Data Ingestion
Table of Contents
1. Overview
1.1. Definition:
Data ingestion refers to the process of transporting data from various sources to a storage medium where it can be accessed, used, and analyzed.
1.2. Sources of Data:
1.3. Data Formats:
- Data ingestion tools must handle multiple data formats, including structured, unstructured, and semi-structured data formats like JSON, CSV, XML, Avro, Parquet, etc.
1.4. Types
1.4.1. Temporality:
- Batch Processing
- Definition: Data is collected over a period, then processed as a single unit or batch.
- Latency: Typically associated with high latency, as it waits for a complete dataset before processing.
- Use Cases: Ideal for scenarios where up-to-date data is not crucial, such as end-of-day reporting, ETL processes, and periodic data integrations.
- Scalability: Generally scalable for large volumes of data, since processing can be done in bulk.
- Complexity: Simpler to implement in comparison to streaming, often utilizing traditional databases and data warehouses.
- Streaming Processing
- Definition: Data is processed in real-time or near-real-time as it arrives.
- Latency: Low latency, providing immediate or timely processing of information.
- Use Cases: Suited for applications requiring instant data processing like fraud detection, live event monitoring, and online recommendation systems.
- Scalability: Can handle continuous data flows which may require distributed processing systems to scale effectively.
- Complexity: More complex to implement due to the requirement of managing data flow, consistency, and processing order.
- Connections and Considerations:
- Data Volume & Velocity: Batch is preferable for high-volume, less frequent transactions, whereas streaming better handles continuous flows of data.
- Data Consistency & Accuracy: Consider how eventual consistency or exactly-once semantics would impact your application; these are more challenging to guarantee in streaming systems.
- Infrastructure & Cost: Streaming might require more sophisticated and potentially costly infrastructure to maintain low latency.
- Business Needs: Analyze whether the nature of your business operations aligns more closely with periodic updates or ongoing, real-time data insights.
1.4.2. Mechanisms
- Push
- Definition: Data is sent from the source to the destination proactively.
- Use Cases: Suitable for real-time or near-real-time data applications.
- Advantages:
- Lower latency since data is sent as soon as it's available.
- Simplicity for the source as it only needs to send data to the target.
- Disadvantages:
- More complex error handling required by the destination to manage unexpected data arrival.
- Potentially more challenging to scale if the source needs to send data to multiple destinations.
- Pull
- Definition: The destination requests and retrieves data from the source.
- Use Cases: Ideal for periodic batch data processing.
- Advantages:
- The destination controls the rate and timing of data retrieval, simplifying error management and processing.
- Easier to manage retries and failed data retrievals.
- Disadvantages:
- Higher latency, as data is retrieved based on the destination's schedule.
- Increased complexity on the destination side, as it must implement scheduling and data checking mechanisms.
- Connections and Considerations
- Latency: Push systems generally have lower latency than pull systems since they send data immediately upon availability.
- Scalability: Pull systems might offer better scalability if multiple consumers are polling from the same source, while push systems can become complex if the source pushes data to many destinations.
- Resource Management: Push systems require proactive resource management by the source, while pull systems require it by the destination.
- Error Handling: Pull systems often have built-in mechanisms to handle intermittent retrieval failures, while push systems require robust error-handling frameworks at the
1.5. Challenges in Data Ingestion:
- Scalability: Managing increasing volumes of data efficiently.
- Data Quality: Ensuring the accuracy and consistency of data being ingested.
- Latency: Minimizing delays from data source to destination.
- Security: Protecting data during ingestion from unauthorized access or corruption.
1.6. Best Practices:
- Ensuring data quality and cleansing before ingestion.
- Implementing robust error handling mechanisms.
- Using scalable solutions that can adapt to growing data inflows.
- Monitoring the ingestion process continuously to detect and fix issues early.
2. Misc
2.1. Key Engineering Considerations for Ingestion Phase
- What are the use cases for the data I'm ingesting?
- Can I use this data rather than creating multiple version of the same dataset?
- Are the systems generating and ingesting this data reliably, and is the data available when I need it?
- What is the data destination after ingestion?
- How frequently will I need to access the data?
- In what volume will the data typically arrive?
- What format is the data in? Can my downstream storage and transformation systems handle this format?
- Is the source data in good shape for immediate downstream use? If so, for how long, and what may cause it to be unusable?
- If the data is from a streaming source, does it need to be transformed before reaching its destination? Would an in-flight transformation be appropriate, where the data is transformed within the stream itself?