nats-io/nats-server

Features

• Distributed Messaging - Implements a scalable, resilient messaging backbone supporting publish-subscribe, request-reply, and load-balanced queue patterns.
• Publish-Subscribe Messaging - Provides a high-performance publish-subscribe messaging backbone for decoupled communication between distributed services.
• Distributed Key-Value Stores - Integrates a replicated, atomic storage engine for managing configuration and state across distributed services.
• Subject Subscription Filtering - Routes messages using hierarchical subject matching to enable decoupled publish-subscribe communication.
• Message Queues - Functions as a cloud-native messaging infrastructure supporting persistent streams and load-balanced work queues.
• Messaging Services - Runs a server process that listens for client connections to facilitate communication between distributed services.
• Client-to-Client Messaging - Enables decoupled, asynchronous communication between services using publish-subscribe and request-reply patterns.
• Message Brokers - Provides a high-performance, lightweight messaging broker for asynchronous communication and decoupled service interaction using subject-based routing.
• Multi-tenant Security - Implements decentralized security through isolated accounts and shared resources, allowing fine-grained control over user permissions and connection restrictions.
• Decentralized Token Authorization - Validates client identity and permissions using decentralized, cryptographically signed tokens.
• Durable Event Logs - Provides log-structured stream persistence for reliable message replay and durable delivery.
• Distributed Key-Value Stores - Provides an atomic, replicated key-value store integrated into the messaging layer for distributed state management.
• Persistent Storage Providers - Provides a high-performance storage layer for stream persistence, message replay, and reliable delivery.
• Reliable Event Delivery Systems - Supports persistent event streaming with configurable retention policies for reliable delivery and state recovery.
• Message Brokers - Facilitates asynchronous data exchange between distributed services using publish-subscribe and request-reply patterns.
• Cluster Discovery Mechanisms - Maintains a self-healing mesh network using gossip-based discovery for automated cluster membership.
• Message Stream Handlers - Capture and store messages published to specific subjects using configurable retention policies and cluster-level placement.
• Message Stream Replayers - Store published messages in a distributed engine to allow consumers to retrieve historical data or replay streams on demand.
• Connection Authentication Mechanisms - Validates incoming client identities using methods including tokens, passwords, TLS certificates, and NKEYs.
• Identity and Access Management - Configures operators, accounts, and users with granular permissions for secure messaging interactions.
• Access Control and Authorization - Enforces granular access control by embedding publication and subscription restrictions directly into user tokens for decentralized management.
• Mutual TLS Authentication - Validates client identity using multiple methods including TLS, NKEYS, credentials, tokens, or standard password pairs.
• JWT Identity Management - Uses decentralized JSON Web Tokens to define permissions and identity without storing private keys on the server.
• JWT Authentication - Validates client identity and permissions using decentralized JSON Web Tokens managed by an external authority or local resolver.
• Multi-Tenancy Security - Isolates messaging traffic into independent accounts with separate subject namespaces and controlled cross-account communication.
• Messaging Isolation Fabrics - Enforces multi-tenant security by isolating messaging traffic into independent accounts with granular access control and controlled cross-account data sharing.
• Multi-Tenant Security - Segregates messaging traffic into independent accounts with granular access control for multi-tenant isolation.
• Peer Communication Security - Enforces mutual TLS authentication for all inter-server connections to ensure only verified nodes can join or communicate within a cluster.
• Subject Access Restrictions - Controls client ability to publish or subscribe to specific message subjects using allow and deny lists and wildcard patterns.
• Distributed Key-Value Stores - Provides an atomic, replicated key-value store for managing configuration or state across microservices and edge deployments.
• Hierarchical Subject Organization - Organizes communication channels into dot-separated namespaces to simplify security and filtering policies.
• Patterns - Implements bidirectional request-reply communication by dynamically routing responses back to the original requester.
• Data Persistence - Store message sequences to enable temporal decoupling, allowing subscribers to replay historical data or consume messages as a work queue.
• Data Streaming - Creates, updates, deletes, and purges message streams to organize and persist data within the messaging infrastructure.
• Data Replication - Synchronizes message streams and consumer states across multiple server nodes using consensus groups to ensure high availability.
• Atomic Key-Value Operations - Executes conditional updates on stored values to enable distributed locking and concurrency control across multiple clients.
• Messaging Throughput Scaling - Adjusts CPU and memory allocations to match message volume, network bandwidth, and persistence requirements for both standard messaging and persistent stream storage.
• Replication Protocols - Distributes stream data across multiple cluster nodes using consensus protocols to ensure high availability and fault tolerance.
• Configuration Hot-Reloading - Updates server settings without requiring a restart or disconnecting active clients via process signals.
• Cluster Bridging - Links geographically distributed clusters using gateways to enable disaster recovery and location-aware message processing.
• Deployment Scaling - Provides flexible deployment configurations ranging from single-process edge instances to globally distributed superclusters.
• Graceful Shutdowns - Provides a maintenance mode that rejects new connections and drains existing ones before stopping the server process.
• High Availability Clusters - Maintains high availability through self-healing clusters, leaf nodes, and superclusters for flexible deployment.
• Queue-Based Message Distribution - Enables horizontal load balancing by grouping subscribers so each message is delivered to only one member of the group.
• Zero-Downtime Deployments - Applies changes to server settings and credentials without downtime by signaling the running process.
• Global Messaging Fabrics - Joins multiple independent clusters into a global messaging fabric for seamless cross-cluster communication.
• Service Discovery - Exposes discoverable services by grouping operations into versioned endpoints for distributed interaction.
• Messaging Client Connections - Provides flexible client connectivity using standard protocols, TLS, and WebSockets for distributed service communication.
• Cross-Account Replication - Enables secure cross-account data sharing through explicit import and export definitions with activation token support.
• Distributed State Management - Provides key-value stores with versioning and time-to-live settings for sharing state between services.
• Load Balancers - Distributes incoming requests across dynamic groups of responders to scale processing capacity.
• Message Delivery Guarantees - Provides configurable acknowledgment modes to ensure reliable message delivery and processing confirmation.
• Multi-Cluster Connectivity Fabrics - Links multiple independent messaging clusters into a unified mesh for cross-cluster communication and optimized routing.
• Multi-Cluster Service Connectivity - Configures client connections with multiple server addresses and secure transport protocols for high availability.
• Publish-Subscribe Systems - Supports hierarchical subject-based routing with wildcard pattern matching for flexible message subscription.
• Edge Proxies - Extends messaging backbones to isolated environments by tunneling traffic through persistent edge connections.
• Authentication Clients - Validates incoming client connections using username and password credentials.
• Challenge-Response Authenticators - Verifies client identity using a challenge-response mechanism where the client signs a server-provided nonce.
• Credential Authentication - Enforces password-based access control for incoming connections to ensure only authorized clients can interact with the messaging server.
• Request Access Restrictions - Enforces connection security by requiring clients to provide valid credentials before interacting with the messaging system.
• Encrypted Connection Handlers - Secures communication between clients and the server by enforcing TLS encryption with configurable cipher suites and protocol versions.
• Identity Hierarchies - Implements hierarchical trust chains using public-key signatures to define operators, accounts, and users with specific access limits.
• Remote Service Authentication - Validates incoming and outgoing server connections using credentials, Nkeys, or JWT-based signatures to ensure only authorized nodes join the network.
• Secure Connection Managers - Establishes authenticated and encrypted persistent channels for secure data exchange.
• Secure Network Communication - Secures communication between clients and servers using TLS to prevent eavesdropping and verify server identity.
• TLS Transfer Security - Provides TLS-based encryption for network traffic to prevent unauthorized access and ensure secure communication.
• Token Authentication - Validates client identities using digitally signed JSON Web Tokens that establish a chain of trust without requiring server-side configuration changes.
• Zero Trust Access Controls - Authenticates and authorizes all connections using TLS and JSON Web Tokens to ensure secure distributed communication.
• Distributed Storage Clusters - Connects multiple server instances into a unified network to share message traffic and provide horizontal scalability across different nodes.
• Distributed Task Queues - Balances message processing across multiple service instances using named queue groups.
• Messaging Patterns - Facilitates bidirectional request-reply communication patterns by dynamically routing responses to specific reply subjects.
• Remote Service Invocations - Facilitates transparent remote service calls using message-based request-reply patterns.
• Cluster Monitoring - Provides real-time dashboards and metrics for tracking cluster health and resource utilization across the messaging fabric.
• Server Metrics - Provides HTTP endpoints returning real-time statistics on server health, connections, and message persistence.
• Observability Tracing - Generates and aggregates diagnostic events across system boundaries to monitor message flow and subsystem interactions.
• Caching and Messaging - High-performance cloud-native messaging system.
• Message Queues - Cloud-native messaging middleware.
• Messaging and RPC - A cloud-native messaging middleware.
• Messaging Systems - High-performance messaging system for cloud-native apps.
• Distributed Systems - Communications system for digital services.
• Connection Establishment - Establishes persistent connections between distributed services to exchange data using various messaging patterns.
• Data Persistence and Storage - Stores messages in memory or on disk, enabling durable subscriptions and the ability to replay historical data.
• Exactly-Once Processing Semantics - Combines message deduplication with synchronous acknowledgment verification to ensure messages are processed exactly once without loss or duplication.
• Subscription Interest Synchronization - Communicates interest in specific subjects across servers to ensure messages are routed only to nodes with active subscribers.
• Message Storage - Stores incoming messages on disk to ensure data durability and allow for later retrieval by consumers.
• Namespace Isolation - Segregates message traffic into independent accounts to prevent unauthorized cross-account access.
• Primary-Replica Replication - Automatically maintains stream replication factors by replacing failed replicas within a cluster.
• Messaging Infrastructure - Automates the deployment and configuration of messaging servers within continuous integration pipelines.
• Connection Reconnection Policies - Implements automatic reconnection logic and error recovery to maintain persistent communication channels between clients and server clusters.
• Connection Establishment Protocols - Supports robust network connection establishment across TCP, TLS, and WebSockets with built-in cluster discovery.
• Connection Management - Automatically restores network links and re-establishes subscriptions after a disconnection, allowing applications to self-heal without manual intervention or additional configuration.
• Client Connection Distribution - Balances traffic across cluster nodes using built-in discovery to maintain high throughput without external load balancers.
• At-Most-Once Delivery - Provides fire-and-forget message delivery for high-performance, non-persistent communication.
• Message Subscription Management - Controls data flow by managing client interest in specific message subjects.
• Message Delivery Guarantees - Configures stream delivery policies to support historical replay, sequence resumption, or real-time delivery.
• Message Ordering Guarantees - Ensures sequential, gap-free message processing for consumers, automatically handling reconnections while maintaining strict order.
• Context Isolation Strategies - Organizes communication into distinct accounts to ensure message isolation between contexts.
• Client Certificate Authentication - Validates client identity by verifying certificates against a trusted certificate authority or mapping attributes to user identities.
• Client Certificate Management - Requires and validates client certificates during the TLS handshake to verify identity, optionally mapping certificate values to specific user accounts.
• Client Credentials - Validates incoming connections against a defined list of usernames and passwords to ensure authorized access.
• Data Encryption - Protects persistent message data stored on disk by applying encryption to ensure information remains secure.
• Environment Isolation - Creates logically separated storage domains to ensure resource isolation within shared messaging infrastructure.
• Key-Scoped Permissions - Associates specific access permissions with a signing key so that any user signed by that key inherits those restrictions.
• Digital Signature Validators - Validates client identity by requiring a digital signature of a server-generated challenge.
• Stream Access Restrictions - Limits access to specific data streams by requiring authorization tokens, ensuring only designated accounts can import private resources.
• Credential Revocation - Invalidates specific user sessions, activation tokens, or entire accounts by updating revocation lists or removing signing keys.
• Messaging Session Persistence - Maintain session state and message delivery status across reconnections, ensuring reliable communication even if the network is interrupted.
• Identity and Access Management - Generates and manages cryptographic keys and authentication tokens to define user permissions and access control policies.
• Security Isolation Mechanisms - Creates secure, isolated messaging contexts to maintain data silos across multiple tenants.
• Service Communication Security - Enforces mutual authentication and encrypted transit between messaging nodes using TLS and certificate-based validation.
• User Account Management - Restricts user access to specific message subjects by defining granular publish and subscribe permissions for individual accounts and users.
• Asynchronous Messaging - Implements non-blocking, event-driven message reception via callback handlers for efficient processing.
• Distributed Coordination Systems - Automates cluster coordination by enabling nodes to discover peers and establish consensus groups upon joining.
• Service Access Restrictions - Limits access to private services by requiring activation tokens that grant specific accounts permission to interact with the service.
• Health Monitoring Endpoints - Exposes standardized HTTP endpoints for reporting real-time server health and operational status.
• Prometheus Exporters - Translates internal server performance data into Prometheus-compatible formats for long-term storage.
• Account Resource Monitoring - Tracks current memory and storage consumption against defined limits to ensure multi-tenant environments remain within allocated quotas.
• Multi-Protocol Clients - Accepts connections from diverse clients using native protocols, MQTT, and WebSockets.
• Consumer Offset Trackers - Maintains durable message tracking across server restarts or uses ephemeral consumers for transient, auto-cleaning message views.
• Data Change Subscriptions - Provides real-time subscription mechanisms to trigger actions whenever specific key-value data is modified.
• Message Deduplication - Prevents duplicate data ingestion by tracking unique message identifiers within configurable time windows.
• Retention Policies - Configures message persistence limits based on age, size, or count to manage data retention.
• Pull Consumer Scalers - Enables horizontal scaling of message processing through demand-driven pull consumers.
• Cluster Node Management - Automates the eviction of unresponsive cluster peers to maintain data redundancy and cluster health.
• Distributed Task Queues - Scales work queues by distributing message processing across multiple horizontal pull-based workers.
• Resource Quotas - Limits memory and disk storage capacity for specific accounts to ensure predictable performance.
• Service Health Monitoring - Provides automated responses for service discovery and metadata queries to monitor operational health.
• Resource Controllers - Enables defining and maintaining message streams using standard Kubernetes cluster resource definitions.
• Messaging Servers - Connects multiple messaging server instances to share state and distribute traffic.
• Delivery Patterns - Supports both server-initiated push and client-requested pull delivery for flexible throughput management.
• Request Routing - Prioritizes local service delivery within a cluster and only routes requests to remote regions when no local listeners are available to handle the traffic.
• Rolling Update Orchestrators - Updates clusters by cycling through nodes one at a time using graceful shutdown to ensure service continuity.
• Cluster Discovery Services - Identifies active servers within a cluster through automated discovery requests.
• Real-Time Data Streams - Forwards incoming stream messages to a secondary destination subject in real-time to support high-scale consumption.
• Flow Control Mechanisms - Regulates message throughput using acknowledgment windows and pending message limits to prevent client overload.
• Message Broker Consumers - Defines retrieval rules for message consumers, including delivery modes, filtering, and acknowledgment policies.
• Consumer Group Coordinators - Balances message processing workloads by distributing streams across multiple consumer instances.
• Slow Consumer Eviction - Protects system stability by terminating connections to subscribers that cannot keep up with message processing rates.
• Message Queue Clients - Limits which queue groups a client can join or subscribe to, allowing granular control over load-balanced message consumption.
• Message Scheduling - Supports delayed message delivery and recurring tasks using cron-style scheduling expressions.
• Message Stream Orchestration - Manages data persistence and consumer delivery states to ensure reliable message processing.
• Message Integrity Controls - Applies deduplication and concurrency controls to published messages to ensure data consistency and prevent duplicate processing.
• Network Topology Extensions - Connects remote messaging servers to a central hub to aggregate traffic and extend service reach.
• Topology Abstraction Layers - Decouples applications from network changes by automatically updating client connections when server deployments evolve.
• Real-Time Messaging Systems - Retrieves historical and real-time messages from streams using flexible delivery policies.
• Guest Access Mappers - Maps clients connecting without credentials to a specific user identity within a designated account.
• Account Management - Delegates account administration to external entities using trust chains for decentralized resource management.
• Authentication Services - Offloads client identity verification and permission checks to an external application-defined service, allowing integration with existing identity providers.
• Hybrid Authentication Providers - Supports simultaneous use of static key-based credentials and decentralized token-based identity systems.
• Dynamic Permission Templates - Generates unique, user-specific subject permissions using dynamic placeholders within scoped signing keys.
• Service Access Revocation - Invalidates specific account access to shared exports at a defined time, ensuring previous authorization tokens are no longer accepted.
• Identity & Key Management - Generates public and private key pairs to establish secure, verifiable identities for messaging clients.
• Identity Management - Manages account identities and authorization tokens locally within server configuration files.
• Leaf Node Traffic Restrictions - Limits message flow between local and remote systems by applying authorization policies to leaf node connections.
• User Access Revocation - Invalidates existing user credentials based on a specific timestamp, requiring new credentials for continued access.
• WebSocket Security - Validates incoming WebSocket connections using various security methods including tokens, certificates, and identity-based credentials.
• Response Permission Controllers - Configures response limits and temporary access rules to secure dynamic reply subjects in request-reply exchanges.
• Subject Namespace Mapping - Redirects incoming messages from one subject to another, allowing for namespace migrations or subject reordering using wildcard token references.
• Message Header Attachments - Includes custom header fields and optional reply addresses within message payloads to support complex routing.
• Subscription Callback Handlers - Routes incoming messages to application logic by mapping subscription identifiers to handler functions.
• Cluster Health Monitoring - Queries performance metrics and cluster health statistics using request-reply patterns.
• Graceful Shutdown Mechanisms - Provides lifecycle controls for graceful shutdowns, configuration reloads, and log rotation.
• Account Statistics Monitoring - Retrieves real-time metrics and usage limits for accounts to ensure operational visibility and capacity planning.
• Connection Throughput Trackers - Reports metrics on data throughput including the total count of messages sent and received by a client.
• Link Health Maintenance - Uses periodic heartbeat signals to verify the status of inter-server links and automatically disconnect unresponsive nodes.
• Stream Status Monitors - Retrieves health information and usage statistics for streams and consumers to maintain system visibility.
• Traffic Monitoring Tools - Streams message traffic to external observers for auditing and observability without impacting primary processing.
• Responder Availability Notifications - Sends an immediate signal to a client when no subscribers are available to process a request, preventing applications from hanging on blocked calls.
• Data Storage - Deletes individual messages or clears stored data within a stream to manage storage capacity and lifecycle requirements.
• Streaming Data Processing - Supports push and pull patterns for consuming persistent log data at scale.
• Stream Processing - Interleaves multiple data streams with support for subject-based transformations and filtering.
• Data Retention Policies - Configures stream limits based on age, size, or count, with automated discard policies to manage storage capacity.
• Stream Snapshotters - Facilitates data durability and disaster recovery by creating point-in-time snapshots of stream configurations and payloads.
• Key-Value Pair Managers - Provides isolated storage containers for key-value pairs to manage data sets independently.
• Atomic Key Updaters - Supports atomic, conditional updates to key-value data to ensure consistency during state changes.
• Binary Object Chunkers - Manages large binary objects by automatically chunking data for efficient storage and retrieval.
• Storage Configuration - Defines persistent storage containers that specify captured subjects and data retention policies.
• Stream Filters - Applies server-side subject matching to deliver only relevant subsets of messages to specific consumers, reducing unnecessary network traffic.
• Stream Lifecycle Management - Provides administrative controls to purge, delete, or inspect stored message data and consumer configurations.
• Server Lifecycle Managers - Supports process signaling for shutdowns, configuration reloads, and log file rotation during runtime.
• Connection Termination - Ensures data integrity during shutdown by processing all pending and inflight messages before closing connections.
• Infrastructure Provisioning Tools - Automates the lifecycle management of messaging streams and consumers using infrastructure-as-code patterns.
• Distributed Infrastructure - Connects separate messaging environments across cloud and edge systems to create a unified communication fabric.
• Infrastructure as Code - Automates the deployment of messaging resources using declarative files for consistent environment configuration.
• Platform as a Service - Operates a messaging server as a single process, fault-tolerant cluster, or globally distributed super-cluster.
• Synchronous Message Receivers - Allows blocking the execution thread to wait for and retrieve incoming messages from a specific subject.
• Retained Messages - Stores messages with a retain flag to ensure new subscribers receive the most recent state.
• Throughput Benchmarking - Measures message delivery rates and latency for publishers and subscribers by simulating various client counts and message sizes.
• Data Streaming - Configures and maintains data streams with support for backup and restoration tasks.
• Data Synchronization and Consistency - Mirrors data between streams using automated retries and heartbeats to maintain consistency across distributed environments.
• Domain Identifiers - Allows assigning unique domain names to server groups to create independent namespaces and disambiguate API requests.
• Ephemeral Consumers - Creates short-lived consumers that persist only while active and are removed once all subscriptions are closed.
• Stream Message Fetchers - Supports granular retrieval of stored stream messages by sequence number or bulk snapshot operations.
• Messaging Integrations - Connects to external message brokers and event streaming platforms to synchronize data flows.
• Messaging Systems - Rewrites message subjects dynamically as they enter the system to support namespace translation and compatibility.
• Network Data Compression - Reduces bandwidth usage between connected servers by applying compression algorithms to messaging streams and WebSocket frames.
• Network Connectivity Configurations - Defines host, port, and protocol settings for client connections, including support for TLS, WebSockets, and MQTT.
• Connection Lifecycle Managers - Manages automated state transitions and reconnection logic for persistent network connections.
• Scatter-Gather Patterns - Supports scatter-gather patterns by broadcasting requests to multiple subscribers and collecting responses within a time window.
• Account Claim Resolvers - Configures how the server retrieves and updates account information using static memory, remote HTTP, or dynamic lookups.
• Account Synchronization - Synchronizes account credentials with external operators to ensure consistent access control across distributed environments.
• Traffic Isolation - Assigns dedicated network routes to specific accounts to reduce latency and minimize protocol overhead by removing account identifiers from transmitted message headers.
• Authorization Services - Delegates authentication and authorization decisions to external services via real-time callouts.
• Credential File Parsers - Verifies client identity using a local file containing a JSON Web Token and a private NKey to establish secure connections.
• Account Identity Resolvers - Configures how the server retrieves and validates account information using local memory, messaging-based lookups, or external services.
• Storage Encryption - Protects persistent message data by applying encryption to ensure information remains secure even if the underlying storage is compromised.
• Account Configuration Syncing - Automates the distribution of account and user definitions to messaging servers via centralized resolution.
• Propagation Filters - Filters traffic across network links by explicitly denying the import or export of specific subjects to control data visibility and flow.
• Key History Trackers - Allows auditing and state reconstruction by retrieving historical value sequences for specific keys.
• Connection Lifecycle - Exposes lifecycle hooks to monitor connection status changes and handle asynchronous runtime errors.
• Dead Letter Queues - Tracks failed delivery attempts to route problematic data to specialized handlers for inspection or recovery.
• Stream Replicators - Provides automated asynchronous replication of message streams to support geographic distribution and data aggregation.
• Automated Server Maintenance - Streamlines server administration and configuration updates through a command-line interface.
• Event Monitoring Systems - Broadcasts operational events to dedicated subjects, enabling real-time analysis of infrastructure activity.
• Request-Reply - Evaluates the round-trip time and throughput of synchronous request-reply interactions between service instances.
• Distributed Tracing - Captures and exports message metadata using open telemetry standards to monitor distributed request paths.
• Resource Usage Limiters - Caps system usage by restricting connection counts, message payload sizes, subscription limits, and memory buffers to protect server stability.
• Session Health Monitors - Pings connected clients periodically and disconnects those that fail to respond within a defined timeframe to prune inactive sessions.
• System Event Monitors - Broadcasts server-side lifecycle and activity notifications to dedicated subjects for infrastructure tracking.
• Endpoint Specification - Exposes specific operations as individual endpoints to handle incoming requests from clients.

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