Reading S3 parquet file with zstd compression in Lambda

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Summary

The issue at hand is reading parquet files with zstd compression in an AWS Lambda function. The error messages indicate a lack of support for the zstd codec and S3 support in Arrow. Despite creating a Lambda layer for zstd, the error persists.

Root Cause

The root cause of this issue is:

  • Incomplete support for zstd compression in the libraries used (e.g., pandas, pyarrow)
  • Missing S3 support in Arrow, which is required for reading parquet files from S3
  • Inadequate configuration of Lambda layers, which fails to provide the necessary support for zstd compression

Why This Happens in Real Systems

This issue occurs in real systems due to:

  • Incompatible library versions, which may not support the latest compression algorithms or S3 features
  • Insufficient configuration of dependencies, leading to missing support for certain codecs or storage systems
  • Limited resources in serverless environments, such as AWS Lambda, which can restrict the availability of certain libraries or features

Real-World Impact

The impact of this issue includes:

  • Failed data processing pipelines, which rely on reading parquet files from S3
  • Inability to leverage serverless computing, which can lead to increased costs and complexity
  • Delays in data analysis and insights, which can affect business decision-making and competitiveness

Example or Code (if necessary and relevant)

import boto3
import pyarrow.parquet as pq
import s3fs

s3 = boto3.client('s3')
s3fs = s3fs.S3FileSystem()

# Define the S3 path and file name
s3_path = 's3://my-bucket/my-file.parquet'

# Read the parquet file using pyarrow and s3fs
fs = s3fs.S3FileSystem()
file = fs.open(s3_path, 'rb')
df = pq.read_table(file).to_pandas()

How Senior Engineers Fix It

Senior engineers fix this issue by:

  • Verifying library versions and compatibility, ensuring that the latest versions are used
  • Configuring dependencies and Lambda layers correctly, providing the necessary support for zstd compression and S3
  • Using alternative libraries or approaches, such as pyarrow and s3fs, to read parquet files from S3
  • Optimizing serverless environments, leveraging the strengths of AWS Lambda while mitigating its limitations

Why Juniors Miss It

Junior engineers may miss this issue due to:

  • Lack of experience with serverless computing, which can lead to unfamiliarity with AWS Lambda and its limitations
  • Insufficient knowledge of library versions and compatibility, resulting in incompatible dependencies
  • Inadequate understanding of compression algorithms and storage systems, which can lead to incorrect configuration of Lambda layers and dependencies
  • Overreliance on high-level libraries, which may not provide the necessary low-level control for reading parquet files from S3