SQLServer centralized backup monitoring with PowerShell and TSQL (2/2)

From commons.wikipedia.org. Author: włodiIn my previous post  I’ve shown how to collect data and insert it into a database table using PowerShell. Now it’s time to get some information from that data, and I’ve used TSQL for this purpose.

The backup exceptions

Every environment has some backup rules and backup exceptions. For example, you don’t want to check for failures on the model, northwind, adventureworks or distribution databases.

I’ve got the rid of this problem by using the “exception table” created in the previous post. The rules are defined by pattern matching. First we need to define a generic rule for our default backup schedules:

In the previous example, we’ll check that all databases (‘%’) on all instances (again ‘%’)  have been backed up at least every 36 hours, and a backup log have occurred in the last 12 hours. The description is useful to remember why such rule exists.

The “BestBefore” column allows to define the time limit of the rule. For example, if you do some maintenance and you are skipping some schedules, you can safely insert a rule that expires after X days, so you can avoid some alerts while avoiding also to forget to delete the rule.

The previous rule will skip backup reports on SERVER1 until May 12th.

The previous rule will skip all reports on all Northwind databases.

Important: If multiple rules apply to the same database, the rule with a higher time threshold wins.

The queries

The following query lists the databases with the last backup full older than the defined threshold:

And the following will do the same for the transaction logs:

Putting all together

Copy and paste the following to a new Transact-SQL job step in SQLAgent:

Any comment appreciated!

Previous: SQLServer centralized backup monitoring with PowerShell and TSQL (1/2)



SQLServer centralized backup monitoring with PowerShell and TSQL (1/2)

U.S. Air Force: public domain imageChecking database backups has always been one of the main concerns of DBAs. With Oracle is quite easy with a central RMAN catalog, but with other databases doing it with few effort can be a great challenge.

Some years ago I developed a little framework to control all SQLServer databases. This framework was based on Linux (strange but true!), bash, freetds, sqsh and flat configuration files. It’s still doing well its work, but not all SQLServer DBAs can deal with complex bash scripting, so a customer of mines asked me if I was able to rewrite it with a language Microsoft-like.

So I decided to go for a PowerShell script in conjunction with a couple of tables for the configuration and the data, and a simple TSQL script to provide HTML reporting. I have to say, I’m not an expert on PowerShell, but it’s far from being as flexible as other programming languages (damn, comparing to perl, python or php they have in common only the initial ‘P’). However I managed to do something usable.

The principle

This is quite simple: the PowerShell script looks up for the list of instance in a reference table, then it sequentially connect to and retrieves the data:

  • recovery mode
  • status
  • creation time
  • last full backup
  • last log backup

This data is merged into a table on the central repository. Finally, a TSQL script do some reporting.


Custom classes in powershell

One of the big messes with PowerShell is the lack of the definition for custom classes, this is a special mess if we consider that PowerShell is higly object-oriented. To define your own classes to work with, you have to define them in another language (C# in this example):

For better code reading, I’ve put this definition in a separate file (DatabaseBackup.ps1).

The query that retrieves the data…

Actually I use this query to get the information:

I’ve also put this snippet in a separate file queries.ps1 to improve readability.

The tables

The first table (DB_Servers) can be as simple as a single column containing the instances to check. This can be any other kind of source like a corporate CMDB or similar.

The second table will contain the data collected. Off course it can be expanded!

The third table will contain some rules for managing exceptions. Such exceptions can be useful if you have situations like “all databases named northwind should not be checked”. I’ll show some examples in the next post.


The main code

Change this to whatever you want…

This initializes the files explained earlier:

This adds the required snap-in to query sqlserver

The following function will, given the instance, do the following:

  • Get the data in a ResultSet
  • Instantiate an instance of the DatabaseBackup class (the one we defined in the external file) for each row
  • Return an array of DatabaseBackup objects with all the data ready to be processed

This is the real “main” of the script, connecting to the central instance and getting the list of the instances to check:

Finally, for each instance we have to check, we trigger the function that collects the data and we insert the results in the central repository (I’m using a merge to update the existent records).

How to use it

  • Create the tables and insert your instances in the table db_servers.
  • Put the three files (Collect_Backup_Data.ps1,queries.ps1 and DatabaseBackup.ps1) in a directory, modify the instance name and db name in Collect_Backup_Data.ps1
  • Schedule the main script using the SQLAgent  as a Operating system (CmdExec):

  • You can’t use the internal powershell of SQLServer because it’s not full compatible with powershell 2.0.
  • Check that the table db_status is getting populated


  • The script use Windows authentication, assuming you are working with a centralized domain user. If you want to use the SQL authentication (example if you are a multi-tenant managed services provider) you need to store your passwords somewhere…
  • This script is intended to be used with single instances. It should works on clusters but I haven’t tested it.
  • Check the backup chain up to the tape library. Relying on the information contained in the msdb is not a reliable monitoring solution!!

In my next post we’ll see how to generate HTML reports via email and manage exceptions.

Hope you’ll find it useful.

Again PLEASE, if you improve it, kindly send me back a copy or blog it and post the link in the comments!

Next: SQLServer centralized backup monitoring with PowerShell and TSQL (2/2)