Data Collection Rules (DCRs) in Azure Monitor are configuration objects that define how data should be collected, transformed, and sent to destinations within the Azure monitoring ecosystem. They serve as the central mechanism for controlling data ingestion across your Azure environment.
DCRs spec…Data Collection Rules (DCRs) in Azure Monitor are configuration objects that define how data should be collected, transformed, and sent to destinations within the Azure monitoring ecosystem. They serve as the central mechanism for controlling data ingestion across your Azure environment.
DCRs specify three primary components: data sources, transformations, and destinations. Data sources determine what information to gather, including performance counters, Windows Event Logs, Syslog data, custom logs, and IIS logs. Transformations allow you to filter, modify, or enrich data using Kusto Query Language (KQL) before it reaches its destination. Destinations define where the collected data should be sent, such as Log Analytics workspaces, Azure Monitor Metrics, or Azure Event Hubs.
For security engineers working with Microsoft Defender for Cloud and Microsoft Sentinel, DCRs play a crucial role in security monitoring. When configuring data collection for Sentinel, DCRs enable granular control over which security events are ingested, helping optimize costs while maintaining comprehensive visibility. You can filter out noise and focus on high-priority security telemetry.
DCRs support data collection through the Azure Monitor Agent (AMA), which has replaced the legacy Log Analytics agent. This modern approach provides better performance, centralized configuration, and multi-homing capabilities where a single agent can send data to multiple workspaces.
Key benefits include reduced storage costs through pre-ingestion filtering, improved data quality via transformations, and simplified management through a single configuration point. DCRs can be associated with multiple resources using Data Collection Rule Associations (DCRAs), making it efficient to apply consistent collection policies across your infrastructure.
When implementing security solutions, properly configured DCRs ensure that Defender for Cloud and Sentinel receive the necessary telemetry for threat detection, compliance monitoring, and incident response while maintaining cost efficiency and data governance requirements.
Data Collection Rules (DCRs) in Azure Monitor
Why Data Collection Rules Are Important
Data Collection Rules (DCRs) are a critical component of Azure Monitor that control how data is collected, transformed, and routed to destinations. For security professionals, understanding DCRs is essential because they determine what telemetry data is captured for threat detection, compliance monitoring, and incident response. Properly configured DCRs ensure you collect the right security data while optimizing costs and performance.
What Are Data Collection Rules?
Data Collection Rules are configuration resources in Azure that define: - What data to collect (performance counters, Windows events, Syslog, custom logs) - How to transform the data (filtering, parsing, enriching) - Where to send the data (Log Analytics workspaces, Azure Monitor Metrics, Event Hubs)
DCRs replace the legacy data collection methods that were configured within Log Analytics workspace settings, providing a more flexible and scalable approach.
How Data Collection Rules Work
1. Create a DCR: Define the data sources, transformations, and destinations in Azure Portal, CLI, or ARM templates
2. Associate with Resources: Link the DCR to target resources using Data Collection Rule Associations (DCRAs). A single DCR can be associated with multiple VMs or resources
3. Deploy Azure Monitor Agent (AMA): The Azure Monitor Agent uses DCRs to understand what data to collect from the host
4. Data Pipeline: Data flows from source through optional transformations using KQL queries, then routes to specified destinations
Key Components of DCRs
- Data Sources: Performance counters, Windows Event Logs, Syslog, IIS logs, custom text logs - Streams: Define the schema and format of incoming data - Destinations: Log Analytics workspaces, Azure Monitor Metrics, or Azure Event Hubs - Transformations: KQL-based queries that filter, aggregate, or modify data before ingestion
DCRs and Microsoft Defender for Cloud
When enabling Defender for Cloud plans, DCRs are automatically created to collect security-relevant data. The Defender for Servers plan uses DCRs to collect security events and vulnerability data from protected machines.
DCRs and Microsoft Sentinel
For Sentinel deployments, DCRs enable collection of security logs from various sources. You can use transformations to filter out noise and reduce data ingestion costs while maintaining security visibility.
Exam Tips: Answering Questions on Data Collection Rules
Understand the relationship between components: - Azure Monitor Agent requires DCRs to function - DCRAs connect DCRs to specific resources - One DCR can serve multiple machines; one machine can have multiple DCRs
Know the differences from legacy methods: - DCRs replace workspace-based configuration for data collection - The Log Analytics agent (MMA) uses workspace settings, while AMA uses DCRs
Remember transformation capabilities: - Transformations use KQL syntax - They can filter rows, drop columns, or parse data - Transformations help reduce costs by filtering before ingestion
Focus on security scenarios: - Questions may ask about collecting specific Windows Security Events - Understand how to scope DCRs to collect only relevant security data - Know that Defender for Cloud auto-provisions DCRs when plans are enabled
Common exam scenarios: - Choosing between workspace settings and DCRs for new deployments (answer: DCRs with AMA) - Configuring collection of specific event IDs for security monitoring - Reducing data ingestion costs through DCR transformations - Troubleshooting missing data by checking DCRA associations