This is a T-SQL Tuesday that not only makes me smile, but makes my boss happy. In fact, I’m sure that quite a few people at Redgate Software, my employer, are thrilled with this topic since we have a product that helps you here: SQL Monitor.

T-SQL Tuesday #66 has the theme of monitoring, hosted by Catherine Wilhelmsen. Anything having to do with monitoring is fair game. Custom scripts, home grown applications, even third party software.

If you’re a #SQLNewBlogger, this is a great chance to keep going with a new post. If you can’t write now, come back and publish something later. If you post something on May 12, 2015, you’ll get included in Catherine’s roundup. However if you can’t make it, you’re still a T-SQL Tuesday writer.

Either way, follow #tsql2sday and learn a few things.

Self Monitoring

My post is going to be more of a philosophical one, with a little code.

Most of the time I’ve worked with SQL Server, I’d had some responsibility for a production instance. Even when I was writing code and building software, I’d still find myself as the backup, if not the primary, accidental DBA. I learned early on that I needed to have some way to track what was happening on an instance.

One of the ways in which I did this was by ensuring each instance could monitor itself. I’d found far too many times that having a process connect remotely to the instance and gather data was a way to lose data. Too often something would get missed. The exact time that a process connected was the time things didn’t work.

As a result, I decided to keep some monitoring on the local instance. Even though I usually had a central server roll up information, if that instance dropped off the network (or my monitoring server died), I’d still know what was going on. This was especially important when I worked in the financial industry or was bound by ISO 9000 standards.

Note: These days I don’t bother to manage monitoring software of my own on an instance. I use SQL Monitor because I work for Red Gate, but no matter who my employer might be, I’d buy software because it’s worth the cost. I don’t have the time to worry about maintaining my own software for most monitoring tasks.

DBAAdmin

I had a setup routine that I used to use on every instance. It did a few things, the first of which was create a DBAAdmin database. This was the place I could put anything I needed to monitor my instance. I tried to keep all the code the same between instances, and tried to write idempotent code so that re-running the install wouldn’t cause issues.

Once I had the database, I’d add tables and procedures for various purposes. For example, one of the things that needed to be tracked each day was the backups for the databases. So I created a table called DBBackups.

CREATE TABLE DBBackups
( BackupID INT IDENTITY(1,1)
, Backupdate DATETIME
, DatabaseName VARCHAR(2000)
, BackupType CHAR(1)
, Filename VARCHAR(2000)
, sizeGB NUMERIC(15,2)
)
;

This table had a corresponding procedure that was designed to scan the filesystem and report back on the latest backups written to the file system. The details of each file are recorded here.

Why? If there’s a problem with monitoring, the local machine still has the information about backups. What’s more, I can usually get more details here than I’m capturing in a monitoring system that’s looking at the last backup date or just getting full backups. If msdb history is wiped, I have a second copy here.

However I also need to remove data over time, so this solution usually has three parts.

• Table for data storage
• Procedure(s) for gathering data
• Procedure and job to remove data older than xx days

That’s simple, but it’s a decent amount of work. However I only use this for certain areas. I used to really care about backups, but SQL Monitor captures that for me. However I might care about sp_configure settings. While SQL Monitor can alert me if there are changes, how do I know what changed? I’ve used a process like this to keep the last week’s worth of sp_configure information, captured every day to let me look back.

As I noted above, I wouldn’t rebuild a monitoring solution for overall checking of a database, but I might capture specific information using this process, with the table and procedures tailored to the specific information I care about.