Metrics and logs are key telemetry types that are widely used to monitor resources in Azure. Metrics provide numerical values representing the state of the resource across a series of intervals. The logs, on the other hand, provide information on all the operations and events happening on that resource.
For data engineers preparing for the DP-203 Data Engineering on Microsoft Azure exam, understanding and interpreting Azure Monitor metrics and logs is crucial.
Understanding Azure Monitor Metrics
Azure Monitor Metrics allow you to understand the behavior of your application and make real-time decisions based on the collected numerical data.
A metric in Azure Monitor is a series of numeric values, or a time-serialized measurement of some aspect of a system, taken at regular intervals. This could be anything from CPU usage, memory usage, thread counts and various other performance indicators. Metrics are lightweight and capable of supporting near real-time scenarios.
To retrieve Azure Monitor metrics, Azure Monitor REST API, Azure SDK or CLI can be used. An example would be using the “az monitor metrics list” command that allows you to list metrics for a resource.
az monitor metrics list --resource --metric --interval --aggregation
Here, the `–resource` specifies the name or id of the Azure resource, `–metric` specifies the name of the metric, `–interval` specifies the time span of the metrics data, and `–aggregation` specifies the metric aggregation type.
Understanding Azure Monitor Logs
Azure Monitor Logs are event and trace logs that offer rich, frequent data about the operation of a system. They contain different kinds of data organized into records with different properties for each type. Log data can be split into two categories: platform logs, which pertain to the operation of a platform as a whole, and resource logs, which pertain to individual resources.
Azure Monitor Logs are based on Azure Data Explorer and its highly robust Kusto Query Language (KQL). To analyze your log data, you would use KQL.
Here is an example of how to retrieve the last 30 days of Azure Diagnostic Logs for a specific storage account using KQL:
AzureDiagnostics
| where Resource == "myStorageAccount"
| where TimeGenerated > ago(30d)
This example demonstrates a basic query where `AzureDiagnostics` specifies the data source, `where Resource == “myStorageAccount”` filters the data based on the resource, and `where TimeGenerated > ago(30d)` limits the timeframe to the last 30 days.
Interacting with Metrics and Logs
Azure Monitor interacts with metrics and logs slightly differently. Metrics are lightweight and suitable for near real-time telemetry, providing numerical values that describe some aspect of your system at a particular point. Logs are useful for storing much more detailed information and for inspecting past states.
| Metric | Log |
|---|---|
| Numerical data | Event or trace data |
| Measured at regular intervals | Can occur at any time |
| Stored in a time-series database | Stored in a Log Analytics workspace |
| Lightweight, suitable for near real-time scenarios | Richest detailed data |
Azure Monitor Metrics and Logs both provide valuable insights, but due to their different nature, they are used for different purposes. Metrics provide values that describe the system at a point in time and allow tracking trends, spotting anomalies, and provisioning resources. Logs provide rich details about operations and events that are used to observe their behavior, diagnose issues, and drive automation.
Conclusion
Comprehending Azure Monitor metrics and logs is a significant step towards mastering the DP-203 Data Engineering on Microsoft Azure exam. They are powerful tools delivering critical insights into the state and performance of your Azure resources. By properly utilizing these insights, data engineers can ensure their Azure applications and services are performant, resilient, and secure.
Practice Test
True/False: Azure Monitor only supports metrics and logs from Azure services.
- True
- False
Answer: False.
Explanation: Azure Monitor can collect metrics and logs not just from Azure services but also from your on-premise environment and other cloud systems.
Which of the following can you monitor with Azure Monitor?
- a) Availability
- b) Performance
- c) Security
- d) All of the above
Answer: d) All of the above.
Explanation: Azure Monitor can collect and analyze data to monitor the availability, performance, and security of your applications and services.
True/False: Azure Monitor metrics are collected in real time and are automatically retained for 93 days.
- True
- False
Answer: True.
Explanation: Azure metrics are collected in real-time, and the default retention period is 93 days, allowing you to perform trend analysis over a three-month period.
Which of the following statements is true about Azure Monitor Logs?
- a) They provide insights into system performance
- b) They can analyze trends
- c) They perform complex analysis across data types
- d) All of the above
Answer: d) All of the above.
Explanation: Azure Monitor Logs can provide insights into system performance, analyze trends, and also conduct complex analysis across multiple sources of data.
True/False: The metrics collected by Azure Monitor are granular and can go down to the minute level.
- True
- False
Answer: True.
Explanation: Azure Monitor provides granular, minute-level metrics for more precise monitoring and alerting based on resource performance.
What is the data type of Azure Monitor Metrics?
- a) Structured
- b) Unstructured
- c) Semi-structured
- d) None of the above
Answer: a) Structured
Explanation: The Azure Monitor Metrics use a structured data type that is lightweight and provides numerical data.
Which of the following can be monitored through Azure Monitor Logs?
- a) Applications
- b) Networks
- c) Azure resources
- d) Custom sources
- e) All of the above
Answer: e) All of the above.
Explanation: Azure Monitor Logs can be applied to applications, networks, Azure resources, and even custom sources for comprehensive monitoring.
True/False: Azure Monitor Metrics and Logs do not support data export.
- True
- False
Answer: False.
Explanation: Azure Monitor supports exporting data to storage accounts, event hubs, or Azure Monitor logs for long-term retention or integration with external systems.
Multiple Select: Which of the following are visualization tools used with Azure Monitor metrics and logs?
- a) Power BI
- b) Azure portal graphs
- c) Azure Dashboards
- d) Google Data Studio
Answer: a) Power BI, b) Azure portal graphs, c) Azure Dashboards
Explanation: Azure Monitor uses Power BI, Azure portal graphs, and Azure Dashboards to visualize metrics and logs. Google Data Studio is not supported.
True/False: You cannot create alert rules based on Azure Monitor Metrics.
- True
- False
Answer: False.
Explanation: Azure Monitor allows you to create alert rules based on measurements of metrics over time.
Interview Questions
What is Azure Monitor used for?
Azure Monitor maximizes the availability and performance of applications by delivering a comprehensive solution for collecting, analyzing, and acting on telemetry from cloud and on-premises environments.
What are Azure Monitor Metrics?
Metrics in Azure Monitor are numerical values that describe some aspect of a system at a particular point in time. They are lightweight and capable of supporting near real-time scenarios.
What are Azure Monitor Logs?
Logs in Azure Monitor contain different kinds of data organized into records with different sets of properties for each type. Telemetry such as events and traces are stored as logs in addition to performance data so that it can all be combined for analysis.
How do you use Azure Monitor metrics to identify performance bottlenecks?
Azure Monitor metrics can be used to identify performance bottlenecks by tracking the latency, throughput, and other performance-related measures of your applications and finding out which ones are not matching up with your expected performance goals.
How can Azure Monitor logs help in troubleshooting issues?
Azure Monitor logs can contain detailed records of operations executed by the resources, making them extremely useful for troubleshooting. By analyzing these logs, you can identify patterns, trends, and anomalies that could indicate a problem.
What is log query in Azure Monitor?
Log query is a powerful tool in Azure Monitor used for retrieving, consolidating, and analyzing collected monitoring data. It gives you the ability to execute complex operations to analyze data, which cannot be achieved using metrics alone.
How do you create alerts based on metrics in Azure Monitor?
Alerts Using Metrics can be created in Azure Monitor by clicking on the Alerts Menu and selecting “New Alert Rule”. You then select a target resource, condition based on the specific metrics, and an action group.
Can Azure Monitor be used with on-premises infrastructure?
Yes, Azure Monitor can collect data from a variety of sources. This includes on-premises environment as well as any application, regardless of whether the application is hosted within Azure, another cloud service, or on-premises.
Are metrics and logs stored indefinitely in Azure Monitor?
No, they’re not stored indefinitely. Azure Monitor retains metric data for 93 days and log data can be retained from 31 to 730 days depending on the specific requirements of the user.
How does Azure Diagnostic Logs differ from Azure Monitor Logs?
Azure Diagnostic Logs contain all logged information from a resource, whereas Azure Monitor Logs can be described as a query and analysis service over log data. Azure Monitor Logs allow for complex analysis across logs from various sources.
Can the data collected by Azure Monitor be sent to other tools for more analysis?
Yes, the data collected by Azure Monitor can be exported to event hubs for streaming to third-party SIEM tools or to a storage account for archival purposes or additional analysis.
What is the role of Azure Monitor in Azure DevOps?
Azure Monitor plays a crucial role in Azure DevOps in the areas of monitoring, diagnosing, and scaling applications in development and production stages. It provides real-time insights into the applications’ performance, helping developers troubleshoot faster and enhance their operations.
Can Azure Monitor give real-time alerts?
Yes, Azure Monitor can provide real-time alerts. When an alert triggers, Azure Monitor can send a notification or can call a webhook to trigger some automated processes.
What are Application Insights?
Application Insights is an extensible Application Performance Management service for developers and DevOps professionals which is a part of Azure Monitor. It is used to monitor live applications, helping to detect and diagnose performance issues and understand what users do with your app.
Can you use Azure Monitor for proactive identification of issues?
Yes, Azure Monitor can be configured to provide proactive alerts and notifications based on identified patterns, thresholds, or anomalies in your data.
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