Environment Variables

Configure TaskDaemon via environment variables

Environment Variables

Configure TaskDaemon via environment variables.

Available Variables

Variable	Default	Description
HANDLER_CONFIG	handlers.toml	Path to handler configuration file
DAEMON_PORT	8080	HTTP server port
DAEMON_GRPC_PORT	50051	gRPC server port
DAEMON_WORKERS	2	Number of worker threads
DAEMON_DB_PATH	/tmp/task_queue.db	SQLite database path
DAEMON_DB_MAX_CONNECTIONS	20	SQLite connection pool size
DAEMON_QUEUE_TYPE	sqlite	Queue type: sqlite or hybrid
DAEMON_TASK_SELECTION	fifo	Task selection: fifo, lifo, priority
DAEMON_LOG_LEVEL	info	Log level (trace, debug, info, warn, error)
DAEMON_HOST	0.0.0.0	HTTP server bind address
DAEMON_MAX_RETRIES	3	Maximum retry attempts for failed tasks
DAEMON_TASK_TIMEOUT	30	Default task timeout in seconds

Queue Types

sqlite

Standard SQLite-backed queue. Durable but slightly slower under high load.

DAEMON_QUEUE_TYPE=sqlite

hybrid

In-memory queue with SQLite persistence. Faster dequeue with durability.

DAEMON_QUEUE_TYPE=hybrid

Recommended for high-throughput workloads. Tasks are kept in memory for fast access but persisted to SQLite for crash recovery.

Task Selection

Value	Description
fifo	First-In-First-Out (default)
lifo	Last-In-First-Out
priority	Highest priority first

See Task Selection Strategies for details.

Usage

Docker

docker run -d \
  -e DAEMON_WORKERS=100 \
  -e DAEMON_QUEUE_TYPE=hybrid \
  -e DAEMON_TASK_SELECTION=priority \
  -e DAEMON_DB_MAX_CONNECTIONS=50 \
  -e DAEMON_LOG_LEVEL=info \
  -v ./handlers.toml:/app/handlers.toml \
  -v /var/run/docker.sock:/var/run/docker.sock \
  mshelia/taskdaemon

Docker Compose

services:
  taskdaemon:
    image: mshelia/taskdaemon:latest
    environment:
      - DAEMON_WORKERS=100
      - DAEMON_QUEUE_TYPE=hybrid
      - DAEMON_TASK_SELECTION=priority
      - DAEMON_DB_MAX_CONNECTIONS=50
      - DAEMON_LOG_LEVEL=info
    volumes:
      - ./handlers.toml:/app/handlers.toml
      - /var/run/docker.sock:/var/run/docker.sock
      - task-data:/data

volumes:
  task-data:

Shell

export DAEMON_WORKERS=100
export DAEMON_QUEUE_TYPE=hybrid
export DAEMON_TASK_SELECTION=fifo
./target/release/task-daemon --config handlers.toml

CLI Arguments

CLI arguments override environment variables:

CLI Flag	Environment Variable
--workers	DAEMON_WORKERS
--http-port	DAEMON_PORT
--grpc-port	DAEMON_GRPC_PORT
--db-path	DAEMON_DB_PATH
--log-level	DAEMON_LOG_LEVEL
--task-selection	DAEMON_TASK_SELECTION
--config	HANDLER_CONFIG

Precedence

Configuration is applied in this order (later overrides earlier):

1. Default values
2. Environment variables
3. CLI arguments

# DAEMON_WORKERS=4 in environment
# --workers 8 on command line
# Result: 8 workers (CLI wins)

Performance Tuning

For high-throughput workloads:

DAEMON_WORKERS=100              # Match to handler instances
DAEMON_QUEUE_TYPE=hybrid        # Faster dequeue
DAEMON_DB_MAX_CONNECTIONS=50    # More DB connections
DAEMON_TASK_SELECTION=fifo      # Predictable ordering

Set DAEMON_WORKERS to roughly match the total number of handler instances across all handlers for optimal utilization.

Log Levels

Level	Description
trace	Very detailed debugging
debug	Debugging information
info	General operational info
warn	Warning messages
error	Error messages only