Logging in Multitenant Applications:

 

This is a continuation of the detailed article on Azure Monitoring but with an emphasis on logs.  Azure Monitor and Azure Monitor Logs are different services and Logs are incredibly useful for troubleshooting and notifications.

 

When the cloud monitoring service such as Azure Monitor logs is used to monitor elastic pools and databases for a multitenant application, typically only one account and namespace is needed for the entire integration unlike keyvaults, storage accounts, application instances and databases that proliferate in size and number with the number of tenants. A single geographical region and instance of the Azure Monitor logs is sufficient for the multitenant application solution. 

 

Azure Monitor logs support monitoring thousands of elastic pools and hundreds of thousands of databases.  Azure monitor logs provide a single monitoring solution which can integrate monitoring of different applications and Azure services across multiple Azure subscriptions.

 

A single cloud resource such as an Azure SQL Database can have monitoring and alerting made available via the Portal. It is not convenient to query these logs for large installations or for a unified view across resources and subscriptions. Azure Monitor Logs can collect logs from various resources and their services. The SQL Analytics solution provides several predefined elastic pool and database monitoring and alerting views and queries. It also provides a custom view designer.

 

Platform diagnostics data can be created by simulating a workload on the tenant. Provisioning a batch of tenants prior to the simulation is recommended because it will be close to the real-world scenario.

Also, the Log Analytics Workspace and the Azure SQL Analytics solution must be installed and configured prior to the workload. Azure Monitor Logs is different from Azure Monitor and collects logs and telemetry data in a Log Analytics workspace. The workspace can be created in a dedicated resource group. With the help of the Azure Portal, a Log Analytics workspace and the SQL Analytics solution can be activated. It might take a couple of minutes before the solution is active. The titles or individual databases can then be opened in a drop-down menu.

 

The Portal allows for date range-based filtering, and it shows the pools and databases on the server. Pool level metrics are also available. Monitoring and alerting in the Azure monitor logs are based on queries over the data in the workspace and not specific to a resource. This enables us to               query across databases and subscriptions. Alert rules can also be set up in Azure Monitor Logs. The billing is based on the data volume in the workspace. A free workspace is limited to 500MB/data. After that limit is reached, the data is no longer added to the workspace. This is not the case with the premium tiers.