SDS Examples

Exploring SDS cloud services.

Updated SDS Wish List

2008-12-06

I updated the Wish List document to record that partial support for HTTP HEAD was added to SDS in November 2008. Also marked the "do not return entitiy bodies on PUT/POST" item as closed out. SDS never returned these bodies and that item should not have appeared on the list. Finally, added two more items to the list: Provide Support for HTTP Digest Authentication and Support Permission-style Access Security based on HTTP Method + URI

Of course, all feedback is welcome on the SDS Feedback page.

SDS Feature Wish List

2008-11-30

This SDS Feature Wish List page contains features and other 'wish list' items I've collected while working with Microsoft's SDS. You might notice that most of the requests I list here relate to 'application protocol' level items - HTTP. That's because I cam currently most interested in these issues and I have not found too many others covering the same space. I know there are lots of important database-related features that SDS can include, too. I leave the work of documenting those feature requests to others. Of course, all feedback is welcome on the SDS Feedback page.

SDS Photo Demo Web App

2008-11-15

This demo stores @200 original images (plus another 400 thumbnail and preview versions) along with JS and CSS files directly in SDS storage (about 80MB in all). A small C# ASP.NET handler accepts anonymous requests, processes them and, when needed initiates authenticated requests to an SDS-Proxy that then talks directly to SDS servers to get the images, scripts, and stylesheets.

The home page is HTML generated using XSLT against the Entity list returned from SDS. The only files on the web server are the C# DLL, a single XSLT file, and the web.config file. No HTML, no CSS, no JS, no images. All those are stored in SDS.

NOTE: For this demo, minimal caching is used on the client in order to show the speed of SDS even when using intermediaries such as the SDS-Proxy. Images (some over 1MB) are currently cached for ten minutes to show relative speed during a single session. In a production application, additional caching would be used to reduce avg. page load to less than 1 sec.

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too. Of course, all feedback is welcome on the SSDS Feedback page.

Updated SDS Provisioning Client Supports JOIN, ORDERBY, and TAKE

2008-11-05

This update of the existing Provisioning Client now points to the 'new' SDS data cluster that supports JOIN, ORDERBY, and TAKE queries.

During the last week of October 2008, the SDS team released an update for SSDS (now called SDS. This update supports new query features such as JOIN, ORDERBY, and TAKE (top). Whe the SDS team released the new update, they posted it to a new set of servers. For that reason, data accessed with this client will not be the same physical data as that accessed with the previious release.

There's nothing fancy or new in this release, except for point it to the new servers. All the query magic happens on the SDS servers themselves. There are some additional documentation items that I'll add over the coming days to bring the query hints into line with the new features. I also still have binary upload support to add to this client sometime soon. If you have a feature in mind, let me know (see the comment links on this page) and I'll consider it for the next update.

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too. Of course, all feedback is welcome on the SSDS Feedback page.

Updated SDS PROXY Supports JOIN, ORDERBY, and TAKE

2008-11-01

This update of the existing SSDS-Proxy server now points to the 'new' SDS data cluster that supports JOIN, ORDERBY, and TAKE queries.

The SDS-Proxy is meant to be a 'front' to the actual SDS data servers. I use it in my programs instead of the actual SDS data servers. SDS-Proxy offers some additional caching as well as a 'normalized' URI pattern most HTTP/REST folks will recognize: http://amundsen.com/sds-proxy/[authority]/[container]/[entity]. SDS-Proxy supports GET, HEAD, POST(create), PUT(update), and DELETE methods. SDS-Proxy recognizes the standard SDS MIME-Type: application/x-ssds+xml as well as any MIME-type used when you stored your 'binary' objects to SDS (image/*, text/plain, etc.).

SDS-Proxy can be reached using your existing SDS credentials (via HTTP Basic Auth) at the following URL: http://amundsen.com/sds-proxy/. You'll need an HTTP client kit (or utility) that allows you to manipulate HTTP headers, URI, and bodies. I use the very helpful WFETCH.EXE, but other tools such as wget or cUrl will work fine, too.

During the last week of October 2008, the SDS team released an update for SSDS (now called SDS. This update supports new query features such as JOIN, ORDERBY, and TAKE (top). Whe the SDS team released the new update, they posted it to a new set of servers. For that reason, data accessed using this proxy will not be the same physical data as that accessed with the previious release.

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too. Of course, all feedback is welcome on the SSDS Feedback page.

Entity-Binding Strongly-typed DataSets for SSDS

2008-10-13

This update contains a new demo app: Entity-Binding.

The Entity-Binding demo shows how to generate and use standard strongly-typed DataSets to access SSDS data. I built this app to show the DataSets get along just fine w/ SSDS. I created an XSD document to match my Task List entity. I then used XSD.exe to generate a CS class that defines a strongly-typed DataSet to match the Task entity. Finally, I created a small console app that gets the live Task list, loads it into the DataSet and enumerates the DataSet to the console.

This is a really simple demo. Other things are possible including adding support for Views (sorting, filters); supporting DataSet changes (add, update, delete); and full-fledged data-binding for WinForms controls like DataGrid, etc. It would also b e possible to add more automation the process of generating the classes from live SSDS data. If there is more interest in this project, I'd consider spending more time. Let me know!

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too. Of course, all feedback is welcome on the SSDS Feedback page.

General Update Posted

2008-09-08

This update contains changes to three samples: The SSDS-Proxy, SSDS Provision Client, and SSDS Deploy.

SSDS-Proxy (1.5) now returns authority lists for the logged in user and has basic support for BLOB files. This also required updates to the internal HttpClient class and the Caching class to support BinaryWrite. More work is needed soon (for example, this version does not support uploading BLOB files), but this is a bit step forward for making both the Proxy and the underlying HttpClient much more versatile.

SSDS Provision Client (1.7) now supports reading and deleting BLOB files (no upload yet). It also returns the list of authorities for the logged-in user. This means it's now possible to update the general login UI to let users login right away and get direct feedback if the login fails.

SSDSDeploy.exe (1.1) has a bug fix for large files. Actually, the existing code had a nasty bug in the routine that declared the async callback method for the upload. This prevented files larger than twice the buffer size from uploading properly. I also added feedback during the upload process in the for of 'progress dots.' Until I update the SSDS-Procy and Provision Client to support BLOB uploads, this is the easiest way to upload BLOB files to your SSDS account.

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too. Of course, all feedback is welcome on the SSDS Feedback page.

Version 1.0 of SSDSDeploy Demo Posted

2008-08-18

This application allows users to upload one or more files (using wildcards) from their workstation to the SSDS servers (see syntax examples below). Currently SSDS does not properly handle entityIds with "/" or "\" in their name. For that reason, a valid upload entity name is "filename.ext", but *not* "/images/filename.ext" I have a possible work-around using some other URL-safe character as the 'folder seperator' (":"?), but I'm not sure how soon I'll update the codebase to support this.

One of the interesting bits of code in this demo is the GetMimeType(string filename) method. This uses the extension of the disk file to lookup the MIME type in the Windows Registry.

Here's the sample syntax for SSDSDeploy.exe

SSDS Deploy Console (1.0 - 2008-08-18)

POST single binary file:
/{a}/{c}/{e} "[c:][\folder\path\]file.ext" ["mime-type"] [y]
where:
	{a} = authority
	{c} = container
	{e} = entity
	 y  = overwrite existing entities

ex:	/my-auth/files/my-profile "c:\temp\profile.jpg" "image\jpeg" y

POST multiple files using wildcard:
/{a}/{c}/* "[c:][\folder\path\]*.*" [y]

ex:	/my-authority/my-container/* "c:\uploads\*.*" y
	or
ex:	/my-authority/my-container/* "c:\images\*.png" y

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too.

Version 1.3 of Guestbook Client Demo Posted

2008-08-08

This update contains support for replies to posts and publishes RSS feeds for the public list and for each guest account. Several other small twekas have been done to improve the UI a bit, too.

Please visit the app, craete an account and post some messages. The more guests that sign up, the more I can test my coding and the SSDS datastore. Of course, all feedback is welcome on the SSDS Feedback page.

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too.

Version 1.0 of Guestbook Client Demo Posted

2008-07-31

This application is a simple 'guestbook' web app that allows users to leave messages for everyone to see. As an added feature, users must create an account in order to post messages. This allowed me to test out a cookie-based authentication pattern that mimics the HTTP Basic Auth pattern. That means that you can authenticate against this application using a browser-based cookie or by passing the same credentials via the HTTP Basic spec.

Another focus of this demo was using a single SSDS Container (guestbookthat holds multiple 'kinds' of Entity documents (guest and message). This means queries against the datastore need to make sure they get the correct entity type back. I am also interested in how performance will be affected using these more complicated queries to filter messages by guest, etc.

In addition, since the application could be updated quite frequently I did some work to make sure entity lists are cached by the local server using ETags. ETags are currently supported by SSDS, but only for single Entity objects, not for lists. Of course, it's not much of a challenge to *cache* the lists, it's the invalidation of the cached lists that offers the greatest challenge [grin].

Please visit the app, craete an account and post some messages. The more guests that sign up, the more I can test my coding and the SSDS datastore. Of course, all feedback is welcome on the SSDS Feedback page.

As usual, I released this demo app on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too.

Version 1.6 of Data Client Demo Posted

2008-07-21

This update has just a few minor UI tweaks. Also, it does a bit bertter job of caching (again). This will be the last release before the SSDS upgrade on 2008-07-25.

I also released this version (1.6) on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode space, too.

New SSDS.EXE Console App Posted

2008-07-18

This is a simple console app that you can use the interact with your SSDS data directly from the command line. This app talks direclty to my SSDS-Proxy application. Now, you can modify your SSDS data without even firing up a Web browser. A side benefit of this command-line app is that you can now write batch scripts to talk to SSDS data. Here's an example script that I included in the download ZIP: 

@echo off
rem script ssds console 

set authority=your-authority
ssds get    /%authority%
ssds post   /%authority%/fish
ssds get    /%authority%/fish
ssds post   /%authority%/fish/ fish-001.xml
ssds post   /%authority%/fish/ fish-002.xml
ssds get    /%authority%/fish/ 
ssds get    /%authority%/fish/fish-001 
ssds delete /%authority%/fish/fish-002
ssds get    /%authority%/fish/
set authority=

I also released this demo as part of my SSDS Examples collection on the CodePlex website under SSDS Examples. The same code can be found at my GoogleCode SVN space, too.

Version 1.4 of Data Client Demo Released w/ refactored Javascript code

2008-07-14

This release has only a few new bits of functionality: added "Refresh" buttons for Containers and Entities lists; links to the Feedback page; better error messages. The real work in this update was behind the scenes. The Javascript class (provision.js) has been completely rewritten. It should now be easier to maintain and easier to read, too.

I also released this version (1.4) on the CodePlex website under SSDS Examples. The same code can be found at my SVN code space, too.

For those who are watching this project, I plan on another update soon that will change the URI pattern for the calls to the SSDS proxy server. In fact, I suspect I'll publish a clean SSDS Proxy API (REST) in the next week or so. That will allow others to start writing their clients against the same proxy, if they like.

Version 1.3 of Data Client Demo Released - now with Caching!

2008-07-10

In anticipation of caching support in the upcoming SSDS 'Sprint 3' release, I added caching to my SSDS Proxy (the server code behind the SSDS Client demo app). Now, GETS are cached at the server to reduce traffic between the SSDS Proxy and the remote SSDS server. This also cuts down on trasffic between the client apps and the SSDS Proxy. Currently, there'a bit more traffic betweeen SSDS Proxy and the SSDS servers since SSDS server do not yet support caching. Once they add support for ETag and If-Match headers, traffic between the proxy and SSDS will decrease even more.

A nice side-effect of implementing caching support (via ETags) is that the proxy can now implement a fix for the Lost Update Problem. Now, when multiple users are editing the same document, no-one's edits will get 'clobbered' by another user's updates. That's because the ETag header value returned via HTTP GET needs to be sent with the updated document as the If-Match header value when making an HTTP PUT to the server. If the headers do not match, the server assumes someone else has updated the document and refuses to complete the PUT. It takes a bit of planning to implement on the client but once you have it, your users will be much happier!

You can view the source and download the latest code from my SVN code space. Feel free to send me feedback via email:

Data Client Demo Updated

2008-07-08

I updated the Provisioning Demo. The SSDS Provisioning Client now supports a simple Entity query interface. Once you select your Authority and Container, you can enter any valid SSDS query and see the resulting filtered list. I also did a little UI clean-up including an alert to remind you to login before you begin executing commands.

You can view the source and download the latest code from my SVN code space. Feel free to send me feedback via email:

Data Client Demo

2008-07-04

I updated the SSDS Data Client code today and IE should now work as expected. If you see any problems, feel free to send an email to:.

I posted a new demo application here today. The SSDS Provisioning Client allows you to manage all your SSDS Authorities, Containers, and Entities via a simple (quirky?) Web UI. This was build to explore the details of managing SSDS objects via the REST interface. All requests from the Ajax client go directly to an SSDS Proxy server which interprets the data and then makes calls to the remote SSDS servers on your behalf.

This web application requires you to login with your SSDS username and password. Since this is a public web app hosted via HTTP (not HTTPS), you may not want to use the live version of the app. Instead, download the source code and host the application on your own local server.

One of the interesting features of this application is that it contains code for generating unqiue (Ascending or Descending) IDs for Entity objects. Some of this was discussed on a recent SSDS Forum thread.

The current code is fairly solid, but will probably be updated as the SSDS beta progresses. I'll keep tweaking it and posting results to the SVN code space. Feel free to send me feedback via email:

TaskList Demo

2008-06-23

I posted the Tasklist Demo today. You can check out a simple HTML web client to see how it all works. You can also ping the rasw XML data in the SSDS repository via the SSDS Proxy server (built using C#). Finally, you can check out the source code for both projects at my google code site.

The current code is pretty 'rangy.' Not quite ready for a live demo. But it all works. I'll keep tweaking it and posting results to the SVN space. Feel free to send me feedback via email: