SSRS Data-Driven Subscription [based on static Subscription table] Not Picking Up Changes Made to Subscription Table

Question

I have a .RDL report which I designed in BIDS and have deployed to my report server. The report asks for three parameters before viewing report: Year , Month and Customer ID . The report works great and does exactly what it is supposed to.

While I used to run each report individually because there were 2-3 customers, now there are 30+ customers who receive the report, so I wanted to switch to a more automated fulfillment method to get the reports generated. After doing some research it appears that a using Report Manager to create a "Data Driven Subscription" (DDS) using the "Windows File Share" option gives me the capabilities I need.

As part of creating the DDS, I created a table called [Subscription] which is a table containing one row for each customer receiving the report and has the following columns:

• Year
• Month
• CustomerID
• FileName
• FileLocation
• Overwrite
• Format

...so through using the DDS Wizard in Report Manager, I was able to successfully set up a Data Driven Subscription (which is linked to various columns in the [Subscription] table) which creates a new report for each customer in the [Subscription] table, saves [and overwrites, if necessary] it in a location of my choosing as a PDF (specified in [Subscription].[FileLocation] , or the FileLocation column of my table for each row), and runs every minute (I plan on changing frequency to once a week, eventually).

This works flawlessly, giving me a new set of 30 reports in the directory of my choosing, with each report having a name I assigned in the FileName column of my table. Exactly what I was looking for.

HERE'S THE PROBLEM: When I update the FileLocation or FileName (or anything, really) in the [Subscription] table - it doesn't pick up the changes right away. Sometimes it doesn't even pick it up at all (for example I updated the [ReportName] column for one customer from Report_711622 to SpecialReport_711622 , so that the output file for that customer should be named SpecialReport_711622 while all of the other reports should be called Report_XXXXX [no Special prefix]. But the file name of report for Customer 711622 remains the same!

It's almost like the job only see's what it needs to do once a day, and then does not go back and reference the [Subscription] table until I leave for the night, then when I come back in the morning it picks up the change.

Since I am about to scale this process out to a large customer-base using a different report, I need to be able to make edits to the [Subscription] table and have them get picked up by the Data Driven Subscription immediately (and if not immediately, at least a fixed interval of time that I can adjust, so that I can know 100% when the change will get picked up).

Does anyone know what's causing my lag? How do I change it so that updates to the Subscription table get picked up regularly? I'm also having issues with creating new DDS on other reports (following the exact process outlined above) - I've created the subscriptions, for every minute, and it says they are running and the number of outputs match the number of customers with 0 errors, but there are no files in the drive I specified (or anywhere else I've looked, for that matter).

Any help would be greatly appreciated!

Answer 1

I think the answer lies in the mechanism SSRS uses. There are a few places "lag" can occur.

The subscription is in fact an SQL Agent job which creates a record in the Event table. This table is a queue that SSRS checks to do scheduled tasks.

There is a small amount of time between the moment the subscription creates the Event record and the moment SQL reads it and starts creating the dataset for your DDS. The creation of the DDS dataset takes some time, too. In this time, the subscription will be in the Pending state. If you change anything in the data during this time, The subscription will still use the old data as report parameters. So obviously you will not notice your change until the next scheduled run.

Which brings me to the following: if a subscription is still being run and the next schedule kicks in (chances are, because yours runs every minute), the engine will not execute it, but wait for the next subscription schedule, and so on. So that's another possibility of lag - and cause of missing reports for a certain schedule minute. The subscription processes reports sequentially, one row from your DDS recordset at a time. Again, this takes some time. You can also see that in the subscription window when it says: # of # processed.

I suggest you look at the Event table in the database ReportServer during an execution. Also the ExecutionHistory views (there are 3) may be interesting. A scheduled run shows up as a RequestType = 1 and generates one record for each report. You can see the exact timing and parameters of each report that is run in the subscription. You may be able to extract the data you need to resolve your other issues.

EDIT: Here is a more elaborate guide to DDS data and events http://blogs.msdn.com/b/deanka/archive/2009/01/13/diagnosing-and-troubleshooting-subscriptions.aspx http://blogs.msdn.com/b/deanka/archive/2010/02/16/troubleshooting-subscriptions-part-ii-using-the-report-services-trace-log-file.aspx

Answer 2

Could this "Double-Hop" problem be the source of my issues? I'm so stuck on this one! The Double-Hop Problem - MSDN Knowledgecast