A Hadoop data lake is a centralized repository that stores raw, unprocessed data in its native format, allowing for easy access and analysis.
This approach is a departure from traditional data warehousing, which involves processing and transforming data before storing it.
Data lakes are designed to handle large volumes of data from various sources, including structured, semi-structured, and unstructured data.
By storing data in its native format, data lakes enable organizations to retain the original context and relationships between data elements.
What Is a Data Lake?
A data lake is essentially a centralized repository that stores raw, unstructured data in its native format. This allows for easy ingestion and storage of various data types.
Data lakes are designed to handle large volumes of data from different sources, making them a great solution for big data analytics. They provide a flexible storage solution for unstructured data.
One of the key benefits of data lakes is that they can store data in its raw form, without the need for transformation or processing. This makes it easier to analyze and gain insights from the data.
Data lakehouses, a hybrid approach, combine the best of both worlds by adding data warehouse capabilities to the data lake. They provide ACID transactions, schema enforcement, governance, and support for diverse workloads.
Here are some key characteristics of data lakes:
- Data management
- Cloud storage
Benefits and Advantages
A data lake offers unmatched scale and flexibility, allowing you to process data using various technologies, tools, and programming languages.
Resource optimization is a significant advantage of data lakes, as they decouple cheap storage from expensive compute resources, making them cheaper than databases when working with high scales.
With data lakes, you can store data in its native raw form, without any transformation or structuring, making it easy to add new sources or modify existing ones without building custom pipelines.
Data lakes give organizations more flexibility in how they eventually choose to work with the data, supporting a broader range of use cases, since you are not limited by the way you chose to structure your data upon its ingestion.
Here are some key benefits of data lakes:
- Speed
- Flexibility
- Scale at low cost
- Resilience and fault tolerance
Data lakes are flexible and scalable, allowing you to store data in any format and scale up or down as needed. This makes them perfect for machine learning and data science applications.
Data lakes enable team collaboration and data shareability, with self-service architecture and in-depth metadata allowing different teams to get relevant domain knowledge and ensure consistency.
The schema-on-read architecture of data lakes automatically applies a relevant schema on data upon request, making unstructured data analysis easier and more efficient.
Data lakes can ingest data from any source in native format, eliminating the need for complex transformation pipelines at the ingestion stage.
Here are some examples of use cases that data lakes enable:
- Sentiment analysis
- Fraud detection and prediction
- Natural language processing
- Rapid prototyping
- Recommendation engines
- Personalized marketing
Data lakes decouple storage from compute, making working with large amounts of data much more cost-effective compared to storing the same amount of data in a database.
Architecture and Components
A data lake platform is essentially a single platform that takes care of everything from data management and storage to processing, ETL jobs, and outputs, making it easier to manage complex data operations.
This platform enforces dozens of best practices, replacing manual coding with automated actions managed through a GUI, and improving performance and resource utilization throughout storage, processing, and serving layers.
A data lake architecture typically encompasses schema discovery, metadata management, and data modeling, connecting the dots from data ingested to a complete analytics solution. This framework involves complex tasks and multiple components such as Apache Spark, Apache Kafka, and Apache Hadoop.
Data lakes can be built using multiple vendors or proprietary technology, and while there is no single list of tools every data lake must include, core components can be expected to include data ingestion, ETL processes, and services for querying and analyzing the data.
Resilience and Fault Tolerance
Data lakes are designed to be highly resilient and fault-tolerant, thanks to their distributed nature. This means that if an error occurs, it's less likely to affect the entire system.
Data lakes are often configured on a cluster of scalable commodity hardware, typically in the cloud. This allows them to handle large volumes of data and scale as needed.
Storing historical data is a key aspect of data lakes, and it ensures accuracy by providing a record of past events. This also enables replay and recovery from failure.
Data lakes can live on-premises, but they're increasingly being deployed in the cloud due to the scalability and cost-effectiveness it offers.
Platform Components
A data lake platform is a crucial part of any architecture, and it's essential to understand its components.
Apache Spark, Apache Kafka, and Apache Hadoop are complex components that are often used in data lake architectures, along with techniques like ETL or ELT pipelines. These components play a critical role in massaging streams of unstructured data to make it accessible.
In a typical data lake architecture, you'll find schema discovery, metadata management, and data modeling. These components work together to connect the dots from data ingested to a complete analytics solution.
Here are some key components of a data lake platform:
- Unifying data lake operations and combining building blocks
- Enforcing best practices, such as automated actions managed through a GUI
- Improving performance and resource utilization throughout storage, processing, and serving layers
- Providing governance and visual data management tools
Hadoop data lakes use the Hadoop framework to store, process, and analyze big data. This framework is an open-source platform that uses clusters to manage data, making it a popular choice for data lake architectures.
Data Storage and Analysis
A data lake allows you to store vast streams of real-time transactional data as well as virtually unlimited historical data coming in as batches. This makes it ideal for storing data just in case you may someday need it, without caring about storage capacity.
The data lake approach separates storage from analysis, storing data as-is and schema-less. This is a sharp deviation from traditional analytics, where data is structured according to a specific use case.
You can store relational data in table formats, as well as non-relational data from mobile apps, videos, audio, IoT sensors, social media, and JSON or CSV files.
Speed
Data lakes are a game-changer when it comes to storing vast amounts of data. They can handle virtually unlimited historical data coming in as batches.
You can store data just in case you may someday need it, without worrying about storage capacity. This is especially useful for storing real-time transactional data that's constantly flowing in.
Data scientists can find, access, and analyze data more quickly and accurately with data lakes. This is because the lack of strict metadata management enables faster data writes.
Here are some key benefits of data lakes when it comes to speed:
- Data lakes can store vast streams of real-time transactional data.
- They can handle virtually unlimited historical data coming in as batches.
- Data scientists can find, access, and analyze data more quickly and accurately.
Accessing Adl URLs
Accessing Adl URLs is a straightforward process once your credentials are configured in core-site.xml. The adl scheme identifies a URL on a Hadoop-compatible file system backed by Azure Data Lake Storage.
Any Hadoop component can reference files in your Azure Data Lake Storage account by using URLs of the adl format. This format utilizes encrypted HTTPS access for all interaction with the Azure Data Lake Storage API.
To access your storage account, you can use the FileSystem Shell commands. For example, the following command demonstrates access to a storage account named youraccount.
Store Now, Analyze Later
The "Store Now, Analyze Later" approach is a game-changer for data storage and analysis. This method allows you to separate storage from analysis, which is a sharp deviation from traditional analytics.
Data lakes ingest streams of structured, semi-structured, and unstructured data sources, and store the data as-is and schema-less. This means you don't have to worry about transforming the data at the ingestion stage.
A traditional data lake can store relational data in table formats, as well as non-relational data from mobile apps, videos, audio, IoT sensors, social media, and JSON or CSV files. This makes it a versatile storage solution.
Data lakes can ingest data from any source in native format, which means you don't have to build complex transformation pipelines. This also means the schema-on-read method automatically applies a relevant schema on data upon request, making unstructured data analysis easier.
Data lakes are ideally suited for storing vast streams of real-time transactional data as well as virtually unlimited historical data coming in as batches. This allows you to store data just in case you may someday need it, without worrying about storage capacity.
Data scientists can find, access, and analyze data more quickly and accurately, as the lack of strict metadata management enables faster data writes. This is especially useful when you're not sure exactly what you're looking for.
Here are some key benefits of the "Store Now, Analyze Later" approach:
- Separates storage from analysis
- Stores data in native format
- Automatically applies schema on read
- Enables faster data writes
Real-Time
A real-time data lake is designed to ingest data continuously from various sources.
This is because data is being generated constantly by endpoints like IoT sensors, the internet, and consumer apps.
In a real-time data lake, data can be ingested in any format from any source, thanks to its schema-less nature.
This means you can store and analyze data from a wide range of sources, from social media to sensor readings.
Real-time data lakes operate in real-time to capture data from these constantly producing sources.
This is a must-have for applications that rely on up-to-the-second data, like financial trading platforms or emergency response systems.
Management and Integration
Data lakes can integrate with various data sources, including mobile apps, IoT sensor data, and internal business applications. These sources can be in different formats, such as unstructured data like images and videos, semi-structured data like CSV and JSON files, and structured data like tables.
Managing large volumes of data is time-consuming and costly, but data lakes simplify processing data through metadata management. Metadata is data about your data, and it can provide domain-specific knowledge, information about the creators, date of creation, recent updates, data formats, and more.
Data lakes automate metadata management by assigning definitions to data according to a business glossary. This saves time and increases data shareability, breaking down data silos and improving collaboration.
Is a Database?
A data lake is not a database, despite both storing data. Data lakes store historical and current data, whereas databases store only current data.
You need a database management system (DBMS) to operate a database, which is not required for a data lake. Several database types exist, but a data lake can store data in database tables without a predefined structure.
A database has a predefined schema, which means it stores structured or semi-structured data in a specific format, like a relational database's tabular format. This is in contrast to a data lake, which can store several data types.
A data lake's ability to store multiple data types gives it better analytical capabilities compared to a database.
OAuth2 Support
To use Azure Data Lake Storage, you need an OAuth2 bearer token in the HTTPS header as per the OAuth2 specification.
Azure Active Directory (Azure AD) is the service that provides valid OAuth2 bearer tokens for users with access to Azure Data Lake Storage Account.
You can obtain a valid OAuth2 bearer token from Azure AD.
A valid OAuth2 bearer token must be obtained from Azure Active Directory service.
Azure AD is Microsoft's multi-tenant cloud-based directory and identity management service.
You can find more information about Azure AD in the What is Active Directory section.
Following the OAuth2 configuration in core-site.xml is essential for Azure Data Lake Storage.
Sources and Integration
Data sources can include mobile apps, IoT sensor data, the internet, and internal business applications.
These sources can be in different formats, such as unstructured data like images, video, emails, and audio.
Data can also come in semi-structured formats like CSV or JSON files.
Structured data can be found in table formats.
Sources can be integrated with your data lake, allowing you to collect and store data from various sources in one place.
This integration is crucial for getting a complete picture of your data and making informed decisions.
Management
Managing large volumes of data can be a real challenge, but data lakes simplify processing data through metadata management. This means you can easily understand the meaning of each column in a table.
Metadata is data about your data, and it can provide domain-specific knowledge, information about the creators, date of creation, recent updates, data formats, and more. Data lakes automate metadata management, saving you time and effort.
Domain teams can manage access to their data assets themselves, without relying on a central IT administrator. This saves time and increases data shareability, breaking down data silos and promoting better collaboration.
Object storage is different from file and block storage methods. It stores data in a hierarchical format, but doesn't require a complete path to find the relevant data.
Data lakes are highly scalable and provide superior analytical capabilities, making them a crucial tool for every business. They can ingest structured and unstructured data from several sources, such as mobile apps, IoT devices, and the web.
Having strong governance procedures in place can help prevent data lakes from becoming swamps, even with large data volumes from many sources. This ensures that data is properly managed and accessible to those who need it.
Finance
In finance, data lakes can be used to collect extensive economic, political, and financial data.
Financial institutions can analyze credit ratings of potential borrowers more accurately by examining their historical financial and general socio-economic data.
Banks can use data lakes to measure default risk by examining a borrower's historical financial data.
Financial institutions can predict movements in stock prices using historical movements in stock prices, interest rates, and macroeconomic indicators stored in data lakes.
Data lakes enable banks to capture public sentiments against a political regime using social media, which can be used to inform financial decisions.
User/Group Representation
User/Group Representation is a crucial aspect of managing and integrating data. The hadoop-azure-datalake module provides support for configuring how User/Group information is represented during getFileStatus(), listStatus(), and getAclStatus() calls.
To configure User/Group representation, you need to add the following properties to core-site.xml. This is a straightforward process that requires attention to detail.
The properties to add are not specified in the provided article section facts, so let's focus on the existing information. The hadoop-azure-datalake module provides support for configuring User/Group information representation.
In order to take advantage of this feature, you need to have the hadoop-azure-datalake module installed and configured properly. This will allow you to leverage the full potential of User/Group representation in your data management and integration efforts.
The hadoop-azure-datalake module provides support for configuring how User/Group information is represented during getFileStatus(), listStatus(), and getAclStatus() calls.
Frequently Asked Questions
Is HDFS a data lake or data warehouse?
HDFS is a storage layer that serves as a landing zone for a data lake, not a data warehouse. It's a cost-effective solution for storing and querying both structured and unstructured data.
Is Azure Data Lake based on Hadoop?
Azure Data Lake Storage is built on top of the Hadoop Distributed File System (HDFS), allowing seamless integration with Hadoop-based tools. This compatibility makes it easy to migrate existing Hadoop workflows to Azure Data Lake Storage.
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