ABC company has multiple data pipeline setup using Azure Data factory. The data team is trying to use Azure monitor for keeping the pipeline run data. The following are the main requirements. Keep run data for at least 60 days.
Write complex queries on metrics published by the data factory.
Monitor Multiple data pipelines in a single workspace.
Which of the options will be the best target for Azure Monitor in this scenario?

Answer options:

A.Storage Account
B.Azure Event Hub
C.Azure Event Grid
D.Log analytics

Correct Answer: D 
The first requirement is storing the data for 60 days. By default, the data pipeline will be stored by Azure Data Factory for almost 45 days. But for storing data for more than 45 days, an Azure monitor should be used. The next requirement is to have the ability to run complex queries on this data which is stored. You can think of running some complex queries and creating some alerts based on those queries. This is a feature available with the Log Analytics workspace. To confirm our answer, we can look at the third feature, which says there should be a single workspace that can be used for all the data pipelines. Creating a single workspace in Log Analytics and collecting data from multiple inputs can be done easily.
Option A incorrect: Storage account does not give you complex query and single workspace options.
Option B is incorrect: Even though the event hub can be used as a target to Azure Monitor, its main purpose is to process streaming data. The feature of querying and workspace is not available here.
Option C is incorrect: Event grid is generally not used as a target for Azure Monitor and is used mainly to build applications with event-based architectures.
Option D is correct: It has query ability, and the log analytics workspace can act as a single target for metrics from different pipelines.
Reference: 
To know more about Monitoring Data Factory pipelines, please refer to the doc below: 

https://docs.microsoft.com/en-us/azure/data-factory/monitor-using-azure-monitor