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Open-Source Observability · whylabs

whylogs

whylogs is an open-source data logging library that captures statistical profiles of datasets to detect data quality issues, drift, and performance degradation in ML systems. It provides efficient, mergeable summaries of data distributions and enables constraint-based validation without storing raw data.

Source: GitHub — github.com/whylabs/whylogs
2.8k
GitHub stars
143
Forks
Jupyter Notebook
Primary language
Apache-2.0
License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

FieldValue
Repositorywhylabs/whylogs
Ownerwhylabs
Primary languageJupyter Notebook
LicenseApache-2.0 — OSI-approved
Stars2.8k
Forks143
Open issues4
Latest releasev1.6.4 (2024-12-03)
Last updated2025-01-10
Sourcehttps://github.com/whylabs/whylogs

What whylogs is

whylogs generates compact, mergeable statistical profiles from dataframes and complex data types, supporting custom metrics, data constraints, and visualization. Profiles can be locally analyzed or sent to the WhyLabs SaaS platform for automated ML monitoring and observability.

Quickstart

Get the whylogs source

Clone the repository and explore it locally.

terminalbash
git clone https://github.com/whylabs/whylogs.gitcd whylogs# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Data Drift & Model Performance Monitoring

Track changes in feature distributions and detect training-serving skew, concept drift, and model degradation over time without storing raw data.

Data Quality Validation in Pipelines

Set data constraints to validate schema, missing values, and statistical properties at ingestion points; enable early detection of upstream data quality failures.

Exploratory Data Analysis at Scale

Generate summary statistics and visualizations of massive datasets efficiently, enabling rapid understanding of data characteristics without sampling.

Implementation considerations

  • Profiles are mergeable but not queryable like a database; plan storage and retrieval strategy for historical profiles (local, cloud, or WhyLabs).
  • Customizable metrics allow tracking domain-specific statistics but require upfront definition of constraints and KPIs.
  • Performance depends on dataset size and column cardinality; approximate statistics and sampling strategies can optimize for large-scale data.
  • Integration with WhyLabs unlocks alerting and dashboards; decide early whether standalone profiling or managed monitoring aligns with operational model.
  • Slack community available but enterprise support / SLAs are Unknown; review WhyLabs commercial terms if production monitoring is required.

When to avoid it — and what to weigh

  • Need Row-Level Data Access — whylogs profiles are summaries; individual records are not stored. If you need to inspect or replay raw data, use a data lake or data warehouse.
  • Require Real-Time Sub-Second Latency — Profile generation adds computational overhead. For ultra-low-latency streaming (sub-100ms), evaluate lightweight alternatives or pre-aggregation strategies.
  • Exclusively Java/Non-Python Environments — Primary language is Jupyter Notebook/Python; Java support exists but may lag feature parity. Multi-language teams should verify integration depth.
  • Need Offline, Air-Gapped Deployment — WhyLabs SaaS integration is a core feature; using whylogs in standalone mode is possible but reduces value. Evaluate dependency on cloud connectivity.

License & commercial use

Apache License 2.0 (Apache-2.0) is a permissive OSI-approved open-source license. It allows use in commercial products, with no copyleft requirement, but requires retention of license notices and provides no warranty.

Apache-2.0 permits commercial deployment without royalties or restrictions on derived works. However, WhyLabs integration (core feature) relies on a separate SaaS subscription model; review WhyLabs commercial terms separately. Standalone use is unrestricted by license.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

SignalAssessment
MaintenanceActive
DocumentationAdequate
License clarityClear
Deployment complexityLow
DEV.co fitGood
Assessment confidenceHigh
Security considerations

whylogs is privacy-preserving by design—profiles are statistical summaries, not raw data storage, reducing exposure. However: profile export formats, WhyLabs data transmission, and API key management are security touch points—review credential handling and network egress. No independent security audit referenced in provided data.

Alternatives to consider

Great Expectations

Data validation framework with richer constraint definition and integration with data catalogs; more heavyweight if you need full pipeline data contracts.

Evidently

Similar data drift and model monitoring focus, with built-in dashboards; more tightly coupled to model performance metrics, less modular than whylogs.

Fiddler AI

Managed SaaS ML monitoring platform; consider if you want off-the-shelf hosted solution without building on whylogs + WhyLabs.

Software development agency

Build on whylogs with DEV.co software developers

whylogs enables efficient data profiling and drift detection in ML pipelines. Evaluate integration with your data stack, decide on standalone vs. WhyLabs SaaS, and pilot with a single feature.

Talk to DEV.co

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whylogs FAQ

Can I use whylogs without WhyLabs?
Yes. whylogs profiles can be generated, stored locally, and analyzed standalone. WhyLabs integration is optional and provides managed monitoring/alerting.
What data types does whylogs support?
Pandas DataFrames natively; custom trackers for text, images, and other complex types. Exact coverage requires review of current plugin ecosystem.
Is whylogs suitable for streaming data?
Yes, profiles are mergeable, enabling incremental updates from streaming systems. Performance at extreme throughput (> 1M events/sec) is Unknown.
How large can profiles be, and does size affect performance?
Profiles are compact by design but cardinality and custom metrics increase size. Large-scale deployments should benchmark with production data schemas.

Custom software development services

Adopting whylogs is usually one piece of a larger software development effort. As a software development agency, DEV.co provides software development services and web development expertise — pairing senior software developers and web developers with your team to design, build, and operate open-source observability software in production.

Ready to Add Data Observability?

whylogs enables efficient data profiling and drift detection in ML pipelines. Evaluate integration with your data stack, decide on standalone vs. WhyLabs SaaS, and pilot with a single feature.