Azure SQL Database / Managed Instance monitoring

Solution for near-realtime monitoring on Azure SQL database and Azure SQL Managed instance using the telegraf SQL plugin . A previous version was covered under the blog Near-realtime monitoring for managed instances

VM Setup

Create an Ubuntu VM in a new or an existing resource group with a data disk and mount the attached data disk in the Linux OS. Other Linux distros will work as well, but commands may need to be adjusted accordingly.

The easiest way it to create an Ubuntu VM using the portal, as it will setup everything automatically for you. Just make sure you configure the NSG group to allow access inbound from specific client IPs to destination port 3000 (which is the port used by Grafana UI) on this VM.

Example with Az CLI Create a resource group with the az group create command. Preferably, use the region where the monitored resources are located.

Create the Ubuntu VM with az vm create : Sample CLI command here creates a VM with SSH authentication, as well as with an additional 1TB data disk which will be used to store the monitoring data. Typical customizations to the below command include:

• Specify an existing public key using the --ssh-key-values argument
• Specify an existing VNET and subnet using --vnet-name and --subnet arguments
• Customize the admin username for the VM using --admin-username

az vm create --resource-group <ResourceGroupName> --name <VmName> --image UbuntuLTS --size <Standard_DS2_v2> --generate-ssh-keys --nsg-rule SSH --data-disk-sizes-gb 1024

Connect to the VM and mount the new disk to the VM.. Please keep in mind that the mount point for the data disk by default is /datadrive (as per the above doc). The subsequent scripts in this repo assume a default of /data/influxdb. So either:

• Use /data/influxdb as the mount point for the data disk, OR
• Adjust the INFLUXDB_HOST_DIRECTORY setting mentioned later, to match the mount point used above.

Clone repo

The repo includes grafana dashboards for Azure SQL Database and Managed instances, and setup scripts for influxdb, telegraf and grafana.

cd $HOME
sudo apt-get install git
git clone https://github.com/denzilribeiro/sqldbmonitoring.git

Setup

Setup will install docker.io, will install the telegraf latest release build and configure the firewall to open up port 3000 required for Grafana and pull and start the Grafana container.

cd $HOME/sqldbmonitoring
sudo ./monitoringsetup.sh

If you want to install the latest nightly build with most recent telegraf changes

cd $HOME/sqldbmonitoring 
sudo ./monitoringsetup.sh nightly

Install, Configure and start InfluxDB

Assuming you have mounted a separate data drive as specified in the Setup VM portion , edit the ./runinfluxdb.sh file and modify the INFLUXDB_HOST_DIRECTORY variable to point to the directory where you want the InfluxDB volume to be mounted, if it is something other than the default of /data/influxdb.

cd $HOME/sqldbmonitoring/influxdb
sudo nano runinfluxdb.sh

Pull the docker image and start InfluxDB:

cd $HOME/sqldbmonitoring/influxdb
sudo ./runinfluxdb.sh

Create Logins for each Managed Instance or SQL DB being monitored

Note: Please ENSURE that you replace the sample passwords given below with a truly strong password, before executing the same.

For Managed Instance:

USE master;
CREATE LOGIN telegraf WITH PASSWORD = N'StrongPassword1!', CHECK_POLICY = ON;
GO
GRANT VIEW SERVER STATE TO telegraf;
GO
GRANT VIEW ANY DEFINITION TO telegraf;
GO

For SQL DB create a database scoped user for each database being monitored:

CREATE USER [telegraf] WITH PASSWORD = N'Mystrongpassword1!';
GO
GRANT VIEW DATABASE STATE TO [telegraf];
GO

Edit the telegraf configuration file

Edit the /etc/telegraf/telegraf.conf to add one connection string per each database you want to monitor. Optionally, modify the /etc/telegraf/telegraf.conf with the options specified here

Note: For Azure SQL Database, you would need one connection string per database you are monitoring specifying the right database name and not master. An example snippet for monitoring two databases, each on a different logical SQL server, is shown below:

[[inputs.sqlserver]]
servers = ["Server=server1.database.windows.net;Port=1433;User Id=telegraf;Password=Mystrongpassword1!;database=myazuredb1;app name=telegraf;"
,"Server=server2.database.windows.net;Port=1433;User Id=telegraf;Password=Mystrongpassword1!;database=myazuredb2;app name=telegraf;"]

query_version = 2
azuredb=true

By default all the collectors are enabled. If you copy the sample telegraf.conf the Schedulers and SqlRequests collector are excluded as they are chattier than other collectors. You can control what collectors to exclude by including them in the excluded array in the conf file

exclude_query = [ 'Schedulers' , 'SqlRequests']

If the influx DB docker container is on the same VM then the section below doesn’t have to change, if it is on another machine or non-default port, the url would have to be updated accordingly.

urls = ["[http://127.0.0.1:8086](http://127.0.0.1:8086/)"]
database = "telegraf"

Note:

• Port for Azure SQL Managed Instance with public endpoint is 3342
• If influxDB is hosted on a different VM have to modify the url for outputs.influxdb
• Default polling interval is 10 seconds, if you want to change that have to add /change the Agent Interval value.

Start the telegraf service

Use the commands below to start telegraf and check its status:

sudo systemctl start telegraf
sudo systemctl status telegraf

To Troubleshoot any failures you can look at the log entries using the command:

sudo journalctl -u telegraf --no-pager

Create Telegraf database and retention policy

We want to set a retention policy in influxdb based on how long data needs to be kept. To do so, you can use the create retention policy command within Influx (example below):

sudo docker exec -it influxdb influx
use telegraf;
show retention policies;
create retention policy retain30days on telegraf duration 30d replication 1 default;
quit

Configure Grafana data source and dashboards

The Dashboards are located here:

• Azure SQL Database Dashboards
• Azure SQL Managed Instance Dashboards

But first, we need to create the data source for InfluxDB in Grafana:

• Browse to your Grafana instance - http://[GRAFANA_IP_ADDRESS_OR_SERVERNAME]:3000

• First time you login into Grafana, login and password are set to: admin. Also take a look at the Getting Started Grafana documentation.

• Add a data source for InfluxDB. Detailed instructions are at in the grafana data source docs

  • Type: InfluxDB
  • Name: InfluxDB (this is also the default)
  • URL: http://[INFLUXDB_HOSTNAME_OR_IP_ADDRESS]:8086. (The default of http://localhost:8086 works if Grafana and InfluxDB are on the same machine; make sure to explicitly enter this URL in the field. )
  • Database: telegraf
  • Click "Save & Test". You should see the message "Data source is working".

• Then, we can download Grafana dashboard JSON definitions from the repo Azure SQL DB dashboards folder or Azure SQL Managed Instance Dashboards for all the dashboards, and then import them into Grafana.

** Note:** If you changed the name of the datasource above from the default value of InfluxDB, then you will need to edit the JSON for the dashboards and change "datasource": "InfluxDB" to "datasource": "YOURDATASOURCENAME", where YOURDATASOURCENAME is a placeholder for the actual datasource name.

Dashboard samples

As mentioned above, we provide some sample dashboards, which can be customized by you as needed:

• AzureSQLDBEstate.json: This is for Azure SQL Databases and not for Managed Instances. This gives you a row per logical SQL Server, and a top level view of all the servers and databases, from which you can then drill-through to an individual database.
• AzureSQLDBPerformance.json: This is a database level view of performance, going from high level metrics, to wait stats, to performance counters, and typically serves as the primary performance dashboard.
• AzureSQLDBStorage.json: This dashboard is primarily based on virtual file stats DMV, and gives you a view of storage latency for the respective databases.