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Databases · head to head

Apache Solr vs ClearML

Apache Solr logo

Apache Solr

Databases

Enterprise search platform built on Apache Lucene

From
Free
Rated
-
Full reviewWebsite
ClearML logo

ClearML

Machine Learning

Open-source MLOps platform for experiment tracking and orchestration

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Apache Solr xML-heavy configuration and a developer experience that feels dated beside newer engines; ClearML broad scope means more to learn and more to run than a focused tracking tool
  • They diverge on capability: Apache Solr covers Lucene-based indexing, ClearML covers Experiment tracking.
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Apache Solr and ClearML actually diverge.

Attributes where Apache Solr and ClearML differ
AttributeApache SolrClearML
Pricing modelOpen source, no licence feeOpen-source self-hosted, with paid hosted and enterprise tiers
PlatformsLinux, Docker, Kubernetes, Self-hostedLinux, macOS, Windows, Docker, Kubernetes
CategoryDatabasesMachine Learning

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Apache Solr

  • Lucene-based indexing
  • Faceted search
  • SolrCloud
  • Schema control

Only in ClearML

  • Experiment tracking
  • Remote execution
  • Data versioning
  • Pipelines

What people use each for

The jobs each tool is most often brought in to do.

Apache Solr

  • Library, archive and catalogue search where faceting is centralnot ClearML
  • Long-lived enterprise deployments valuing stability over noveltynot ClearML
  • Search requiring precise, explicitly configured relevance tuningnot ClearML

ClearML

  • Tracking experiments across a team so results are reproduciblenot Apache Solr
  • Moving training from laptops to shared GPU hardware without repackagingnot Apache Solr
  • Versioning datasets alongside the experiments that consumed themnot Apache Solr

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Apache Solr

  • XML-heavy configuration and a developer experience that feels dated beside newer engines
  • SolrCloud depends on ZooKeeper, adding a component Elasticsearch removed years ago
  • Smaller mindshare now, so newer tutorials, hiring and integrations favour Elasticsearch
  • Considerably heavier than a purpose-built application search engine

ClearML

  • Broad scope means more to learn and more to run than a focused tracking tool
  • Self-hosting the server is real infrastructure — database, file storage and web server
  • Documentation quality is uneven across the newer parts of the platform
  • Smaller community than the most popular tracking tools, so fewer worked examples exist

Pricing, plan by plan

Apache Solr

Free
  • Apache SolrFree
    • Full functionality
    • No usage limits
    • Community support

ClearML

Free
  • Open sourceFree
    • Experiment tracking
    • Pipelines
    • Self-hosted server

Which should you pick?

Choose Apache Solr if

  • You need lucene-based indexing.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want faceted search.
Apache Solr review

Choose ClearML if

  • You need experiment tracking.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Kubernetes.
  • You also want remote execution.
ClearML review

Questions people ask

Is Apache Solr or ClearML better?
Neither clearly leads. Apache Solr starts at Free and ClearML at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Apache Solr or ClearML?
Apache Solr starts at Free and ClearML at Free.
Does Apache Solr or ClearML run on more platforms?
Apache Solr runs on Linux, Docker, Kubernetes, Self-hosted. ClearML runs on Linux, macOS, Windows, Docker, Kubernetes.
Can I use Apache Solr for free?
Both have a free tier, so you can try either at no cost before committing.
What is Apache Solr best used for?
Apache Solr is most often used for library, archive and catalogue search where faceting is central, long-lived enterprise deployments valuing stability over novelty, search requiring precise, explicitly configured relevance tuning. Of those, library, archive and catalogue search where faceting is central and long-lived enterprise deployments valuing stability over novelty are not what ClearML is typically brought in for.
What can Apache Solr do that ClearML cannot?
Apache Solr covers Lucene-based indexing, Faceted search, SolrCloud, Schema control. ClearML covers Experiment tracking, Remote execution, Data versioning, Pipelines.

Answered from the vendors’ own pages

Apache Solr: Is Apache Solr free?

Yes, open source under the Apache Software Foundation.

ClearML: Is ClearML free?

The open-source version is free and self-hostable. Hosted and enterprise tiers are paid.

Apache Solr: Solr or Elasticsearch?

Both are built on Lucene. Elasticsearch has the larger ecosystem and a friendlier API; Solr is very mature and strong on faceted search, and remains common in library and catalogue systems.

ClearML: How much code does tracking require?

Very little — adding a couple of lines to an existing training script captures parameters, metrics and environment automatically.

Apache Solr: Is Solr still maintained?

Yes, actively, as a top-level Apache project.

ClearML: Does ClearML replace MLflow?

It covers MLflow’s tracking and adds orchestration, remote execution and data versioning. Whether that breadth is an advantage or extra weight depends on whether you need the rest.

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