Tag Archives: logging

Free download: Blog Yearbook 2016

I have made a compilation of all my blog posts of the past year, and it was more work than you would think.
Especially because it also contains a non-published new article.

After filling in the form you can download the e-book for free.

I promise you the following:

  • I will not give or sell your email address to any third party.
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(c) 2016 hansmichiels.com – Do not steal the contents – spread the link instead – thank you.

Implement logging in a Script Task (SSIS Series)

Introduction

This post is a follow-up on two older posts and will be the last one before my summer break.

Today I want to enhance the SSIS package made in post Fixing corrupt csv files in a SSIS Package (SSIS Series) by using the Plug and Play Logging Solution.

Problem

As long as a script runs well, you might not need logging inside. BUT .. when something GOES wrong, having logging in the script can reduce the time needed to troubleshoot the issue.
In the example for fixing csv files, anything can be wrong with a file, causing an error in the script. In that case it is for instance useful to know which file was being processed when the error occurred.

Prerequisite

For this to work, you have to install my Plug and Play Logging Solution, which can be downloaded from this post. It is just one SQL Script you have to run, that creates a [logdb] database with objects inside. You can also add those objects to a different database that already exists.
It is however not mandatory to rebuild the Fixing corrupt csv files in a SSIS Package example, as you can also add logging to your own Script Task.

Solution

This post is a enhancement on the Fixing corrupt csv files in a SSIS Package post, so you might need to read that post first, if you did not do that already.

Therefore I will dive directly into the changes that are needed to add logging in the Script Task.
This will be done with lots of screenprints with some comment in between.

SSIS-S01E07-169Adding a package parameter “LoggingConnectionString”
First you need to add a package parameter LoggingConnectionString that can be used in an expression of the OLE DB Connection and as input variable for the Script Task.

SSIS-S01E07-170OLE DB Connection configuration ..
Then add an OLE DB Connection for the logging database.

SSIS-S01E07-171OLE DB Connection properties ..
Use an expression to let the ConnectionString of the OLE DB Connection be equal to the value of the package parameter LoggingConnectionString.

SSIS-S01E07-173OLE DB Connection – Expression configuration [1]

SSIS-S01E07-172OLE DB Connection – Expression configuration [2]

SSIS-S01E07-174Final result
By the fx icon you can see that the connection manager uses an expression.

SSIS-S01E07-176Enable logging
Now enable logging for the package.

SSIS-S01E07-177Enable logging [2]
Add a log provider for SQL Server and let it use the logdb.oledbConnection by selecting it under the Configuration column header.

SSIS-S01E07-178Enable logging [3]
Then select all events. Filtering on what is actually logged is done by the logging solution (by the value of @MaxMessageClass, see this blog post for more details).

SSIS-S01E07-179Select the Script Task
Select the Script Task and add the following Variables to ReadOnlyVariables:

  • System::ExecutionInstanceGUID
  • System::PackageID
  • $Package::LoggingConnectionString


  • SSIS-S01E07-180The added ReadOnlyVariables in the red rectangles

    Below you will find a number of screenprints of the script task to talk you through the changes.
    You can download the C# script here.

    SSIS-S01E07-181Overview
    First make sure the Namespaces region is as shown.
    Then fold the namespace with the guid in the name, and paste the entire namespace HansMichielsCom.PlugAndPlaySSISLoggingSolution underneath it.
    This code is put in a separate namespace, so that it could also be placed in a .NET assembly that is added to the GAC (Global Assembly Cache). When you would do this, you do not have to add the code to every Script Task.
    For the example of today, we just put this namespace inside the Script Task to make things not too complicated for now.

    SSIS-S01E07-182Using the HansMichielsCom.PlugAndPlaySSISLoggingSolution namespace
    As a result, you have to tell the first guid-like namespace, that you want to call code inside the second namespace. Therefore add the using statement as shown above.

    SSIS-S01E07-183Constant used for logging
    Below you will see some printscreens with changed parts in the script.

    SSIS-S01E07-184Method GetSsisLogWriter to instantiate a SsisLogWriter object

    SSIS-S01E07-187Method Main is extended with logging.

    SSIS-S01E07-188Pass the logWriter as parameter to other methods ..

    SSIS-S01E07-189IMPORTANT: Bugfix in CheckAndReturnHeader!

    SSIS-S01E07-190IMPORTANT: Bugfix in CheckAndReturnHeader!
    (header == null) is added to cope with empty files.

    Testing, testing, one, two ..



    SSIS-S01E07-191Test preparations [1]

    SSIS-S01E07-193Test preparations [2]

    SSIS-S01E07-194Test execution

    SSIS-S01E07-195Test result: logging rows done inside the script are in the log table.

    Conclusion / Wrap up

    In this post I have demonstrated how to implement logging in SSIS Script Tasks using my Plug and Play Logging Solution.
    This type of logging gives more control on what to log and how to log it than when you implement logging using SSIS events.
    The examples given are very basic. You can use your imagination to implement logging of errors using a try .. catch block, or use all available parameters of logWriter.AddLogEntry to change the Retention Class, Message Class, and so on.

    In the summer I will take some time for study, reflection, holiday, and still .. work.
    My next post will be early September at the latest, maybe earlier.

    Download the C# script here.

    (c) 2016 hansmichiels.com – Do not steal the contents – spread the link instead – thank you.

A Plug and Play Logging Solution (SSIS Series)

Introduction

Ever had to investigate an error that occurred during execution of a SSIS package? Then you will know that logging is the key to know what happened.

And not only logging in SSIS itself, but also in stored procedures, c# script tasks, c# console applications you might have written and are executed from within the package.
SSIS-S01E01-log-story
So the log tells you a story (I once heard “so it reads like a thrilling boys’ book”, I liked that expression, GJ).

Also you do not want to reinvent the wheel for every SSIS project, but want to use a standard solution. Plug and Play instead of spending sprints on “utitilies”.

Feature list

The features in short (as compared with what SSIS offers out of the box):

  1. It’s a Plug And Play SSIS Logging Solution in most cases: no additional programming in SSIS Packages is required*), so can be easily used for all existing packages! Only when you have multiple master packages with the same name, you will have to do a little of set up work.
  2. Log messages are labeled with a message class (a sort of severity of the message) for easy filtering.
  3. Changing the maximum message class to log is possible without redeploying any SSIS Packages (for instance enable VERBOSE logging for trouble shooting, then set it back to DEBUG or INFO).
  4. Log messages are labeled with a retention class for easy purging. There is also an “audit” retention class for messages that may never be purged/deleted.
  5. Purging can be automated, so no scheduling is needed.
  6. Logging is Integrated/centralized for SSIS Packages, stored procedures and other home made software.
  7. Deduplicated logging can be enabled, if this is done, identical SSIS logging messages (e.g. first from the OLE DB Destination, then from the Data Flow Task, and then from the SSIS Package) are logged only once as much as possible.
  8. Master / child relations for SSIS packages can be configured, so that log entries from master- and childpackages can be retrieved easily together in a single timeline. Out of the box this works using a naming convention (Master package must have “master” in the name) but can be fine tuned for every package that runs.
  9. Easy configuration by executing a stored procedure, to set retention periods, maximum log class, automatic purging on/off, deduplicated logging on/off, and naming convention for the master package.
  10. Storage of both start- and endtimes of the current timezone as well as UTC start- and endtimes.

*) As far as the logging that SSIS does is concerned. If you want logging in your own stored procedures and executables you need to implement it first.

Quick Start Guide

  1. Download the installation solution script here.
  2. Execute the entire script to install on new database [logdb]. To install on existing database, skip the part of the script where the database is created and execute the rest against an existing database. All objects the solution creates are created in database schema [log] (except for stored procedure [dbo].[sp_ssis_addlogentry], this name is needed by SSIS).
  3. Enable logging in your SSIS Packages if you have not already done that. Use a logging provider for SQL Server and select all events for all components of the package (more details below).
  4. Configure the connection managers of your SSIS Packages to use the database in which you installed the solution. Alternatively you can execute the stored procedure [log].[spCreateCrossRefs] to redirect logging for existing packages to the logging solution without any changes in your SSIS packages. See the User Manual for more details.

Directly to User Manual

Steps to follow when you want to enable logging in your SSIS Package:

SSIS-S01E01-enable_logging

User Manual

Table Of Contents

Introduction

The “hansmichiels.com Plug And Play Logging Solution” provides Plug and Play logging for SSIS Packages, stored procedures and other home made software, like command line applications or web applications.
After installing the solution, as explained in the Quick Start Guide, you can manage the solution using a few stored procedures, or accept the default settings and run it out of the box.

Understanding MessageClass and RetentionClass

MessageClass can have one of these 6 values:

  • 1 = Fatal Error (SSIS OnError event)
  • 2 = Non-fatal error (reserved for user defined logging for non-fatal errors, not used by SSIS packages)
  • 3 = Warning (SSIS OnWarning event)
  • 4 = Info message (SSIS: PackageStart, PackageEnd, OnInformation events)
  • 5 = Debug message (SSIS: OnPreValidate, OnPostValidate, OnPreExecute, OnPostExecute events)
  • 6 = Verbose messages (SSIS: Pipeline, Diagnostic and OnProgress events, typically more than 90% of all SSIS log messages)

RetentionClass aligns with MessageClass because it also has values 1 to 6 and by default the RetentionClass will be equal to the MessageClass. However, when you do custom logging in your own stored procedures or executable programs, you can provide a different value for it, for instance MessageClass 4 (INFO) but RetentionClass 1 if you want the message to be kept longer than the value for RetentionClass 4.

In addition there is a RetentionClass 0 for messages that may never be purged/deleted.

There are two ways to prevent that log messages are purged/deleted:
  1. By setting the configuration setting @RetentionPeriodClassN (where N is from 1 to 6) to 0. Then ALL messages for that RetentionClass will never be purged. However when the configuration setting is changed to a different value, the next time spPurgeLog is executed, the messages can still be deleted.
  2. By explicitly adding log entries with RetentionClass 0. Those entries do not depend on configuration settings, and are never deleted, unless you delete them directly from the [log].[Entry] table.



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Understanding the stored procedures and user defined function of the solution

Stored procedure [log].[spConfigure]

With this stored procedure you can change a number of configuration settings which are parameters of the stored procedure.

SSIS-S01E01-configure
Configuration: a child can do the laundry

You only have to provide values for the configuration settings (parameters) that you want to change. Other settings will remain unchanged.

You can set the following parameters:

  • @ExecutionGuid: Guid used for logging the configure operation. Can be NULL.
  • @MaxMessageClass: The maximum MessageClass to log. For instance 5 means that log entries with MessageClass=6 (VERBOSE) are not logged. The defaultvalue is 5 (DEBUG).
  • @RetentionPeriodClass1: Hours to keep a log entry if the [RetentionClass] column has value 1. Set the value to 0 if the log message may never be deleted. The defaultvalue is 0.
  • @RetentionPeriodClass2: The same for [RetentionClass] = 2. The defaultvalue is 0.
  • @RetentionPeriodClass3: The same for [RetentionClass] = 3. The defaultvalue is 4320 hours or 180 days.
  • @RetentionPeriodClass4: The same for [RetentionClass] = 4. The defaultvalue is 2160 hours or 90 days.
  • @RetentionPeriodClass5: The same for [RetentionClass] = 5. The defaultvalue is 336 hours or 14 days.
  • @RetentionPeriodClass6: The same for [RetentionClass] = 6. The defaultvalue is 168 hours or 7 days. Verbose messages are typically more than 90% of all messages, so a short retention period is recommended, if logged at all.
  • @DefaultMasterSourcePattern: default naming convention for master packages. Use wildcard % for nameparts. The defaultvalue is ‘%Master%’.
  • @EnableAutoPurgeOnPackageEnd: If enabled, spPurgeLog will be executed every time a SSIS Package ends. This keeps the log clean without an additional effort for scheduling, but the downside is that spPurgeLog might be executed more often than when it is scheduled daily. This is not harmful, but could have a negative impact on package performance. The defaultvalue is 0 (false).
  • @EnableDeduplicatedLogging: If enabled a staging table [log].[EntryStaging] will be created and duplicate SSIS log messages (with different sources) will be deduplicated as much as possible. Still in some situations duplicates may occur but a lot less than when this setting is not enabled. The defaultvalue is 0 (false).
  • @ResetAllToDefaultValues: Use 1 to reset all values to the values of the DEFAULT constraints on the [log].[Config] table. In that case all other parameter values are ignored.

Examples of use:

EXECUTE [log].[spConfigure] @ResetAllToDefaultValues = 1;

EXECUTE [log].[spConfigure]
@EnableDeduplicatedLogging = 1,
@EnableAutoPurgeOnPackageEnd = 1,
@MaxMessageClass = 6,
@RetentionPeriodClass2 = 8640,
@RetentionPeriodClass6 = 48;



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Stored procedure [log].[spAddLogEntry]

You can use this stored procedure to implement logging in your own stored procedures or executable programs.

It is advised that your own stored procedures which are called from within SSIS Packages, have a parameter @ExecutionGuid (with datatype UNIQUEIDENTIFIER). Provide the value from the package variable System::ExecutionInstanceGUID.

You can set the following parameters:

  • @Event: The log event, can be NULL. If you leave it empty, the event name will be based on the value for @MessageClass.
  • @Source: The log source.
  • @SourceGuid:The log source guid, can be NULL.
  • @ExecutionGuid: A global unique identifier to be able to distinct log messages of different jobs running in parallel.
  • @StartTime: Can be NULL, if NULL the current date/time is used.
  • @EndTime: Can be NULL, if NULL the value of @StartTime is used (which can be set to current date/time).
  • @MessageClass: The MessageClass of the message: 1=Fatal Error, 2=Error, 3=Warning, 4=Info, 5=Debug, 6=Verbose
  • @RetentionClass: A numeric indicator for the time after which the log messages can be deleted or purged. Values align with MessageClass, and in addition there is a RetentionClass with value 0 for log messages that may never be deleted, e.g. for auditing purposes. Can be NULL, if NULL the value provided for MessageClass will be used.
  • @Message: The log message.

Examples of use:

— At the beginning of a stored procedure:
DECLARE @Source NVARCHAR(1024) = ‘log.spCreateCrossRefs’;
DECLARE @Message NVARCHAR(2048) = ‘Starting: ‘ + @Source;
EXECUTE [log].[spAddLogEntry] @Message = @Message, @ExecutionGuid = @ExecutionGuid,
@Source = @Source, @MessageClass = 4;

— at the end of a stored procedure:
SELECT @Message = ‘Finished: ‘ + @Source;
EXECUTE [log].[spAddLogEntry] @Message = @Message, @ExecutionGuid = @ExecutionGuid,
@Source = @Source, @MessageClass = 4;

— To log something specific:
SELECT @Message = ‘Purged ‘ + CAST(@RowCount AS NVARCHAR) + ‘ log entries with RetentionClass ‘ + CAST(@RetentionClass AS NVARCHAR) +‘.’;
EXECUTE [log].[spAddLogEntry] @Message = @Message, @ExecutionGuid = @ExecutionGuid,
@Source = @Source, @MessageClass = 4, @RetentionClass = 0;



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Stored procedure [log].[spPurgeLog]

Schedule the execution of this stored procedure daily when you do not want to set EnableAutoPurgeOnPackageEnd to 1 (true).

This stored procedure has a parameter @ExecutionGuid used for logging the purge operation, but you can omit the parameter, then a new unique identifier value will be used.


Example of use:



EXECUTE [log].[spPurgeLog]

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Stored procedure [log].[spCreateCrossRefs]

Stored procedure to create synonyms in a database and create or replace the stored procedure [dbo].[sp_ssis_addlogentry] (hereafter collectively called: the cross references)

Use this stored procedure for two purposes:

  1. If you want to do logging in your own stored procedures in the database specified with parameter @DatabaseName
  2. If you want to redirect logging for SSIS Packages that use the database specified with parameter @DatabaseName for logging. In this way those packages will use the logging solution without the need to change the connection string.

You can set the following parameters:

  • @ExecutionGuid: Guid used for logging the configure operation. Can be NULL.
  • @DatabaseName: the name of the database in which the cross references must be created.
  • @DebugMode: if 1, more details will be shown in the output window
  • @SimulationMode: if 1, only the SQL Statements are shown in the output window, but they are not executed.
  • @DropOnly: if 1, the cross references are only dropped, but not (re)created.



Example of use:

USE [logdb]
GO
EXECUTE [log].[spCreateCrossRefs]
    @DatabaseName = 'MyOtherDb'
  , @DebugMode = 1
  , @SimulationMode = 1
  , @DropOnly = 0
GO

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Stored procedure [log].[spSetMasterSourcePattern]

While packages run, the table [log].[Source] is filled with Source (= SSIS Package) and MasterSource information, based on the configuration setting @DefaultMasterSourcePattern.

If the value for @DefaultMasterSourcePattern is correct for all packages that run, you do not have to change anything.

However when the Master/child Source relations need to be changed, you can use stored procedure [log].[spSetMasterSourcePattern] to configure master- and child package relationships.

The definition of a master package is a package that executes another SSIS Package, the child package. When going more than one level deep, only the ultimate parent package (the one that starts everything else) has to be defined, the “package tree” is not relevant. For instance Package A executes Package B, and Package B executes Package C. In this situation A should be defined as master package for C.

You can set the following parameters:

  • @ExecutionGuid: Guid used for logging the configure operation. Can be NULL.
  • @Source: The log source or log source pattern. For a pattern use a % wildcard, e.g. “Load%” for all sources of which the name starts with “Load”.
  • @SourceGuid: Source Guid, if NULL Source will be retrieved with the value of @Source only.
  • @MasterSourcePattern: The master source to use for this @Source/@SourceGuid
  • @MasterSourceGuid: Master Source Guid, if NULL the connection to the Master Source will be made using only the @MasterSourcePattern. You only need to configure @MasterSourceGuid, if you have multiple master packages in different projects with the same name (e.g. all called “Master.dtsx”) that can run at the same time. In that situation you have to link child- to masterpackages using both @MasterSourcePattern and @MasterSourceGuid.

The easiest way to configure your master- and childpackages is to use spConfigure to set @DefaultMasterSourcePattern so that it matches your masterpackage name.
Then run your masterpackage once. In this way the table [log].[Sources] is already filled with all executed (master- and child)packages, so you do not have to do that yourself.
Then use the examples below to finetune, if necessary.
Examples of use:

--\
---) Set MasterSourcePattern for all sources (use only after SSIS Packages have run for the first time).
--/
EXECUTE [log].[spSetMasterSourcePattern]
  @Source = '%', @MasterSourcePattern = 'Master%'
GO

-- Then undo for the master sources themselves
EXECUTE [log].[spSetMasterSourcePattern]
  @Source = 'Master%', @MasterSourcePattern = NULL
GO

--\
---) Set MasterSourcePattern for one source.
--/
-- Without SourceGuid (use only after SSIS Packages have run for the first time).
EXECUTE [log].[spSetMasterSourcePattern]
  @Source = 'LoadDimCustomer', @MasterSourcePattern = 'DWHMaster'
GO

-- With SourceGuid and MasterSourceGuid (can be used prior to running any packages).
EXECUTE [log].[spSetMasterSourcePattern]
  @Source = 'LoadDimCustomer',
  @SourceGuid = '7480D07D-5099-4B76-9404-17C2AFD0E603', -- PackageID property of SSIS Package.
  @MasterSourcePattern = 'Master',
  @MasterSourceGuid = '0F429F36-784D-4F05-8D5A-9374609A32B9' -- PackageID property of your master SSIS Package.
GO



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Stored procedures [log].[spOnExecutionStart] and [log].[spOnExecutionEnd]

Used internally by the logging solution.


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User defined function [log].[fnLogEntry]

User defined function to select log entries.

This function has the following parameters:

  • @Source: Packagename to select log entries for (including log entries of subpackages). Can be NULL. If NULL then the last execution of any Package will be selected.
  • @LastXExecutions: A number to indicate for how many executions you want to see the log. Defaultvalue is 1.
  • @MaxMessageClass: Filter on MessageClass, for instance use 2 to show only log messages with a MessageClass less than or equal to 2. Defaultvalue is 6.
  • @IncludeRetention0: If 1, also messages with RetentionClass 0 (never delete) will be shown, regardless of their MessageClass.

Example of use:

SELECT * FROM [log].[fnLogEntry] (‘Master’, 1, 4, 1 )
GO



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How to implement logging in own executables

Logging in own executables (for instance C# Console Applications) is fairly easy to set up.
Keep the following in mind:

  • Generate a new guid every time the executable runs, and use it as value for @ExecutionGuid.
  • Assign the executable a persistent SourceGuid, and use it as value for @SourceGuid.
  • Use the executable name as value for @Source. While the executable runs, you can use lower level names (e.g. class and/or method names) for @Source, but still use the executable @SourceGuid, and not a different one.
  • When the executable starts, use the stored procedure spAddLogEntry to add an entry with @event=”ExecutionStart”. This triggers built in facilities of the logging solution.
  • Just before the executable stops, use the stored procedure spAddLogEntry to add an entry with @event=”ExecutionEnd”.
  • When the application is called from within a SSIS Package, use spSetMasterSourcePattern to create a master/child relationship.
  • If you are interested in a C# code example just let me know, and I will dedicate a future blog post to it.

 

Download the logging solution script here.

How about updates?

I intend to update the solution when needed.
If you find bugs or have interesting additions, I would be thankful if you can share those with me so I can improve the logging solution.

(c) 2016 hansmichiels.com – Do not steal the contents – spread the link instead – thank you.