Azure ETL solutions can help reduce data processing time by up to 90% compared to on-premises solutions.
This is because Azure ETL solutions can handle large volumes of data in parallel, making them ideal for big data processing.
Azure Data Factory, a key component of Azure ETL, allows you to create and manage data pipelines with ease, reducing the time and effort required to integrate data from different sources.
With Azure ETL, you can also automate data transformation and loading processes, freeing up your team to focus on higher-value tasks.
What Is Azure ETL?
Azure ETL is a process that involves extracting data from a source, transforming it into a desired format, and loading it into a target system. This process is a crucial part of data integration and is used to move and transform data between supported data stores.
Azure Data Factory (ADF) is primarily used as an ETL tool, allowing users to create, schedule, and manage data-driven workflows. These workflows, called pipelines, are designed to move and transform data between supported data stores.
The ETL process can be used for various tasks, such as data migration, data warehousing, and data integration. ADF can also integrate with other compute services in the Microsoft Azure ecosystem for data transformation tasks.
Data transformation tasks can be complex, but ADF makes it easier by providing a user-friendly interface and a wide range of tools and services. This versatility makes ADF a formidable solution for data movement, transformation, and orchestration.
Setting Up and Configuring
To set up and configure Azure ETL, you'll need to configure access to an Azure storage account, which both Azure Databricks and Synapse require for temporary data storage. You can do this by using the account key and secret for the storage account and setting forwardSparkAzureStorageCredentials to true.
Azure Synapse does not support using SAS for storage account access, so you'll need to use one of the following methods to configure access: using the account key and secret, using Azure Data Lake Storage Gen2 with OAuth 2.0 authentication, or configuring a Managed Service Identity for your Synapse instance.
Here are the three methods to configure access to Azure storage:
- Use the account key and secret for the storage account and set forwardSparkAzureStorageCredentials to true.
- Use Azure Data Lake Storage Gen2 with OAuth 2.0 authentication and set enableServicePrincipalAuth to true.
- Configure your Azure Synapse instance to have a Managed Service Identity and set useAzureMSI to true.
Additionally, if you configure a firewall on Azure Synapse, you must configure network settings to allow Azure Databricks to reach Azure Synapse. This involves configuring IP firewall rules on Azure Synapse to allow connections from your subnets to your Synapse account.
Setting Up
To set up your Azure Synapse Analytics connection, you'll first need to configure access to Azure storage. This is necessary for both Azure Databricks and Synapse to use for temporary data storage.
Both services need privileged access to an Azure storage account, and you can achieve this by using the account key and secret for the storage account and setting forwardSparkAzureStorageCredentials to true.
Alternatively, you can use Azure Data Lake Storage Gen2 with OAuth 2.0 authentication and set enableServicePrincipalAuth to true. This is useful if you already have a service principal set up.
You can also configure your Azure Synapse instance to have a Managed Service Identity and set useAzureMSI to true, which is another option for accessing Azure storage.
The table below summarizes the options for configuring access to Azure storage:
To authenticate to Azure Synapse Analytics, you can use a service principal with access to the underlying storage account. This requires setting the enableServicePrincipalAuth option to true in the connection configuration.
Streamlining IT Needs
Streamlining IT needs is crucial for any organization. Azure might not be the best fit for everyone, but Shipyard offers a comparable and robust platform for building an ELT pipeline.
Shipyard is a data orchestration platform that helps data practitioners quickly launch, monitor, and share highly resilient data workflows. Its emphasis on rapid launching, monitoring, and integrations makes it a worthy contender.
Rapid launching and effortless scaling are key features of Shipyard. You can also rely on built-in security and a plethora of integrations.
Shipyard's data automation tools and integrations work seamlessly with your existing data stack or modernize your legacy systems. This makes it an excellent choice for organizations looking to upgrade their IT infrastructure.
Signing up for a demo of the Shipyard app is a great way to experience its capabilities firsthand. The free Developer plan requires no credit card, making it easy to get started.
Data Storage and Management
Storing transformed data is a crucial part of the Azure ETL pipeline, and it's done by writing the DataFrames to Azure Data Lake Storage Gen2 in CSV format. This ensures that each DataFrame is written to a single CSV file.
The code specifies options such as overwriting existing data and treating the first row as headers, which helps maintain data consistency. Proper access controls and permissions are also set up for the Azure Data Lake Storage Gen2 account to restrict unauthorized access.
To ensure smooth data storage and management, it's good practice to handle errors and exceptions during the write operation. This can be achieved by adding try-except blocks to the code.
Storing Transformed
Storing Transformed Data is a crucial step in the data pipeline, and it's essential to get it right. It involves writing the transformed DataFrames to a storage location, such as Azure Data Lake Storage Gen2, in a format like CSV.
This code ensures each DataFrame is written to a single CSV file, with options for overwriting existing data and treating the first row as headers. The data is organized into separate directories within the storage account for better organization and management.
It's good practice to handle errors and exceptions during the write operation, as mentioned in the best practices. This helps prevent data loss and ensures the pipeline runs smoothly.
Depending on the size of the data, consider partitioning it into multiple files for better performance. This can significantly speed up the write operation and make the data more manageable.
Proper access controls and permissions are also crucial for the Azure Data Lake Storage Gen2 account. This restricts unauthorized access and ensures only authorized personnel can modify or view the data.
Here are some key considerations for storing transformed data:
- Handle errors and exceptions during the write operation.
- Partition the data into multiple files for better performance.
- Ensure proper access controls and permissions are set up for the storage account.
Analytics
Azure Synapse Analytics is a great choice for storing prepared results. It's an analytical database store optimized for analytic workloads, and it scales based on partitioned tables.
To create a table in Azure Synapse Analytics, you can use the Synapse Studio. Select the Lake database, name it, and then create an external table by selecting the linked service and the file with the transformed data.
Azure Analysis Services provides analytical data for business reports and client applications like Power BI. It works with Excel, SQL Server Reporting Services reports, and other data visualization tools.
Scaling analysis cubes in Azure Analysis Services is done by changing tiers for each individual cube. This can be done to optimize performance and scalability.
Azure Data Factory provides a data movement activity like Copy Data, Data Flow, and Data Lake Storage. This allows for parallelism and partitioning to gain optimal data movement performance and scalability.
Designing scalable ETL processes in Azure Data Factory involves considering several key factors, including data movement considerations, data transformation strategies, and workflow orchestration techniques.
To implement scalable ETL processes in Azure Data Factory, start by setting up an instance of a Data Factory and defining linked services. Then, design the data pipelines in a visual way, configuring data movement and transformation activities.
Best practices for scaling ETL processes with Azure Data Factory include designing principles for scalability, performance tuning techniques, error handling and fault tolerance, and security considerations.
Data Transformation and Load
Data transformation is a crucial step in the ETL process, and HDInsight supports various tools for this task, including Hive, Pig, and Spark SQL.
These tools enable you to clean, combine, and prepare your data for specific usage patterns.
After data transformation, it's time to load the data into other products, and HDInsight supports Sqoop and Flume for this purpose.
Sqoop uses MapReduce to import and export data, providing parallel operation and fault tolerance.
To get started with data transformation and load, consider using Azure Data Factory (ADF), which offers a cloud-based data integration service that enables users to create, schedule, and orchestrate data workflows at scale.
ADF supports a variety of data sources and destinations, allowing for seamless data movement across on-premises and cloud environments.
Here's a list of some popular Azure services for data transformation and load:
- Azure Databricks: an Apache Spark-based analytics platform optimized for Azure
- Azure Synapse Analytics: a cloud-based analytics service that brings together big data and data warehousing capabilities
- Azure Data Lake Storage Gen2: a scalable and secure cloud storage service built for big data analytics
Understanding the Components
Azure Data Factory (ADF) is a cloud-based service that enables users to create, schedule, and orchestrate data workflows at scale. It supports a variety of data sources and destinations, allowing for seamless data movement across on-premises and cloud environments.
Azure Databricks is an Apache Spark-based analytics platform optimized for Azure, providing a collaborative environment for data scientists, engineers, and analysts to work together on big data and machine learning projects. Databricks offers scalable and performant data processing capabilities, along with built-in support for languages like Python, Scala, and SQL.
Azure Synapse Analytics is a cloud-based analytics service that brings together big data and data warehousing capabilities, allowing users to analyze large volumes of data with high speed and concurrency. Synapse Analytics integrates seamlessly with other Azure services, enabling organizations to perform complex analytics, reporting, and machine learning tasks on their data.
Azure Data Lake Storage Gen2 is a scalable and secure cloud storage service built for big data analytics, providing features such as fine-grained access control, tiered storage, and high availability. With its integration with Azure services like Data Factory and Databricks, organizations can seamlessly ingest, transform, and analyze data at scale.
Here are some key features of each component:
- Azure Data Factory: data integration, scheduling, and orchestration
- Azure Databricks: Apache Spark-based analytics platform, collaborative environment for data scientists and analysts
- Azure Synapse Analytics: cloud-based analytics service, big data and data warehousing capabilities
- Azure Data Lake Storage Gen2: scalable and secure cloud storage service, fine-grained access control and tiered storage
Query Pushdown
Query pushdown is a powerful feature that can significantly improve the performance of your queries. It allows you to push certain operators down into the database, reducing the amount of data that needs to be transferred and processed.
The Azure Synapse connector supports pushdown of Filter, Project, and Limit operators. This means you can use these operators in your queries and the connector will take care of pushing them down into the database.
Some expressions are not supported for pushdown, including those operating on strings, dates, or timestamps. This is because these types of operations are typically complex and may not be optimized for pushdown.
The Project and Filter operators support a wide range of expressions, including boolean logic operators, comparisons, basic arithmetic operations, and numeric and string casts. This makes it easy to use these operators in your queries.
Here's a quick rundown of the supported expressions:
- Most boolean logic operators
- Comparisons
- Basic arithmetic operations
- Numeric and string casts
Keep in mind that the Limit operator only supports pushdown when there is no ordering specified. So, if you're using the TOP operator with an ORDER BY clause, pushdown won't be supported.
Query pushdown is enabled by default in the Azure Synapse connector, but you can disable it if needed. Simply set the spark.databricks.sqldw.pushdown property to false.
Extract and Load
After your data is in Azure, you can use various services to extract and load it into other products. HDInsight supports Sqoop and Flume, making it a convenient option.
The choice of service depends on your specific needs and the type of data you're working with. For instance, Sqoop is great for transferring data between structured, semi-structured, and unstructured data sources.
Sqoop uses MapReduce to import and export data, providing parallel operation and fault tolerance. This makes it an efficient tool for handling large datasets.
Here are some key points to keep in mind when choosing a service for extracting and loading data:
HDInsight's support for Sqoop and Flume makes it a versatile platform for data extraction and loading. With these tools at your disposal, you can efficiently transfer data between different systems and formats.
Batch Write Save Modes
Batch Write Save Modes are a crucial aspect of data transformation and load.
The Azure Synapse connector supports four save modes for batch writes: ErrorIfExists, Ignore, Append, and Overwrite.
ErrorIfExists is the default mode, which means that if a file already exists, the write operation will fail.
In contrast, the Ignore mode allows the write operation to proceed even if a file already exists, but any existing data will be overwritten.
The Append mode adds new data to the existing file without overwriting any existing data.
Overwrite mode completely replaces the existing file with the new data.
For more information on these save modes, check out the Spark SQL documentation on Save Modes.
Pipeline and Architecture
When designing a scalable ETL solution in Azure Data Factory, it's essential to consider the pipeline and architecture that will support your data processing needs. Azure Data Factory provides three architectural patterns for scalable ETL: Batch Processing, Real-time Processing, and Hybrid Processing.
Batch Processing Architecture is ideal for bulk data processing at designated times, such as nightly data warehouse loads or monthly financial reporting. This architecture is batch capable for parallel processing of large data volumes using ADF.
Real-time Processing Architecture is perfect for instant data processing, such as event-driven processing or data ingestion from IoT environments. ADF supports event-based triggers, streaming data sources, and movement activities that consume real-time data.
Hybrid Processing Architecture is a great choice for organizations with varied processing modes and diverse data sources. This architecture combines batch and real-time processing to ensure efficiency, optimized performance, and scalability.
Pipeline Anatomy
An ETL pipeline is a series of steps that extract, transform, and load data. In the context of Azure, it's a helpful window into the specifics of Microsoft's data integration service.
Data extraction is the first step in an ETL pipeline, and it involves retrieving data from sources like Azure SQL Database, Azure Cosmos DB, or a file system like Azure Blob Storage. ADF allows for extraction from external platforms and services, but users must create linked services to connect to targeted data sources and datasets.
Data transformation is a crucial part of the ETL process, and it involves converting extracted data into suitable formats for reporting or analysis. This typically includes common functions like data cleaning and filtering, aggregation from various sources, and restructuring.
Data transformation can be performed using data flows or integrations with other Azure services like Azure HDInsight for Hive, MapReduce jobs, or Azure Databricks for Spark-based transformations. Some use cases require additional functionality, such as converting data types or applying business logic and null values.
Data loading is the final step in an ETL pipeline, and it involves loading transformed data into a targeted data store. Within the Microsoft Azure ecosystem, this could be Azure Data Lake Storage, Azure SQL Database, or Azure Synapse Analytics. ADF will typically use copy activities to orchestrate this final phase of the ETL pipeline process.
Here's a breakdown of the ETL pipeline steps:
- Data extraction: Retrieve data from sources like Azure SQL Database, Azure Cosmos DB, or a file system like Azure Blob Storage.
- Data transformation: Convert extracted data into suitable formats for reporting or analysis.
- Data loading: Load transformed data into a targeted data store, such as Azure Data Lake Storage, Azure SQL Database, or Azure Synapse Analytics.
Pipeline Distinctions
Azure Data Factory offers several pipeline distinctions that set it apart from other ETL tools. One notable distinction is its cloud-native integration with other Azure services, allowing seamless integration with tools like Azure SQL Data Warehouse and Azure Blob Storage.
This integration can be both a benefit and a drawback, depending on your organization's existing infrastructure. If you're already invested in the Azure ecosystem, this integration is a major advantage.
Azure Data Factory's management and monitoring capabilities are also robust, thanks to its integration with Azure Management and Governance, and Azure Monitor. This provides users with a high level of control and visibility over their ETL pipelines.
ADF's integration with Azure DevOps enables continuous integration and delivery (CI/CD), allowing for automated deployment and testing of ETL pipelines. This streamlines the development process and reduces the risk of errors.
The integration runtimes offered by Azure Data Factory, including Azure, Azure-SSIS, and self-hosted, enable hybrid ETL scenarios where data can be moved across different environments. This flexibility is a major advantage for teams working with diverse data sources.
Serverless compute is another key benefit of using Azure Data Factory, as it eliminates the need for infrastructure management and reduces costs. This makes it an attractive option for teams with limited resources.
Azure Data Factory's extensibility features, including the ability to incorporate custom code and logic using Azure Functions, make it a versatile tool for ETL processes. This allows teams to tailor their pipelines to meet their specific needs.
The integration with Power BI provides users with easy reporting and analytics on their processed data, making it a valuable addition to the Azure Data Factory ecosystem.
Frequently Asked Questions
What is the best ETL tool for Azure?
The best ETL tool for Azure depends on your specific needs, but popular options include Azure Data Factory and Azure Databricks, both offering robust data integration and processing capabilities.
Is Azure Databricks an ETL tool?
Azure Databricks offers a powerful ETL experience with tools like Apache Spark, Delta Lake, and custom tools. It enables users to compose and orchestrate ETL logic with ease using SQL, Python, and Scala.
Is Azure Synapse an ETL?
Yes, Azure Synapse offers ETL (extract, transform, load) capabilities as part of its powerful data integration and analytics platform. Learn more about its ETL features and how they compare to other solutions.
Sources
- https://blog.stackademic.com/building-an-end-to-end-etl-pipeline-with-azure-data-factory-azure-databricks-and-azure-synapse-0dc9dde0a5fb
- https://learn.microsoft.com/en-us/azure/databricks/scenarios/databricks-extract-load-sql-data-warehouse
- https://learn.microsoft.com/en-us/azure/hdinsight/hadoop/apache-hadoop-etl-at-scale
- https://www.shipyardapp.com/blog/azure-data-pipelines/
- https://www.aegissofttech.com/insights/etl-processes-azure-data-factory/
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