Ees 5686 add public api performance metric alerts

[duncan-at-hiveit]

This PR adds in various alerts related to performance to resources of the Public API.

This introduces the use of dynamic threshold alerts, which use machine learning to determine normal usage patterns for the resources they monitor and determine a dynamic threshold against which to test the performance of the metric they're tracking.

Alerts included in this PR are:

• Response / end-to-end latency times for:
  • Application Gateway
  • Container Apps
  • File Services
  • Storage Accounts
• Longest query and longest transaction for PostgreSQL Flexible Server

[ntsim]

This can be formatted into a multi-line import i.e.

import {
  EvaluationFrequency,
  ...
} from 'types.bicep'

Note that the built-in Bicep formatter would normally do this automatically.

You can format directly from VS Code by running Format Document (using the command palette). It should prompt you to configure a formatter for Bicep, which I think it does automatically, but I you can also manually configure it in your settings.json.

Would suggest we create a new ticket to add a pre-commit hook to run the Bicep formatter (like how we run Prettier) and then format any other Bicep files so we have a good formatting baseline.

[duncan-at-hiveit]

Sounds good - I've created the following ticket ta: https://dfedigital.atlassian.net/browse/EES-5748

[duncan-at-hiveit]

(and formatted the file using CS Code in the meantime)

[ntsim]

Should these have descriptions?

[duncan-at-hiveit]

Indeed they should! I've added some now - quite descriptive ones as I feel that these various parameters are a little mysterious unless you know alerts inside and out.

[ntsim]

flexibleServers for the directory maybe isn't the best name as it doesn't convey that these alerts are for the Postgres database.

Perhaps postgreSql or postgres would be better?

Or, if it's possible to abstract these alerts for any database type, maybe db could work? (probably needs resourceType to be configurable though)

[duncan-at-hiveit]

It was mostly just to stick with the folder name convention that matched the Azure type of the resources that the alerts were for (in this case Microsoft.DBforPostgreSQL/flexibleServers). For instance, sites rather than functionApps or appServices as an example. I've got no problem changing it though, and so have done to postgreSqlFlexibleServers. At some point, the postgresqlDatabase.bicep file could do with renaming to postgreSqlFlexibleServer.bicep too.

I think that these alerts will be specific to PostgreSQL FS btw rather than generic to all dbs.