Create ADR detailing our choice of Grafana for monitoring

- Focuses on Acceptance criteria and overall ability of tool

Author: TheOneFromNorway

adr/00013-grafana-for-monitoring-and-alerting.md

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+# 13. Amazon Managed Grafana for Monitoring and Alerting
+
+Date: 2025-07-01
+
+## Status
+
+Accepted
+
+## Context
+
+Currently, monitoring is done via CloudWatch and alerts are based on Sentry. We want to improve the monitoring and
+alerting capabilities of the Mavis application by integrating a more robust and unified solution.
+
+### Acceptance Criteria
+
+1. Fully cloud native solution that integrates with AWS services.
+2. Monitoring does not require access to the AWS console.
+3. Can be fully managed and automated using terraform.
+4. Aligns with TechRadar's accepted technologies.
+5. Authentication aligns with existing Identity and Access Management (IAM) setup.
+6. Allows Alerts to be configured and managed within the same platform.
+
+## Considered Options
+
+### Option 1 : AWS CloudWatch Dashboards and Alarms
+
+This option involves expanding our use of the native AWS CloudWatch service for all monitoring and alerting, creating
+more sophisticated dashboards and migrating all alerts to CloudWatch Alarms.
+
+- **Pros**:
+  - Deeply integrated with all AWS services.
+  - Fully manageable via Terraform.
+  - Provides both dashboarding and alerting in a single service.
+- **Cons**:
+  - Less flexible and powerful dashboarding capabilities.
+  - User experience requires returning to the AWS console.
+
+### Option 2 : Splunk
+
+This option would involve leveraging our existing Splunk integration to handle not just log aggregation but also
+metric-based monitoring and alerting.
+
+- **Pros**:
+  - Powerful alerting features based on complex log queries.
+  - Can view dashboards without accessing the AWS console.
+- **Cons**:
+  - Primarily a log analysis tool, not ideal for metric-based monitoring.
+  - Integrating it AWS is more difficult as it is an external service.
+  - Restricting NHS-wide access to dashboards and alerts would require additional configuration.
+
+### Option 3 : Amazon OpenSearch Service
+
+This involves using the managed OpenSearch service, which includes OpenSearch Dashboards and an integrated alerting
+plugin.
+
+- **Pros**:
+  - Fully managed AWS service.
+  - Provides powerful log analytics, visualization, and alerting.
+  - Can view dashboards without accessing the AWS console.
+- **Cons**:
+  - Core strength is in log data, not metrics.
+  - Metric-based alerting setup is more complex than specialized tools.
+  - Potentially overkill for our primary requirements.
+
+### Option 4 : Amazon Managed Grafana
+
+A fully managed service for the open-source Grafana platform, which is a popular tool for analytics, interactive
+visualization, and alerting.
+
+- **Pros**:
+  - Purpose-built for unified dashboards and alerting.
+  - Best-in-class visualization capabilities.
+  - Integrates seamlessly with CloudWatch and AWS IAM Identity Center.
+  - Fully manageable via Terraform.
+  - Can view dashboards without accessing the AWS console.
+- **Cons**:
+  - Introduces a new service to the architecture.
+
+## Decision
+
+We will adopt **Amazon Managed Grafana** as our primary monitoring and alerting solution.
+
+It is the only option that excels at meeting all our acceptance criteria, especially the need for a unified platform for
+both visualization and alerting. It provides best-in-class dashboard features while also integrating an alerting system.
+The service also integrates well with multiple types of data (logs, streams, metrics, etc.)
+This allows us to consolidate our tooling and deprecate the use of Sentry for alerts, creating a more streamlined
+operational workflow. Its native integration with AWS for data sources (CloudWatch) and authentication (IAM Identity
+Center) makes it a natural fit, and as an AWS Service it is tech radar accepted.
+
+## Consequences
+
+- We will provision a new Amazon Managed Grafana workspace using Terraform.
+- User access will be managed via AWS IAM Identity Center, granting authorized personnel access to dashboards and alert
+  configurations without needing to log into the AWS console.
+- CloudWatch will be configured as the primary data source within Grafana.
+- An initial set of dashboards for key application and infrastructure metrics (e.g., CPU/Memory utilization, database
+  connections, latency) will be created.
+- All future alerting will be configured and managed within Grafana, deprecating our reliance on Sentry for this
+  purpose.