The case of the Inventory gotcha with Azure SQL and Sitecore Commerce 8.2.1

I only recently discovered comments to this blog were going into an unmonitored spam folder — my apologies if anybody had their hearts set on a response to their comment!  In scanning some of those comments, I thought a proper response was warranted to one note on a piece I wrote about a hard to find Sitecore Commerce configuration setting.

I started that post by writing:

After recently swapping the backing store from Azure SQL to SQL Server (due to an interesting Inventory gotcha with the Reference Storefront that I’ll maybe share at some other time), I’m finding nooks and crannies of configuration I never knew existed with the Commerce product until now.

This post discusses the interesting Inventory gotcha with the Sitecore Commerce storefront implementation. I should point out this is relevant to Sitecore Commerce 8 and I’ve not tested this specifically with Sitecore Commerce 9, but I assume it’s been addressed in version 9 by either not using the same Reference Storefront for Commerce (in version 9 you’d be steered to an SXA UI instead of the older “Reference Storefront”) or by the general platform improvements in Sitecore Commerce 9.  I guess you can stay tuned for Sitecore Commerce 9 news on this front!

The Problem Scenario

This is IaaS VMs running Sitecore 8 (conventional IIS, not PaaS) and using the Sitecore Commerce 8.2.1 release in a scaled Sitecore environment. Azure SQL was chosen as the database technology for a variety of reasons I need not go into. This implementation used separate Commerce catalogs for CM servers and CD servers, to provide the “publish workflow” behavior Sitecore uses for marketing content; this is accomplished for Commerce via the Staging Service.

One tricky area when using multiple Commerce catalogs is Inventory. A late-breaking customer requirement was the need for inventory updates to flow real-time between content management and content delivery servers, so nobody sees stale inventory data. Don’t you love those late-breaking customer requirements?

This can be handled in different ways, but the method appropriate to this project was to use a single Inventory database that both Sitecore CM and CD environments would reference for inventory data.  Commerce Server Manager presents this in the UI as the “Inventory” resource under the Commerce site:

It’s smart to have separate databases for product catalog and inventory, and we set this solution up to have multiple catalogs (one for CM and one for CD) with a shared Inventory database so that data was always realtime.

The crux of the problem was the mechanism Sitecore’s Reference Storefront uses to coordinate Inventory queries between the two Commerce catalog databases — it’s called Cross Database Query and it’s not supported the same way in Azure SQL as it is in conventional SQL Server.  You can do cross database queries with Azure SQL, just not the way the Reference Storefront for Sitecore Commerce depends on it.

The exception we would see was as follows:

SqlException (0x80131904): Reference to database and/or server name in ‘CFSolutionStorefrontSite_productcatalog.dbo.Habitat_Inventory_InventorySkus’ is not supported in this version of SQL Server.

The above was followed by a fair amount of StackTrace such as:

System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +3189408
 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +753
 System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +5042
 System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() +87
 System.Data.SqlClient.SqlDataReader.get_MetaData() +101
 System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString, Boolean isInternal, Boolean forDescribeParameterEncryption) +590

You get the idea.

What We Considered

After considering our Sitecore Commerce configuration and confirming it was solid, the exception next had us examining Azure SQL compatibility settings, but that wasn’t the issue.

We determined we could do an import/export of Inventory data.  Maybe the Sitecore publish:end event could push inventory changes to the CD servers, where they store inventory in an XML file and on publish:end:remote we could import that XML data into the Content Delivery servers.

We could remove publishing from the equation and use a scheduled <agent> to move Inventory data around.

What We Actually Did

The import/export options were never going to be truly realtime, at least not sufficiently “real” for our project and their inventory requirements. So we swapped out the database back-end and used SQL Server in IaaS VMs instead. Cross database query worked as expected, and we could use a central Inventory database with multiple Commerce Catalog databases for CM and CD sites. It worked as it should.

This concludes the tale of the interesting Inventory gotcha around Sitecore Commerce 8.2.1 — this should close the loop with the initial post from a few months ago, I hope this helps out somebody else!

Sitecore Commerce 8.2.1 Firewalls & Azure SQL Notes

I know Sitecore Commerce 9 is just around the corner, but I know many projects are under way with the current Sitecore Commerce 8.2.1 and I wanted to share some notes we’ve collected on how to work with the technology.

This is from lessons our team at Rackspace has collected, including some exceptionally talented “sales weasels” who have really dug into the Commerce platform with us to determine perf benchmarcks etc — score 1 for the talented sales weasels ξ(^◒^)ξ !

These two links are the key pillars of online documentation for getting started with the product:

http://commercesdn.sitecore.net/SitecoreCommerce/DeploymentGuide/en-us/index.html

http://commercesdn.sitecore.net/SitecoreCommerce/DevOpsGuide/en-us/index.html

As a complement to the above, I’d like to share the following tips we’ve learned on a few Sitecore Commerce 8.2.1 projects . . .

Firewall Settings

We’ve run into issues with both the Sitecore Commerce Staging software and the Profile system; the exceptions are logged to the Windows Event log or the Sitecore logs and can report an ugly COM error such as the following . . .

Don’t panic

. . . it turns out that the current documentation doesn’t mention Firewall rules for these two services to operate.  After some investigation we realized we needed to open up ports.  Prior versions of Sitecore Commerce have this article, http://commercesdn.sitecore.net/SCpbCS82/SitecoreCommerceDeploymentGuide/en-us/FirewallPorts.html, and it turns out port ranges 5000-5030 and 507 can be important to proper communications in a distributed Sitecore Comemrce build.

Azure SQL

Everyone is price conscious and Azure SQL can save customers a lot of money over conventional SQL Server.  Documentation online for 8.2 states Azure SQL is supported, but the installation documentation doesn’t treat it as a first-class citizen.  There is this great link, http://commercesdn.sitecore.net/SCpbCS81/SitecoreCommerceDeploymentGuide/en-us/c_UsingAzureSQLwithCS.html, with notes on Azure SQL specific provisioning for Sitecore Commerce — but it’s organized under a PaaS installation topic which hides it from our IaaS Sitecore Commerce eyes.

Generally speaking, the Initialize-CSSite script modifies the SQL database schemas and does not work if you use Azure SQL.  The authentication assumptions are invalid (using an App Pool user isn’t going to fly with Azure SQL).

This can be worked around (mostly), but we learned the hard way that the Sitecore Commerce Reference Storefront application is not compatible with Azure SQL in the reliance on Cross-Database queries for certain key operations; in our case, trying to use a central Commerce Inventory Azure SQL database was ultimately untenable.  Azure SQL does offer Cross-Database queries, but the syntax is different and the Reference Storefront code has non-trivial dependencies on the IaaS SQL Server understanding of querying between databases.

There are a lot of nooks and crannies with Sitecore Commerce 8.2.1.  I know everyone is excited about a fresh start with Sitecore Commerce 9 that doesn’t include the legacy COM and thick-client dependencies; this write-up summarizes a few of the Commerce highlights on the horizon.  For now, however, there are Commerce 8.2.1 builds in the wild that require our attention and I hope the above notes help others to be successful.

The Odyssey of Sitecore Commerce Staging’s Reliance on SQL CE 3.5

The Problem

I recently completed a fun journey triaging a set of self-inflicted wounds around Sitecore Commerce Staging.  The rest of Sitecore Commerce 8.2.1 ran as expected except for when I setup the Sitecore Commerce Staging between a CM and CD tier . . . I would get an odd “The system cannot find the file specified” dialog box immediately after trying to start a basic Staging replication project:

And when I say that pop-up appears immediately after clicking the “Start Replication” button, I mean it — we’re talking almost instantaneously.

Background

I’ll pause here just to lay out why one cares about Commerce Server Staging with Sitecore.  The Commerce Staging documentation is on MSDN in a variety of places, and Sitecore is using this sub-system to manage Commerce specific content promotion (such as product catalog changes, promotion codes, etc).  As explained in the summary on CommerceSDN.Sitecore.net :

The role of Commerce Server Staging is to move Commerce Server data between environments or sites.

If the master and web environments are pointing to the same Commerce Server site instance, as soon as data is changed on the master environment, it will be published to web. To ensure that Commerce Server data is not published unexpectedly, it is strongly recommended that you have one Commerce Server site for your Content Management (CM) environment, a separate Commerce Server site for your Content Delivery (CD) environment, and then use Commerce Server [Staging] to move the data.

I added the [Staging] to the final sentence above, as I think it’s pretty key to understanding the topic.

Commerce Server Staging is the vehicle one uses to manage Commerce data the same way we manage marketing data in the rest of Sitecore.  We create and update Sitecore CMS content in a “master” SQL Server database and then promote it to “web” with a Sitecore Publish operation . . . then we create and update Sitecore commerce content via the Sitecore CM and promote changes to the live website via Sitecore Staging operations.  The Sitecore Publish process has been extended with Sitecore Commerce to include Staging, so you can run it as a single integrated process.  Note the “Commerce Server Staging” checkbox included in the Sitecore Publish dialog below:

It’s usually magic and just works — but I was not able to run any type of Commerce Staging operation, so I needed to peel back the curtain and learn a bit more about how to troubleshoot Commerce Staging.

The Solution

This write-up on Monitoring Commerce Staging laid the foundation for my eventual resolution.  Before exploring that angle, however, I reviewed this write-up with some basic pitfalls on Commerce Staging . . . of course there’s this gem about DCOM permissions (& my write-up on applying that setting when the GUID isn’t readily available) . . . Sitecore’s KB site has some suggestions and the Community.Sitecore.net has some suggestions. There are hundreds of nooks and crannies one can investigate here, so it took me some time to discover what was going on.  Hopefully, my adventure can inform others, so here goes . . .

1. The link about monitoring Commerce Staging (https://msdn.microsoft.com/en-us/library/ms961837(v=cs.70).aspx) talks about ways to configure what is logged and how to view the events of the Staging process.  I digested this info and, while the write-up assumes some old IIS configurations, I discovered the C:\Program Files (x86)\Commerce Server 11\Staging directory has two folders of particular interest to me: Data and Events.  The Events folder has .mdb and .ldb files (yes, that’s Microsoft Access) that form a type of localized Event Log for Commerce Staging; the Data folder has a StagingLog.sdf file — .sdf is a format used by SQL Server Compact Edition
2. I opened the Access database and found that it didn’t have any helpful information for my scenario.  My “cannot find the file specified” exception was not in evidence there . . . but there is some interesting meta-data captured in that Access MDB for Staging.  This Events folder appeared to be a dead-end.
3. I used LinqPad to analyze the StagingLog.sdf file (turns out Commerce Staging uses SQL CE 3.5 edition), and I learned two key things:
   • This StagingLog.sdf file was essentially empty — no data was being written to it when I tried to start a Commerce Staging operation
   • I couldn’t use LINQPad on the server running Commerce Staging as I didn’t have the proper SQL CE 3.5 drivers, but when I moved it to my developer machine I could view the .sdf file without issue.  Interesting . . .
4. My next step was to use ProcMon (available at https://docs.microsoft.com/en-us/sysinternals/downloads/procmon) and compare a process capture from my environment that raised the exception with a properly functioning Commerce Staging environment.  This took some trial and error, but filtering on the CSSsrv.exe helped me focus on the task at hand.
   • The properly functioning Staging environment had a lot of activity with the StagingLog.sdf file.  We’re talking hundreds of operations.  The broken Staging environment had none.  Once I tracked ProcMon instruction sets 1:1 between the two environments I found the final piece of evidence I needed:

The highlighted area above, C:\Program Files (x86)\Microsoft SQL Server Compact Edition\v3.5\sqlceer35EN.dll entries, were entirely missing from the initialization process of my broken Commerce Staging environment.

The lightbulbs finally went off for me, and I did a quick comparison of the C:\Program Files (x86) directories of the two servers.  There were key components missing from the environment where Staging wasn’t working, and it revolved around SQL Server Compact Edition.  Here’s a highlight showing what obviously wasn’t on the server in question:

Neither MS SQL Server Compact Edition nor MS Synchronization Services were installed to this server.  I did some further research, and learned that the CommerceServer.exe should fold in these elements with any Commerce install, so I needed to do a repair installation with the CommerceServer.exe and that added SQL Server CE and other dependencies necessary to solve the issue.

Our PowerShell that installs the CommerceServer.exe must not have been using a properly elevated account, or this was done with a manual execution of the installer that didn’t use the proper administrative credentials.  Everything worked fine after I completed the repair install of Commerce Server.

There are some additional items to point out here:

• Based on my testing, the CommerceServer.exe may exclude some key Staging dependencies if it’s not run in a proper Administrator context.  I thought it was written in the docs somewhere, but I don’t see it in Sitecore’s documentation on installing Commerce Server .exe — running that EXE in the context of a local admin account is crucial to the success of that process.  I use this account and the shift + right-click -> Run as different user” option when launching the CommerceServer.exe manually, and this has been successful for me.
• If you’re like me, and love the post-script to a good story,  here’s what LINQPad shows for that StagingLog.sdf once you’ve run a couple successful Staging operations:

• I think additional take aways from this write-up are:
  • there’s an MS Access database in C:\Program Files (x86)\Commerce Server 11\Staging\Events that could be a source of interesting diagnostic info on your Sitecore Commerce Staging activities
  • there’s an SQL CE database in C:\Program Files (x86)\Commerce Server 11\Staging\Data that could be a source of interesting diagnostic info on your Sitecore Commerce Staging activities