Instrumenting, Monitoring and Auditing of SSIS ETL Solutions SQL Bits Manchester Davide Mauri

EXEC sp_help ‘Davide Mauri’ MCDBA, MCAD, MCT Microsoft SQL Server MVP Works with SQL Server from 6.5 Works on BI from 2003 President of UGISS (Italian SQL Server UG) Solid Quality Mentors –Italian Subsidiary

Agenda ETL Story Logging SSIS in MS way Workarounds Logging SSIS in MY way –The developer’s corner Adding value to log data 3 © 2007 Solid Quality Mentors

ETL Story 4

ETL process grows in complexity Since package won’t be run from BIDS in production you need something to help to understand –What went wrong when package didn’t worked as expected And maybe this happens only at nighttime… –Monitor the performance of your package to forecast its ability to stay within a given timeframe 5

Logging SSIS in MS way Flexibility –You can decide what and where to log to –You have a lot of ready-to-be-used log providers –Is available out-of-the-box Well, you have to remember to activate it Nice things 6

Logging SSIS in MS way Logging needs to be set up within the package –If you need to change logging you need to edit the package in VS Too few information given –No Variables values –No Expressions results –No Information on Data Flow –Cannot handle very well chains of packages (>=2) Problems using Parent Package Variables to propagate logging configuration (eg: log file path) You just lose information when you have more than 2 packages in the chain Not-so-nice things 7

Logging SSIS in MS way DTExec seems to allow to control logging at runtime –Unfortunately you need to have a properly configured connection manager in advance Things that don’t work as expected  8

Logging SSIS in MS way Some new features added with SQL 2008 –SQLDumper Too much detailed information on one hand, and again to few on the other “Improved” things from 2005 to

Logging SSIS in MS way Doesn’t really offer an help to understand what’s went wrong –To few information given Hey, I’d like to log also Data Flow! I really have to do everything by hand? –This can take a lot of time! I want to change my logged data. How can I do it without have to open the package in BIDS and release-test-deploy it? –You can’t! Conclusions 10

Logging SSIS in MS way Use specific task (Script, Custom or Execute SQL) before and after each task you want to instrument Create an event-handler for each event you want to log (es: PreExecute, PostExecute) –Better if then you use a tool to create SSIS templates and standardize them Like MDDE (Metadata-driven ETL) – Workarounds 11

Logging SSIS in MS way DEMO 1. The usual way 12

Logging SSIS in MY way Basically I’d like to have all the information that BIDS give you, but outside BIDS. Now, if BIDS can, WE can –No magic here, just need to know the APIs! Just a little bit complex…but we’ll simplify things here The key is the Execute method of Package class –In particular the overloads that takes the IDtsEvent interface parameter Whose documentation is not very rich Learn from BIDS 13

Logging SSIS in MY way IDtsEvents is implemented by the base class DefaultEvents We have to create a custom event handler class deriving from DefaultEvents and then override all default event handlers Use an instance of the newly created class as a parameter for the Execute method on Package object –Now all events will be intercepted by our Event Handler! Developer’s corner 14

Logging SSIS in MY way The event handlers methods can call a custom method to log data –Beware! SSIS runtime make heavy use of threads –We have to deal with the fact that our class is used by different thread at the same time. We have to be sure that race conditions cannot occur We have to be fast to avoid to impact too much on performances –Log the minimum for all event except errors –Log everything we can for error They should never happen Developer’s corner 15

Logging SSIS in MY way All containers will raise events Inside each event handler method we can access to all runtime information for that container –Variables –Connections –Configurations –Properties And their expressions Developer’s corner 16

Logging SSIS in MY way Variables: use the Variables collection available in each container Connections: use ConnectionManagers collection available in Package class Configurations: use Configuration collection in Package class –The EnableConfiguration property also tells you if a Package will try to look for “default” configurations Developer’s corner 17

Logging SSIS in MY way Extracting properties is a bit tricky… –First we have to ask to the container its properties through the Properties collection of the IDTSPropertiesProvider interface –For each property we have to call the GetValue on the Property passing the object from which this property come from as a parameter (!!!) Developer’s corner 18

Logging SSIS in MY way Now, for Control Flow, we’re done. What about Data Flows? No specific native logging infrastructure...but BIDS is able to show us how may rows flows between components –…so these information are available somewhere! DataFlow is able to generate events through the FireCustomEvent method Developer’s corner 19

Logging SSIS in MY way Custom events are described by the EventInfo class –Every container has an EventInfos property (a collection of EventInfo) The key event here is the “OnPipelineRowsSent” data flow custom event –Here we have an array of objects that contains interesting things For this event the array contains 8 entries Developer’s corner 20

Logging SSIS in MY way OnPipilineRowSent payload –Source Object (eg: System.__ComObject) –DataFlow Object ID (eg: 140) –DataFlow Object Name (eg: OLE DB Source Output) –Object ID (eg: 134) –Object Name (eg: TransformationName) –Input Object Id (eg: 135) –Input Object Name (eg: Derived Column Input) –Row Count (eg: 744) Not documented in EventInfo Developer’s corner 21

Logging SSIS in MY way So, filtering on Custom Events we’re able to profile the entire DataFlow! –On buffer basis We can also count how many times a DataFlow has been invoked when placed into a For..Loop or For..Each container –Together with the knowledge of variables values this provide us information the impact of each iteration Developer’s corner 22

Logging SSIS in MY way DEMO 2. Show me the code! 23

Logging SSIS in MY way The result is DTLoggedExec –Current version beta Log everything needed –Package version –Variables values –Properties’ Expressions –Profile Dataflow DTLoggedExec 24

Logging SSIS in MY way Additional Features –Handle long package chains correctly –Supports the majority of DTExec options –Pluggable architecture Easy to create custom Log Providers In future will also be able to add custom Data Flows Profilers Supported platforms –Every platforms & architectures are supported 2005, 2008 X86, X64, IA64 DTLoggedExec 25

Logging SSIS in MY way DEMO 3. Test it! 26

Logging SSIS in MY way Profiled data from DataFlows packages can be huge…better to put it into a database With DTLoggedExec comes a full set of scripts and batch to create a specific database and to bulk load data –Actually only data profiled from DataFlows can be imported –In near future also data from CSV log provider will have its place here 99% done, testing in progress DTLoggedExec DB 27

Logging SSIS in MY way DEMO 4. Load profiled data 28

Logging SSIS in MY way Control Flow –Performance are affected by the amount of logging you decide to have Data Flow –Impact of performing dataflow profiling: < 5% DTLoggedExec can be improved to have even less impact if needed –Better buffering Performances ? 29

Logging SSIS in MY way DTLoggedExec is under Creative Commons license –Anyone can contribute Official homepage – –Wiki with documentation Download, source code, issues and forum – Support 30

Adding value “Native” Auditing –When, who and how a row has been imported in my DWH? Performance monitoring of a single package –Or Dataflow Performance monitoring over time Easy to monitor discarded rows –Very useful in dashboard Monitor SLA 31

Logging SSIS in MY way DEMO 5. Adding value 32

Question & Answers DTLoggedExec

References DTLoggedExec – Jamie Thomson, “Custom Logging Using Event Handlers” – 05/06/11/SSIS_3A00_-Custom-Logging-Using-Event- Handlers.aspxhttp://blogs.conchango.com/jamiethomson/archive/20 05/06/11/SSIS_3A00_-Custom-Logging-Using-Event- Handlers.aspx Andy Leonard, “ETL Instrumentation” – TL+Instrumentation/default.aspxhttp://sqlblog.com/blogs/andy_leonard/archive/tags/E TL+Instrumentation/default.aspx 34

Thanks! DTLoggedExec 35