/SQL Mobile application I'm working on for a customer and attempted to merge replicate from a device to SQL Server 2005 installed on the same machine. I received the following error: "Unable to synchronize the local database with the server." The exception details explained "Header information is either corrupted or missing." The CF2 application uses AddOption.CreateDatabase in the replication code to create the initial SQL Mobile database on device upon initial replication with the server. I noticed after the error above, I ended up with a small, non-functional SQL Mobile database in my mobile app folder, but the replication clearly wasn't successful.

Whenever there is a problem with merge replication between SQL CE/SQL Mobile and the server, my first step is always to validate that I can get to the IIS virtual directory and hit the SQL CE/SQL Mobile replication dll there. Opening Pocket Internet Explorer on device, I attempted to navigate to http://{myServerName}/{virtDirName}/sqlcesa30.dll. When everything is configured properly, this yields a page that simply states "SQL Server Mobile Server Agent 3.0" (in the case of SQL Mobile).

So this test passed and I began to suspect perhaps the transition from the Windows XP SP2 firewall to Norton Internet Security might be my issue. After turning off the Personal Firewall component of NIS, the problem continued to occur. So I proceeded to hard reset my device, reinstall all 3 SQL Mobile CABs, reinstall the SQL Mobile Server Tools on my dev box, drop and recreate my publication, etc. All to no avail. After escalating to my friends on the Microsoft SQL Mobile team, they got me thinking that perhaps NIS has something in it other than the firewall causing this problem. I finally completely turned off NIS (the entire package) and the problem disappears. So here is Microsoft's description of this issue so that you can all be aware of it:

Problem:

When a device is connected to a desktop where NIS is running, then merge replication fails giving the error -"Header information is either corrupted or missing"

Cause:

This problem happens because Norton Internet Security strips off the Content-Length HTTP Header field from the HTTP messages. I have attached two snapshots to show this problem. NIS_Enabled.jpg is the snapshot of the HTTP trace information when Norton Internet Security is enabled and you can notice that Content-Length is replaced with dashes. This is something NIS does for any website, you can visit yahoo.com or msn.com from the device and you would still notice the content-length being stripped off. NIS does it because of certain content-length buffer overflow attacks that are possible. We rely on this content-length attribute while reading the HTTP data and since this attribute is missing, the client agent throws this error.

Other observations:

1. This problem does not occur when NIS is running on the IIS box

2. This problem does not occur when we run merge replication from a device emulator of a machine running NIS

I'm working with the SQL Mobile team to figure out a way to configure NIS so that it does not strip the Content-Length from the HTTP header. If any of you have solved this problem, please let us know.

In the meantime, I have seen a number of posts in the microsoft.public.sqlserver.ce newsgroup and the new SQL Mobile forum where others have run into this issue. At least we now know what's going on.

I'll keep you posted on the solution when one is available.

-Darren

SQL Mobile Downloads and Samples Available Now

It was great seeing many of you at the VS2005 Launch Event in Denver yesterday. Microsoft just posted some fantastic resources and samples for SQL Server 2005 Mobile Edition (SQL Mobile).

Here are the downloads and a description of each:

a. Microsoft SQL Server 2005 Mobile Edition Server Tools - The package installs the SQL Server Mobile Replications Components on the machine running the IIS server. The components are required for connecting the SQL Server Mobile database on a mobile device to SQL Server 2000 SP3a database and later versions. Link to download: http://www.microsoft.com/downloads/details.aspx?familyid=6ed0fb7e-7c05-4f59-879a-8fb619e36612&displaylang=en

b. Microsoft SQL Server 2000 Service Pack 4 Replication Components – The package installs the SQL Server 2000 SP4 replication components on the machine running the IIS server. The components are required for connecting the SQL Mobile database on a mobile device to a SQL Server 2000 SP4 database. Link to download: http://www.microsoft.com/downloads/details.aspx?familyid=a0241f9c-79b1-4011-81e3-2601aa701e02&displaylang=en

c. Microsoft SQL Server 2000 Service Pack 3a Replication Components – The package installs the SQL Server 2000 SP3a SQL Server 2000 SP3a replication components on the machine running the IIS server. The components are required for connecting the SQL Mobile database on a mobile device to a SQL Server 2000 SP3a database. Link to download: http://www.microsoft.com/downloads/details.aspx?familyid=a9e0cea0-6f8d-4625-af71-fc8d671f64b6&displaylang=en

d. Microsoft SQL Server 2005 Mobile Edition Device SDK – The SDK contains the product installers files for installing SQL Server Mobile on the mobile devices, and it also contains the DLL’s and Header files required for developing SQL Mobile applications on the Desktop. Link to download: http://www.microsoft.com/downloads/details.aspx?FamilyId=5BD8ABAA-5813-4DB3-B23A-24551DE2ECC1&displaylang=en

e. IBuySpy Delivery 2005 Developer Toolkit Sample Application– The Toolkit is a sample e-commerce storefront to demonstrate how simple it is to create scalable applications for the Microsoft^®.NET^® platform by using SQL Server Mobile . Link to download: http://www.gotdotnet.com/Community/UserSamples/Details.aspx?SampleGuid=7A5F64B0-4E64-4A72-A2C9-994A0C55CECD .

Apart from these the following are also available –

EULA for SQL Server Mobile Device SDK: http://download.microsoft.com/download/2/4/8/2482E95D-00FD-4374-BD15-57A8C4C34444/SSMREADME.htm

ReadMe file for SQL Server Mobile Device SDK: http://download.microsoft.com/download/2/4/8/2482E95D-00FD-4374-BD15-57A8C4C34444/EULA.rtf

Help File for the SQL Server Mobile: http://download.microsoft.com/download/2/4/8/2482E95D-00FD-4374-BD15-57A8C4C34444/ssm3chm.chm

-Darren

SQL Mobile Webcast 11/16/2005

Hello Fellow DotNetJunkies,

I am presenting a webcast Developing SQL Server 2005 Mobile Edition Applications next Wednesday November 11, 2005 at 11am Pacific time. You can register at: http://www.devx.com/SummitDays/Door/26588. Beyond a primer on SQL Mobile and some great demos, I will share my top lessons learned programming with SQL Mobile and also with synchronizing data using merge replication, remote data access, and web services.

So speaking of SQL Mobile, I often field questions about the specific libraries that SQL Mobile installs on your device and on your server (in replication/RDA scenarios). Here is a handy quick reference guide to the libraries that constitute SQL Server 2005 Mobile Edition:

Quick Reference Guide to SQL Mobile libraries

- SQLCESE30.DLL – Storage Engine

- SQLCEQP30.DLL – Query Processor

- SQLCECA30.DLL – Client Agent

- SQLCESA30.DLL – Server Agent

- SQLCERP30.DLL – Replication Provider

- SQLCEME30.DLL – Managed Extensions

- SQLCEOLEDB30.DLL – OLE-DB Provider

- SQLCEER30xx.DLL – Error Strings Localized in locale ‘xx’ Where xx belongs to {EN, TW, CN, DE, ES, FR, IT, JA, KO}

Finally, the RTM of Visual Studio 2005 and SQL Server 2005 is now available to MSDN subscribers. I've installed both on a couple of machines now and am happy to report that they install nicely after removing all of the RC, CTP, and Beta versions of these products. If you plan on having VS2005, SS2005, and VS2003 on the same machine, the good news is that I have not seen any issues with this as long as the install order of VS and SS follows a simple rule: "always install VS2005 last". A number of the other MVPs have also reported success in running all three of these products on the same development PC. So if you're an MSDN subscriber, now is the time. And if not, launch is almost upon us (tomorrow) and you are going to like what you see, especially with smart device development and tight integration with SQL Mobile.

I will be at the Microsoft "Best of Launch" in Colorado Springs on 12/1. Register at: http://msevents.microsoft.com/cui/EventDetail.aspx?culture=en-US&EventID=1032282578

and also at the main Denver Launch Event on 12/6 in the "Ask the Experts" area. Register at: http://www.microsoft.com/events/2005launchevents/default.mspx

You will receive free copies of VS2005 and SS2005 at these events, so stop by, have a look at the cool new features in the 2005 tools, and bring along your Compact Framework and SQL CE/SQL Mobile questions!

-Darren

Hello .NET Junkies

Hello - I'm Darren Shaffer and welcome to my BLOG on dotnetjunkies.com. A sincere thank you to Donny Mack for this opportunity.

I'm a founding member and Principal Software Architect for Connected Innovation based in Denver, CO (www.connectedinnovation.com). I'm also a .NET Compact Framework MVP and frequent speaker for MSDN, Microsoft Events, and user's groups throughout the Western US.

CI is a unique organization - we are a collection of Microsoft MVPs, RDs, and senior .NET talent who provide software services to corporate clients and directly to Microsoft. We specialize in a few leading-edge areas including Windows Mobile/CF, Location Server, MapPoint Web Service, Smart Clients, and SQL Server 2005. If you are an MVP or recognized expert in one of those areas with an interest in being brought to bear on client engagements, feel free to contact us or visit with one of us at TechEd, MEDC, PDC, MVP Summit, etc.

So what can you expect from my BLOG? I am a Compact Framework MVP and I have had the rich experience of designing and delivering some 25 Compact Framework enterprise apps since the CF was in beta. I have a special interest in SQL CE and SQL Mobile and work newsgroups that cater to those topics (there are a number of just plain outstanding MVPs in the Compact Framework newsgroups who more than service every question, so I looked for areas that were NOT being well cared for by non-Microsoft experts). With that said, I will use this BLOG to share solutions to difficult challenges I face in my numerous (usually concurrent!) client engagements as well as frequently asked questions I find myself answering in the Microsoft newsgroups.

I will be kicking things off with a multi-part series on SQL Server 2005 Mobile Edition beginning this week. I am in the process of completing the SQL Mobile chapter in Wiley's upcoming SQL Server 2005 Bible and will share some tips and insight into this powerful new database designed for the Windows Mobile platform and why it is more than just the next version of SQL CE.

I look forward to using this forum and welcome your feedback. -ds