Changelog

version 0.3.1 (2025.07.17)

LeaderWorker Registration Fix

Problem Resolution

  • Fixed LeaderWorker registration warnings: Resolved warning messages "LeaderWorker registration issue: expected #PID<...>, got nil"
  • Store-specific registration verification: LeaderWorker now properly verifies its registration using the store-specific name instead of the hardcoded module name
  • Improved logging: Registration confirmation logs now show the actual store-specific process name

Technical Implementation

  • Updated init/1 function: LeaderWorker now extracts store_id from config and uses StoreNaming.genserver_name/2 to determine the expected registration name
  • Correct registration check: Uses Process.whereis(expected_name) instead of Process.whereis(__MODULE__) for verification
  • Enhanced logging: Log messages now show the actual store-specific name used for registration

Benefits

  • Cleaner logs: Eliminates confusing registration warning messages during startup
  • Better debugging: Registration verification now works correctly with store-specific naming
  • Improved reliability: Proper registration verification helps identify actual process registration issues

version 0.3.0 (2025.07.17)

Multiple Stores Naming Conflicts Fix

Problem Resolution

  • Fixed naming conflicts: Resolved already started errors when multiple umbrella applications attempted to start their own ExESDB systems
  • Store isolation: Each store now has its own isolated set of partition supervisors
  • Multi-tenancy support: Different applications can maintain completely separate event stores within the same Elixir node

Updated Components

  • ExESDB.Emitters: Updated start_emitter_pool/3 to use store-specific partition names
  • ExESDB.EmitterSystem: Updated supervisor child spec to use store-specific partition names
  • ExESDB.GatewaySystem: Updated supervisor child spec to use store-specific partition names
  • ExESDB.LeaderWorker: Updated process lookup to use store-specific partition names
  • ExESDB.Snapshots: Updated supervisor child specs to use store-specific partition names
  • ExESDB.SnapshotsReader: Updated start_child/2 to use store-specific partition names
  • ExESDB.SnapshotsWriter: Updated start_child/2 to use store-specific partition names
  • ExESDB.Streams: Updated supervisor child specs to use store-specific partition names
  • ExESDB.StreamsReader: Updated start_child/2 to use store-specific partition names
  • ExESDB.StreamsWriter: Updated start_child/2 to use store-specific partition names

Technical Implementation

  • Store-specific naming: All modules now use ExESDB.StoreNaming.partition_name/2 to generate unique process names
  • Unique process names: Each store gets its own partition supervisors (e.g., :exesdb_streamswriters_store_one, :exesdb_streamswriters_store_two)
  • Backward compatibility: Existing single-store deployments continue to work unchanged
  • Consistent pattern: All partition supervisors follow the same naming convention

Affected Processes

  • ExESDB.StreamsWriters: Now store-specific to prevent conflicts
  • ExESDB.StreamsReaders: Now store-specific to prevent conflicts
  • ExESDB.SnapshotsWriters: Now store-specific to prevent conflicts
  • ExESDB.SnapshotsReaders: Now store-specific to prevent conflicts
  • ExESDB.EmitterPools: Now store-specific to prevent conflicts
  • ExESDB.GatewayWorkers: Now store-specific to prevent conflicts

Benefits

  • True multi-tenancy: Multiple applications can run separate ExESDB systems without conflicts
  • Better isolation: Each store operates independently with its own resources
  • Improved reliability: Eliminates startup failures due to naming conflicts
  • Enhanced scalability: Supports complex umbrella application architectures
  • Maintained compatibility: Zero breaking changes for existing deployments

version 0.1.7 (2025.07.16)

Configuration System Modernization

Legacy Configuration Removal

  • Removed khepri configuration: Eliminated legacy config :ex_esdb, :khepri configuration format
  • Modernized Options module: Updated ExESDB.Options to use umbrella-aware configuration patterns
  • Consistent configuration format: All configurations now use config :your_app_name, :ex_esdb, [options] format
  • Improved isolation: Better configuration isolation between applications in umbrella projects

Configuration Documentation

  • New configuration guide: Added comprehensive guides/configuring_exesdb_apps.md guide
  • Standalone application examples: Complete configuration examples for single-app deployments
  • Umbrella application examples: Detailed examples for multi-app umbrella projects
  • Environment variable documentation: Complete reference for all environment variable overrides
  • Migration guide: Instructions for migrating from legacy khepri configuration

Configuration Features

  • Context management: Enhanced context switching for umbrella applications
  • Explicit context support: Added app_env/3 functions for explicit context usage
  • Context wrapper support: Added with_context/2 for scoped configuration access
  • Libcluster integration: Emphasized libcluster usage over deprecated seed_nodes mechanism

Benefits

  • Better umbrella support: Proper configuration isolation for umbrella applications
  • Clearer configuration patterns: Consistent config :app_name, :ex_esdb format
  • Improved developer experience: Comprehensive documentation and examples
  • Enhanced maintainability: Removed legacy code paths and simplified configuration logic

version 0.1.2 (2025.07.14)

Store Configuration Enhancement

New Environment Variables

  • EX_ESDB_STORE_DESCRIPTION: Human-readable description of the store for documentation and operational purposes
  • EX_ESDB_STORE_TAGS: Comma-separated tags for store categorization and filtering (e.g., "production,cluster,core")

Rich Store Configuration

  • Operational Metadata: Added created_at, version, and status fields to store configuration
  • Resource Management: Added priority and auto_start fields for resource allocation control
  • Administrative Info: Enhanced store registry with tags, environment, and description fields
  • Enhanced Querying: Store registry now supports filtering by tags, environment, priority, and other metadata

Configuration Integration

  • Runtime Configuration: New environment variables integrated into config/runtime.exs
  • Options System: Added parsers in ExESDB.Options with comma-separated tag parsing
  • Store Registry: Enhanced build_store_config/1 to include all new metadata fields
  • Development Environment: Updated dev-env/*.yaml files with new environment variables

Architectural Refactoring

NotificationSystem Introduction

  • New Core Component: Created ExESDB.NotificationSystem as a core supervisor for event notification
  • Leadership Integration: Moved LeaderSystem from clustering layer to core system
  • Core System Enhancement: Updated CoreSystem to include NotificationSystem alongside PersistenceSystem and StoreSystem
  • Supervision Order: PersistenceSystem → NotificationSystem → StoreSystem for proper dependency management

LeaderWorker Availability Fix

  • Core System Integration: LeaderWorker now starts as part of core system, not clustering components
  • Startup Order: LeaderWorker is available before clustering components attempt to use it
  • Resolved :noproc Error: Fixed LeaderWorker activation failures by ensuring it's always running when needed
  • Single and Cluster Mode: LeaderWorker now available in both single-node and cluster modes

System Architecture Cleanup

  • Removed LeadershipSystem: Consolidated functionality into NotificationSystem
  • Cleaner Separation: Core functionality (leadership, events) vs clustering (coordination, membership)
  • Improved Documentation: Updated supervision tree documentation to reflect new architecture
  • Simplified Dependencies: Reduced coupling between core and clustering components

Process Management Enhancement

Graceful Shutdown Implementation

  • Universal Coverage: All 18 GenServer processes now implement graceful shutdown
  • Terminate Callbacks: Added terminate/2 callbacks to all GenServers for proper cleanup
  • Exit Trapping: Enabled Process.flag(:trap_exit, true) on all GenServers
  • Resource Cleanup: Proper cleanup of Swarm registrations, PubSub subscriptions, and Khepri stores

Enhanced Process Lifecycle

  • Swarm Registration Cleanup: Worker processes properly unregister from Swarm on shutdown
  • PubSub Subscription Cleanup: EventProjector properly unsubscribes from topics
  • Khepri Store Shutdown: Store processes gracefully stop Khepri instances
  • Network Monitoring: NodeMonitor properly disables network monitoring on shutdown

Development Environment

Configuration Updates

  • proc-sup Configuration: Added description "Process Supervisor Event Store" and tags "development,cluster,proc-sup,core"
  • reg-gh Configuration: Added description "Registration System Event Store" and tags "development,cluster,reg-gh,registration"
  • Environment-Specific Tags: Different tags for development vs production environments
  • Consistent Formatting: Standardized environment variable layout across all configuration files

Benefits

Operational Improvements

  • Enhanced Monitoring: Rich store metadata enables better operational visibility
  • Improved Debugging: Store descriptions and tags help identify issues faster
  • Better Resource Management: Priority and auto-start fields enable fine-grained control
  • Cleaner Shutdown: All processes terminate gracefully without resource leaks

Development Experience

  • Clearer Architecture: Separation of core vs clustering concerns
  • Consistent Configuration: Standardized environment variable management
  • Better Testability: Core components can be tested independently of clustering
  • Simplified Debugging: LeaderWorker availability issues resolved

System Reliability

  • Reduced Race Conditions: Proper startup order prevents timing-related failures
  • Resource Leak Prevention: Graceful shutdown prevents resource accumulation
  • Improved Fault Tolerance: Better separation of concerns reduces cascade failures
  • Enhanced Observability: Rich metadata supports better monitoring and alerting

version 0.1.1 (2025.07.13)

StoreRegistry Refactoring

Enhanced Architecture

  • Store Registration Centralization: Moved store registration functionality from StoreCluster to dedicated StoreRegistry module
  • Self-Registration: StoreRegistry now automatically registers its own store during initialization when store_id is provided
  • Simplified StoreCluster: StoreCluster now focuses purely on cluster coordination without store registration concerns

API Integration

  • ExESDBGater.API Integration: list_stores() function now directly calls ExESDB.StoreRegistry.list_stores() instead of maintaining local state
  • Single Source of Truth: Store information is now centralized in StoreRegistry across the entire system
  • Improved Error Handling: Added proper error handling for StoreRegistry calls in GaterAPI

System Integration

  • StoreSystem Supervision: Added StoreRegistry to the StoreSystem supervisor with proper startup order
  • Component Isolation: Each component now has a single, well-defined responsibility
  • Cleaner State Management: Removed redundant store state from multiple components

Benefits

  • Separation of Concerns: Clear boundaries between clustering and registration responsibilities
  • Maintainability: Easier to maintain and reason about store registration logic
  • Testability: Store registration can now be tested in isolation
  • Reduced Coupling: Components are less tightly coupled and more modular

version 0.0.17 (2025.07.01)

Auto-Clustering

  • ExESDB nodes now automatically join the cluster
  • "Split-Brain" scenarios are now mitigated

BCUtils

  • All functionality related to styling is now transferred to the :bc_utils package.
  • Added a Banner after startup.
  • Logger filtering for Swarm and LibCluster noise reduction (via BCUtils.LoggerFilters)

ExESDB Logger Filtering

Features

The ExESDB.LoggerFilters module provides additional log noise reduction specifically for ExESDB's distributed systems components:

  • Ra Consensus Filtering: Reduces Ra heartbeat, append_entries, pre_vote, request_vote, and routine state transition messages while preserving all errors/warnings
  • Khepri Database Filtering: Filters internal Khepri operations (cluster state, store operations) at info/debug levels while maintaining error/warning visibility
  • Enhanced Swarm Filtering: Complements BCUtils filtering with additional ExESDB-specific Swarm noise reduction
  • Enhanced LibCluster Filtering: Complements BCUtils filtering with additional ExESDB-specific cluster formation noise reduction

Benefits

  • Dramatically improves log readability in development and production environments
  • Intelligent filtering preserves all error and warning messages
  • Focused on ExESDB-specific distributed systems infrastructure (Ra, Khepri)
  • Works in conjunction with BCUtils.LoggerFilters for comprehensive noise reduction

ExESDBGater

  • The ExESDB.GatewayAPI is moved to the :ex_esdb_gater package.

Features

Snapshots Subsystem provides cluster wide support for reading and writing snapshots, using a key derived from the source_uuid, stream_uuid and version of the snapshot.

version 0.0.16 (2025.06.26)

Snapshots

Features

Snapshots Subsystem provides cluster wide support for reading and writing snapshots, using a key derived from the source_uuid, stream_uuid and version of the snapshot.

  • record_snapshot/5 function
  • delete_snapshot/4 function
  • read_snapshot/4 function
  • list_snapshots/3 function

Supported by Gateway API

It is advised to use ExESDB.GatewayAPI to access the Snapshots Subsystem.

version 0.0.15 (2025.06.15)

Subscriptions

Transient subscriptions

  • :by_stream, :by_event_type, :by_event_pattern, :by_event_payload
  • Events are forwarded to Phoenix.PubSub for now

Persistent subscriptions

  • :by_stream, with support for replaying from a given version
  • Events are forwarded to a specific subscriber process
  • ack_event/3 function is provided

"Follow-the-Leader"

Emitter processes are automatically started on the leader node, when a new leader is elected.

Gateway API

  • A cluster-wide gateway API is provided
  • is an entry point for all the other modules
  • provides basic High-Availability and Load-Balancing

version 0.0.9-alpha (2025.05.04)

Subscriptions

  • ExESDB.Subscriptions module
  • func_registrations.exs file
  • emitter trigger in khepri now only uses the erlang-native :pg library (process groups)

Skeleton support for Commanded

  • ExESDB.Commanded.Adapter module
  • ExESDB.Commanded.Mapper module

version 0.0.8-alpha

2025.04.13

  • Added ExESDB.EventStore.stream_forward/4 function
  • Added BeamCampus.ColorFuncs module
  • Added ExESDB.Commanded.Adapter module
  • Refactored ExESDB.EventStreamReader and ExESDB.EventStreamWriter modules:
  • Streams are now read and written using the ExESDB.Streams module
  • Removed ExESDB.EventStreamReader module
  • Removed ExESDB.EventStreamWriter module

version 0.0.7-alpha

version 0.0.1-alpha

2025.03.25

  • Initial release