Free AI Tools

Apache Cassandra stores time-series at petabyte scale. Write-heavy workload optimized. Time-bucketing for efficient queries. Replication across regions. Used by Apple and Netflix.

ClickHouse is columnar storage for analytic queries. 100B+ row tables analyzed in seconds. Compression 10x. Real-time ingestion. Time-series use case fully supported. Used by Yandex and Cloudflare.

Graphite stores time-series metrics and renders graphs. Whisper format for efficient storage. Carbonate proxy handles high ingestion. Graphite Render API for dashboarding. Mature, used at scale by many orgs.

Metricbeat from Elastic ships metrics to Elasticsearch. Modules for common services (Docker, Postgres, Redis). Lightweight agent. Integrates with Kibana visualizations. Part of Elastic Stack.

Netdata collects 1000+ metrics per second per node. Single daemon with no dependencies. Distributed parent-child architecture. ML detects anomalies. Visualize and alert in web UI. Open-source and enterprise options.

OpenTSDB stores time-series on top of HBase. Billions of metrics at millisecond precision. Tag-based queries. Built-in aggregators for rollups. Java-based backend.

Prometheus Remote Write sends time-series to external backends. Write to remote_write for long-term storage. Read from remote_read for queries. Supported by Mimir, Thanos, Cortex. Scale Prometheus horizontally.

StatsD is a lightweight protocol and reference implementation for publishing application metrics. Applications send counters, timers, and gauge values via UDP packets to a local agent. The agent aggregates metrics at intervals and exports to backend time-series databases. Graphite and Prometheus scrapers consume StatsD output. This widely adopted standard powers monitoring across millions of applications globally.

Telegraf is a plugin-driven server agent for collecting metrics. 200+ input plugins (CPU, disk, Docker, Prometheus). Output to InfluxDB, Graphite, or Kafka. Lightweight, single binary. Standard in monitoring stacks.

Thanos is a set of components extending Prometheus. Sidecar uploads blocks to S3. Querier aggregates across all Prometheus instances. 5-year retention. Ruler for alert generation. CNCF project.

Spotify's Annoy library indexes high-dimensional vectors in memory. Fast search and low memory usage. Python and C++ implementations. Used internally by Spotify. Active maintenance.

EmbedWell Store adds pgvector to open-source Postgres. Serverless PostgreSQL with vector support. Hosted or self-hosted. Edge function integration with LLMs. Fast setup.

MongoDB provides SDKs for vector embeddings. Integrates with OpenAI embeddings. Python and JS support. Simplified development. Part of Atlas ecosystem.

NMSLIB provides approximate nearest neighbor search. C++, Python, Java, Ruby bindings. HNSW and other algorithms. High performance tuning options. Research origins.

pgvector is an open-source extension for Postgres. Store and search vectors in Postgres. Index types: IVF, HNSW. No separate database needed. Simple to deploy. Community-maintained.

Vald is an open-source distributed vector database. High-dimensional approximate nearest neighbor search. Horizontally scalable. Python and Go clients. Japanese origin, growing adoption.

GraphX is Spark's graph processing library. Parallelize graph algorithms across clusters. Pregel abstraction for iterative computation. Works with Parquet and other Spark sources. Free to use. Scales to petabyte graphs.

Blazegraph is an RDF database supporting SPARQL queries. Named graphs for data organization. Inference over OWL ontologies. Full-text indexing. Open-source origins, now maintained by Blazegraph team.

Cayley is an open-source graph database written in Go. Support for RDF quads. Gizmo query language. Multiple backends: memory, LevelDB, SQL. Designed for large semantic datasets. Google-backed origins.

Cypher is a declarative query language for property graphs. Pattern matching syntax. Create, read, update, delete operations. JOINs via relationships. Standard adopted by TigerGraph and Memgraph.