Open-Source Observability · microsoft

FASTER

FASTER is a Microsoft-backed, open-source persistent key-value store and log library designed for high-throughput applications that need to manage large state reliably. It offers both C# and C++ implementations, supports data larger than memory via external storage, and prioritizes performance and recovery resilience.

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Source: GitHub — github.com/microsoft/FASTER

6.6k

GitHub stars

595

Forks

Primary language

MIT

License (OSI-approved)

Key facts

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

Field	Value
Repository	microsoft/FASTER
Owner	microsoft
Primary language	C#
License	MIT — OSI-approved
Stars	6.6k
Forks	595
Open issues	37
Latest release	v2.6.5 (2024-05-07)
Last updated	2026-06-12
Source	https://github.com/microsoft/FASTER

What FASTER is

FASTER provides a concurrent, lock-free key-value store and high-performance persistent log with support for point lookups, heavy updates, fast checkpointing, and non-blocking recovery. It handles spillover to fast external storage and offers both synchronous and asynchronous interfaces with checksum validation and disk error handling.

Quickstart

Get the FASTER source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/microsoft/FASTER.git2cd FASTER3# follow the project's README for install & configuration

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

Best use cases

High-throughput stateful services requiring persistent recovery

Use FASTER when you need a fast, recoverable application state layer that can absorb millions of operations per second with frequent, low-latency commits and reliable crash recovery.

In-memory caches with hot-data overflow to SSD/cloud storage

FASTER's memory-aware design allows working datasets larger than RAM by automatically spilling to external storage, making it suitable for cache layers on memory-constrained infrastructure.

Distributed systems requiring consistent checkpointing without pauses

The non-blocking checkpointing technique is valuable for microservices and distributed systems that need consistent snapshots without stopping normal operations or sacrificing throughput.

Implementation considerations

FASTER requires careful tuning of memory allocation, hash table sizing, and spillover thresholds to achieve target performance; default configurations may not suit all workloads.
The C# and C++ implementations are separate codebases; feature parity and behavior consistency across languages should be verified for your use case.
Recovery and checkpointing logic is complex; thorough testing of failure scenarios and data corruption handling is essential before production deployment.
NuGet package (Microsoft.FASTER.Core) is available, but integration into existing systems requires understanding of FASTER's API surface, transaction model, and concurrency semantics.
External storage (local SSD, cloud blob) integration must be configured and tested; I/O performance characteristics directly impact application latency and throughput.

When to avoid it — and what to weigh

Simple key-value lookups with no durability requirement — FASTER's sophisticated persistence and concurrency model adds complexity. If you only need in-memory caching without recovery guarantees, simpler solutions like Redis or Memcached are more appropriate.
Range queries or complex secondary indexing — FASTER is optimized for point lookups and updates. Applications requiring range scans, full-text search, or complex queries should consider SQL or specialized NoSQL engines.
Small teams with limited C# or C++ expertise — FASTER requires skilled engineers comfortable with low-level concurrent programming, memory management, and persistent storage semantics. Operational complexity and tuning difficulty may exceed team capacity.
Cross-platform deployment without infrastructure lock-in preference — While FASTER supports Windows, Linux, and cloud, it is a stateful system requiring careful deployment planning. Vendor lock-in to Microsoft tools and frameworks may be a concern for some organizations.

License & commercial use

FASTER is licensed under the MIT License, a permissive open-source license. The MIT license permits commercial use, modification, and distribution with minimal restrictions, provided the original license and copyright notice are retained.

MIT license permits commercial use. However, verify with your legal team that inclusion of MIT-licensed code and attribution in your product meets internal compliance requirements. No warranty or indemnification is provided by the license; production use requires independent security and reliability assessment.

DEV.co evaluation signals

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

Signal	Assessment
Maintenance	Active
Documentation	Adequate
License clarity	Clear
Deployment complexity	High
DEV.co fit	Good
Assessment confidence	High

Security considerations

No security audit, threat model, or vulnerability history is provided in the data. Production deployment should include: independent security review of persistence and concurrency logic, verification of checksum and error-handling robustness, testing of recovery under malicious or corrupted input, and monitoring for resource exhaustion or denial-of-service via the API. Consult Microsoft security advisories and community feedback before relying on FASTER for security-sensitive applications.

Alternatives to consider

RocksDB (C++, Go bindings)

Embedded key-value store with widespread adoption, simpler operational model, and strong C++ performance; does not offer native C# or high-level caching abstractions.

Redis (C, with modules)

Mature in-memory data store with persistence options, simpler deployment, and broad ecosystem; not optimized for very large datasets or non-blocking checkpointing.

Apache Kafka (Java, Scala)

High-throughput persistent log with replication and stream processing; better for event streaming and distributed state than point-lookup key-value workloads.

Software development agency

Build on FASTER with DEV.co software developers

FASTER is a powerful but operationally complex library. Engage our team to assess fit, prototype integration, and plan deployment within your infrastructure and team constraints.

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FASTER FAQ

Can FASTER be used as a drop-in replacement for Redis?

No. While both are fast data stores, FASTER targets persistent, recoverable state for single applications with heavy updates; Redis is a networked cache with different semantics, replication, and deployment model. Porting requires code changes.

Does FASTER support distributed transactions or consensus?

No. FASTER is a single-node persistent store library. Multi-node consistency, replication, and consensus must be implemented by the application or external coordination layer.

What happens if external storage (SSD/cloud) fails or is unavailable?

Not clearly stated in provided data. Production deployment requires thorough review of failure handling, retry logic, and fallback behavior in FASTER documentation and source code.

Is there a managed service or cloud offering?

No. FASTER is an open-source library only. Applications must self-host, manage deployment, monitoring, and operational support independently.

Software developers & web developers for hire

DEV.co is a software development agency delivering custom software development services to companies building on open source. Our software developers and web developers design, integrate, and ship production systems — spanning web development, APIs, AI, data, and cloud. If FASTER is part of your open-source observability roadmap, our team can implement, customize, migrate, and maintain it.

Evaluate FASTER for Your Stateful Workload

FASTER is a powerful but operationally complex library. Engage our team to assess fit, prototype integration, and plan deployment within your infrastructure and team constraints.

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