solr
Apache Solr is an open-source search engine built on Apache Lucene that handles full-text, vector, and geospatial search at scale. It's a mature Java project widely used in enterprise environments and supports deployment on standard infrastructure, Docker, and Kubernetes.
Key facts
Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.
| Field | Value |
|---|---|
| Repository | apache/solr |
| Owner | apache |
| Primary language | Java |
| License | Apache-2.0 — OSI-approved |
| Stars | 1.6k |
| Forks | 842 |
| Open issues | 167 |
| Latest release | Unknown |
| Last updated | 2026-07-07 |
| Source | https://github.com/apache/solr |
What solr is
Solr is a distributed search platform written in Java that leverages Lucene for indexing and querying. It provides REST APIs, supports multi-modal search (text, vector, spatial), and includes SolrCloud for distributed indexing and fault tolerance.
Get the solr source
Clone the repository and explore it locally.
git clone https://github.com/apache/solr.gitcd solr# follow the project's README for install & configurationNeed it deployed, integrated, or customized instead? DEV.co ships production installs.
Best use cases
Implementation considerations
- JVM heap sizing and garbage collection tuning are critical for query latency and stability; default configs require adjustment for production workloads.
- Schema design (field types, analyzers, copyFields) directly impacts search quality and must be planned before indexing large datasets.
- Distributed mode (SolrCloud) introduces operational complexity; single-node Solr is simpler but lacks fault tolerance and horizontal scaling.
- Reindexing strategy needed when schema changes are required; plan backup and alias-based rollover processes.
- Monitoring and alerting (metrics via JMX or HTTP APIs) are essential; native observability limited—integration with external systems (Prometheus, ELK) recommended.
When to avoid it — and what to weigh
- Simple Key-Value Lookups — Solr adds operational overhead for use cases better served by caching layers (Redis) or transactional databases. Not optimized for point lookups without search semantics.
- Real-Time Transactions — Solr is eventually consistent; document updates are indexed asynchronously. Avoid if you need ACID guarantees or immediate consistency across reads and writes.
- Lightweight, Embedded Scenarios — Solr is a server requiring JVM heap, separate process management, and operational tooling. Consider embedded alternatives (Lucene directly, SQLite FTS) for simple embedded use cases.
- Minimal Operations Capacity — SolrCloud cluster management, JVM tuning, and monitoring require DevOps expertise. Teams without search platform experience may find deployment and troubleshooting complex.
License & commercial use
Licensed under Apache License 2.0 (Apache-2.0), a permissive OSI-approved license granting rights to use, modify, and distribute.
Apache-2.0 permits commercial use without royalties or vendor lock-in. Attribution and license notice must be included. No vendor support or SLA included in open-source; commercial support available through ASF-affiliated consultants. Verify terms with legal counsel for mission-critical deployments.
DEV.co evaluation signals
Editorial assessment — not user reviews. Directional, with an explicit confidence level.
| Signal | Assessment |
|---|---|
| Maintenance | Active |
| Documentation | Strong |
| License clarity | Clear |
| Deployment complexity | High |
| DEV.co fit | Good |
| Assessment confidence | High |
No exploit details provided in data. Consider: default Solr installations have no authentication (open to LAN); production deployments must enable auth, network isolation, and TLS. JVM memory exposure (heap dumps), query injection via unsanitized input parameters. Run Solr on JDK with latest security patches. Refer to Solr security guide and Apache advisories before production deployment.
Alternatives to consider
Elasticsearch
Elastic-licensed, closed-source model; stronger out-of-box observability and automatic sharding. Steeper licensing costs at scale; consider if you need managed SaaS or prefer vendor ecosystem.
Meilisearch
Lightweight, simpler API, optimized for typo tolerance and relevance tuning. Lacks distributed mode and multi-modal search; better for greenfield projects with smaller scale needs.
OpenSearch
Open-source Elasticsearch fork (SSPL/Elastic License dual-licensed). Community-driven alternative if concerned about Elastic's licensing direction; API compatible with Elasticsearch.
Build on solr with DEV.co software developers
Let our search and cloud infrastructure experts guide your deployment. We'll assess schema design, SolrCloud topology, and operational readiness to ensure production stability.
Talk to DEV.coRelated open-source tools
Surfaced by semantic similarity across the DEV.co open-source index.
Related on DEV.co
Explore the category and the services that help you build with it.
solr FAQ
Do I need ZooKeeper for Solr?
How long does it take to index 1 billion documents?
Can Solr replace my primary database?
What JVM version should I use?
Work with a software development agency
Need help beyond evaluating solr? DEV.co is a software development agency offering software development services and web development for teams of every size. Our software developers and web developers build custom software, web applications, APIs, and open-source databases integrations — and maintain them long-term.
Ready to Deploy Solr?
Let our search and cloud infrastructure experts guide your deployment. We'll assess schema design, SolrCloud topology, and operational readiness to ensure production stability.