Apache Solr vs Milvus
A side-by-side comparison of two self-hosted search engines options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Apache Solr | Milvus |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 81 · Excellent | 100 · Excellent |
| Category | Search Engines | Search Engines |
| License | Apache-2.0 | Apache-2.0 |
| Language | Java | Go |
| Setup difficulty | Hard | Hard |
| Min. RAM | 1,024 MB | 4,096 MB |
| Deployment | docker, kubernetes, bare-metal | docker, kubernetes, helm |
| GitHub stars | ★ 1,674 | ★ 46,245 |
| First released | 2006 | 2019 |
| Replaces | Elasticsearch, Algolia | Pinecone, Elasticsearch |
What are Apache Solr and Milvus?
Apache Solr
Apache Solr is a highly reliable, scalable and fault-tolerant open-source search platform built on Apache Lucene. It powers full-text search, faceting and analytics for many large websites and applications.
- Lucene-powered full-text search
- Faceting and rich querying
- Distributed SolrCloud mode
- Extensive plugin ecosystem
Milvus
Milvus is an open-source vector database designed for scalable similarity search and AI applications. It can manage billions of vectors and supports semantic search and recommendation use cases.
- Billion-scale vector search
- Multiple index types
- Cloud-native distributed architecture
- Hybrid search support
Apache Solr vs Milvus: key differences
Apache Solr is written in Java, while Milvus is built with Go. Apache Solr is the lighter option, starting around 1,024 MB of RAM against 4,096 MB for Milvus. Apache Solr is the more established project (first released 2006), while Milvus arrived in 2019. Milvus has the considerably larger community, at 46,245 GitHub stars versus 1,674.
Why pick each one
Choose Apache Solr if…
- Mature and battle-tested
- Powerful faceting
Watch out for
- Configuration is complex
Choose Milvus if…
- Scales to massive datasets
- Mature vector ecosystem
Watch out for
- Complex distributed deployment
Frequently asked questions
Is Apache Solr or Milvus better?
Neither is universally better. Milvus has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Apache Solr and Milvus free and open-source?
Yes. Apache Solr is licensed under Apache-2.0 and Milvus under Apache-2.0. Both can be self-hosted at no software cost.
Can I run Apache Solr and Milvus with Docker?
Apache Solr: yes. Milvus: yes.
Which is lighter on resources, Apache Solr or Milvus?
Apache Solr has the smaller minimum footprint at 1,024 MB of RAM, compared to about 4,096 MB for Milvus. Real-world usage depends on library size, user count, and enabled features.