Database
All posts tagged Database
Just a few thoughts on concepts needed to give mobile users of your SOA infrastructure the best, fastest User eXperience possible:
- If you care about speed & scalability, your web service will always check the distributed cache before querying the database.
- If you have to get your answer from your database, make sure to add the answer to your distributed cache concurrently with returning it to the user.
- Don’t ever call your primary database directly. Call one of your horizontally-scaled relational or NoSQL replicas.
- Use download-only replication to create as many read-only replicas as you need. Your replicas can contain complete copies of the primary database or just shards of data as appropriate.
- When sending data up from the clients to your servers, never let your web services insert, update, or delete directly against the primary database or the replicas.
- Have your web services drop that uploaded data in a queue and update the distributed cache while letting worker processes perform those DML operations against the primary database.
- Use peer-to-peer replication to maintain more than one read/write primary database at the top of your hierarchy.
- Remember to create and maintain more than one hierarchy in different geographies using the same peer-to-peer replication to provide even more availability, scalability, and performance to your mobile users all around the world.
- Your mobile users will be connecting to your service via slow, intermittent, unpredictable wireless data networks so always use small, efficient wire protocols like REST and data serialization like JSON.
-Rob
The profound effects of the Consumerization of IT (CoIT) is blurring the lines between consumers and the enterprise. The fact that virtually every type of mobile device is now a candidate to make employees productive means that cross-platform, enabling technologies are a must. Luckily, Microsoft has brought the power to synchronize data with either SQL Server on-premise or SQL Azure in the cloud to the world of mobility. If you’ve ever synched the music on your iPhone with iTunes, the calendar on your Android device with Gmail, or the Outlook email on your Windows Phone with Exchange, then you understand the importance of sync. In my experience architecting and building enterprise mobile apps for the world’s largest organizations over the last decade, data sync has always been a critical ingredient.
The new Sync Framework Toolkit found on MSDN builds on the existing Sync Framework 2.1′s ability to create disconnected applications, making it easier to expose data for synchronization to apps running on any client platform. Where Sync Framework 2.1 required clients to be based on Windows, this free toolkit allows other Microsoft platforms to be used for offline clients such as Silverlight, Windows Phone 7, Windows Mobile, Windows Embedded Handheld, and new Windows Slates. Additionally, non-Microsoft platforms such as iPhones, iPads, Android phones and tablets, Blackberries and browsers supporting HTML5 are all first-class sync citizens. The secret is that we no longer require the installation of the Sync Framework runtime on client devices. When coupled with use of an open protocol like OData for data transport, no platform or programming language is prevented from synchronizing data with our on-premise and cloud databases. When the data arrives on your device, you can serialize it as JSON, or insert it into SQL Server Compact or SQLite depending on your platform preferences.
The Sync Framework Toolkit provides all the features enabled by theSync Framework 4.0 October 2010 CTP. We are releasing the toolkit as source code samples on MSDN with the source code utilizing Sync Framework 2.1. Source code provides the flexibility to customize or extend the capabilities we have provided to suit your specific requirements. The client-side source code in the package is released under the Apache 2.0 license and the server-side source code under the MS-LPL license. The Sync Framework 2.1 is fully supported by Microsoft and the mobile-enabling source code is yours to use, build upon, and support for the apps you create.
Now some of you might be wondering why you would use a sync technology to move data rather than SOAP or REST web services. The reason has to do with performance and bandwidth efficiency. Using SOA, one would retrieve all the data needed to the device in order to see what has changed in SQL Server. The same goes for uploading data. Using the Sync Framework Toolkit, only the changes, or deltas, are transmitted over the air. The boosts performance and reduces bandwidth usage which saves time and money in a world of congested mobile data networks with capped mobile data plans. You also get a feature called batching, which breaks up the data sent over wireless networks into manageable pieces. This not only prevents you from blowing out your limited bandwidth, but it also keeps you from using too much RAM memory both on the server and your memory-constrained mobile device. When combined with conflict resolution and advanced filtering, I’m sold!
I think you’ll find the Sync Framework Toolkit to be an immensely valuable component of your MEAP solutions for the enterprise as well as the ones you build for consumers.
Keep Synching,
Rob
A lot has changed since the launch of Windows Phone in the Fall of 2010. Microsoft now has a compelling phone platform that targets consumers inside and outside the office. One thing that that hasn’t changed is the widespread use of Windows Embedded Handheld to solve tough enterprise mobility problems. It should be no surprise that over 80% of enterprise handhelds shipped are running Windows Mobile or Windows Embedded Handheld. They include support for barcode scanning, RFID reading, rugged hardware, every type of wireless, full device encryption, complete over-the-air software distribution and device managment support, FIPS compliance, and both capacitive touch and stylus operation. On the application platform side of the equation, they have rich support for WinForm development using Visual Studio and the .NET Compact Framework, C++ and a full-featured database with built-in sync capabilities via SQL Server Compact. They can easily communicate with WCF SOAP and REST web services running on Windows Servers on-premise or with Azure in the cloud. Support for Merge Replication means faster time to market to get device synchronizing with SQL Server with almost no coding.
Since Windows Embedded Handheld uses an advanced version of the operating system kernel used by Windows Mobile 6.5.3, many of the techniques and best practices I’ve taugh customers and developers all over the world still apply. While it still uses the slotted memory model found in Windows CE 5 with 32 processes and 32 MB of memory per process, you’ll find that numerous enhancements and tuning has taken place to give your line of business apps more of what they need. I’m talking about more memory per process and improved performance. Therefore, I’d like you to sit back and watch the video of a presentation I delivered at Tech Ed in Los Angeles a couple of years ago so you can better learn what this mobile platform has to offer in the form of better memory management and improved performance:
A recent Gartner report recommends that organizations should stay with Windows Embedded Handheld as the best mobile platform for enterprise line of business needs. Great devices are available from OEMs like Intermec, Motorola, Psion, and Honeywell just to name a few. I hope this video helps you with any memory management or performance issues you may need to deal with in your enterprise mobile apps.
Best Regards,
Rob
A decade has passed since I first started using SQL CE on my Compaq iPAQ. What started as a great upgrade to Pocket Access turned into the ultimate embedded database for Windows CE, the Pocket PC, Windows Mobile and Windows Phones. The one-two punch of Outlook Mobile synchronizing email with Exchange and SQL Server Compact synchronizing data with SQL Server helped set the mobile enterprise on fire. In 2005, version 3.0 supported Windows Tablets and progressive enhancements to the code base led to full Windows support on both x86 and x64 platforms. With the new version 4.0, the little-database-that-could has grown up into a powerful server database ready to take on the web.
We’ve come a long way and you’re probably wondering what qualifies this new embedded database to take on the Internet:
- Native support for x64 Windows Servers
- Virtual memory usage has been optimized to ensure the database can support up to 256 open connections – (Are you actually using 256 pooled connections with your “Big” database today?)
- Supports databases up to 4 GB in size – (Feel free to implement your own data sharding scheme
) - Developed, stress-tested, and tuned to support ASP.NET web applications
- Avoids the interprocess communications performance hit by running in-process with your web application
- Row-level locking to boost concurrency
- Step up to Government + Military grade security SHA2 algorithm to secure data with FIPS compliance
- Enhanced data reliability via true atomicity, consistency, isolation, and durability (ACID) support
- Transaction support to commit and roll back grouped changes
- Full referential integrity with cascading deletes and updates
- Support ADO.NET Entity Framework 4 – (Do I hear WCF Data Services?)
- Paging queries are supported via T-SQL syntax to only return the data you actually need
Wow, that’s quite a list! SQL Server Compact 4.0 databases are easily developed using the new WebMatrix IDE or through Visual Studio 2010 SP1. I’m loving the new ASP.NET Web Pages. It reminds me of the good old days of building web applications with Classic ASP back in the 90′s with Visual InterDev and Homesite.
What about Mobility?
Since SQL Server Compact owes its heritage to mobile and embedded versions of Windows, you might be wanting to know what our story is there. The good news is that you can build and deploy v4.0 databases on Windows XP, Windows Vista, and Windows 7. If you want to implement an occasionally-connected solution that utilizes the Sync Framework, Remote Data Access (RDA), or Merge Replication, you’ll need to stick with SQL Server Compact 3.5 SP2. Time and resource-constraints prevented the Compact team from enabling these features. Luckily, single-user WPF/WinForms database applications running on Windows Slates, laptops and Windows Embedded Handheld devices will work just fine with the v3.5 SP2 runtime. Get a jumpstart with this by pickup up “Enterprise Data Synchronization with Microsoft SQL Server 2008 and SQL Server Compact 3.5 Mobile Merge Replication” at http://www.amazon.com/Enterprise-Synchronization-Microsoft-Compact-Replication/dp/0979891213/ref=sr_1_1?s=books&ie=UTF8&qid=1281715114&sr=1-1 to start building those MEAP solutions.
With the tidal wave of Windows Slates hitting the market, a secure, powerful mobile database that allows users to work offline and syncs with SQL Server is definitely going to be a hot item!
So run, don’t walk to the Microsoft Download site to download the Next-Gen database for the web:
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=033cfb76-5382-44fb-bc7e-b3c8174832e2
If you need to support occasionally-connected mobile applications with sync capabilities on muliple Windows platforms, download SQL Server Compact 3.5 SP2:
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=e497988a-c93a-404c-b161-3a0b323dce24
Keep Syncing,
Rob
