Slow MetricsExtensions restart loop by adjusting systemd restart limits

[ngowran]

Currently:

• metrics-extension services use systemd’s default fast restart behavior
• On repeated startup failure, systemd restarts them very quickly and hits the default start limit within a few seconds.
• This creates a tight restart loop and noisy journald logs

Update:

• On failure, the service is retried every 60 seconds instead of every 100 ms
• If it fails more than 5 times within any 10‑minute window, StartLimitBurst is reached and systemd stops restarting it until that window moves on or you intervene (need to discuss implications of this)
• This keeps automatic retries but spreads them out

Note: Putting the three additional systemd service settings in [service] instead of [unit] so they are compatible with all OS we support: https://learn.microsoft.com/en-us/azure/azure-monitor/agents/azure-monitor-agent-supported-operating-systems#linux-operating-systems. Some have older systemd versions >=219

Also using StartLimitInterval over StartLimitIntervalSec for compatibility as per above.

[ngowran]

@ngowran please read the following Contributor License Agreement(CLA). If you agree with the CLA, please reply with the following information.

@microsoft-github-policy-service agree [company="{your company}"]

Options:

• (default - no company specified) I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

@microsoft-github-policy-service agree

• (when company given) I am making Submissions in the course of work for my employer (or my employer has intellectual property rights in my Submissions by contract or applicable law). I have permission from my employer to make Submissions and enter into this Agreement on behalf of my employer. By signing below, the defined term “You” includes me and my employer.

@microsoft-github-policy-service agree company="Microsoft"

Contributor License Agreement

@microsoft-github-policy-service agree company="Microsoft"