Enhance the buffer cache hit ratio calculations for performance metrics

[anil-elastic]

Proposed commit message

Enhance the buffer cache hit ratio calculations by adding buffer cache hit ratio base and modifying the calculation for performance metrics.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Disruptive User Impact

Author's Checklist

• [ ]

How to test this PR locally

Below files changes used to test it:
File : mssql/docker-compose.yml

version: '2.3'
services:
  microsoft_sqlserver:
    image: mcr.microsoft.com/mssql/server:2019-latest
    user: root
    environment:
      - ACCEPT_EULA=Y
      - SA_PASSWORD=Password123
    ports:
      - "1433:1433"

file: mssql.yml

- module: mssql
  metricsets:
    - "transaction_log"
    - "performance"
  hosts: ["sqlserver://0.0.0.0:1433"]
  username: sa
  password: Password123
  period: 10s

Related issues

• Closes [metricbeat mssql] buffer cache hit ratio calculations for performance metrics #36876

Use cases

Screenshots

Logs

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @anil-elastic? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v8./d.0 is the label to automatically backport to the 8./d branch. /d is the digit

[anil-elastic]

@elastic/obs-infraobs-integrations I am not able to replicate the error locally because when I run MODULE="mssql" mage goIntegTest I always get below error:

performance_integration_test.go:27: failed to start service 'mssql': ps: failed to get container list: failed to get list of service names: exit status 1

[shmsr]

Looks good. Let's wait for CI to go green.