The document discusses challenges in building a data pipeline including making it highly scalable, available with low latency and zero data loss while supporting multiple data sources. It covers expectations around real-time vs batch processing and streaming vs batch data. Implementation approaches like ETL vs ELT are examined along with replication modes, challenges around schema changes and NoSQL. Effective implementations should address transformations, security, replays, monitoring and more. Reference architectures like Lambda and Kappa are briefly outlined.

1. Manish Singh
Engineer at Hevo
https://linkedin.com/in/manishsingh123/
Challenges in Building a
Data Pipeline

2. ● Data Pipeline
● Possible Implementations
● Challenges
● Data Processing Architectures
Agenda

3. ● Highly scalable
● Highly available
● Low latency
● Zero data loss
● Support for multiple data sources (e.g. MySQL, NoSQL,
Mixpanel, Analytics)
● Instrumentation, monitoring, and alerting
● Real-time vs Batch
Expectations

4. Stream
● Usages: Live dashboards
(count, average), rate
limiting, triggers
● Processing: Apache Storm,
Apache Spark, Apache
Samza
● Store: Elastic Search, Druid,
Spark SQL, Kafka SQL
Stream vs Batch
Batch
● Batch Processing
and
pre-computation
● Immutable Store: HDFS,
Cassandra, Event Stream to
S3
● Data Warehouse: HBase,
Hive, Redshift, Postgres

5. ● ETL (Extract -> Transform -> Load)
● ELT (Extract -> Load -> Transform)
ETL vs ELT

7. ● Complexity of transformation logic compromises latency
● Hardware systems today are better equipped
● Efficient, reduces load time
● Cost effective in the cloud, less components required
Moving from traditional ETL
to ELT

8. ● Query Source DB and keep offset (ID, Updated timestamp)
● Database change logs (e.g. Mysql Binlogs, MongoDB Oplogs)
Replication Modes

9. ● New fields can be added to a source at any point in time
● Character lengths of String columns in source can increase
● Data Type incompatibility between Source and Destination
● Varying type casting
● Data loss during loads - Power failure, Server failure, Code
bugs, etc
Challenges

10. ● Schema detection cannot be done upfront
● Different documents in a single collection can have a different
set of fields
● Different documents in a single collection can have
incompatible field data types
● Nested objects and arrays with a dynamic structure
Additional Challenges with
NoSQL

11. ● Transformations
● Security (Filter, Hashing)
● Replay Mechanism
● Integrity and Anomaly Detection
● Monitoring and Alerts for failures
● Activity Log
Effective Implementations

14. ● How to beat the CAP theorem by Nathan Marz
● Different layers for stream and batch processing
● Need to manage two different layers of the system
Lambda Architecture

15. Lambda Architecture

16. ● Questioning the Lambda Architecture by Jay Kreps
● Only stream processing with parallelism
● Set Kafka retention policy
● Reprocess into separate table
● Switch table when done and delete the old one
Kappa Architecture

17. Kappa Architecture

18. Questions?

19. Thank You
Manish Singh, Hevo
https://linkedin.com/in/manishsingh123/