Task Priorities¶

FastWorker supports four priority levels for task execution.

Priority Levels¶

Priority	Value	Description
`CRITICAL`	0	Highest priority, processed first
`HIGH`	1	High priority
`NORMAL`	2	Default priority
`LOW`	3	Lowest priority, processed last

Using Priorities¶

With Enum¶

from fastworker import Client
from fastworker.tasks.models import TaskPriority

client = Client()
await client.start()

# Critical - processed first
await client.delay("urgent_alert", data, priority=TaskPriority.CRITICAL)

# High priority
await client.delay("important_task", data, priority=TaskPriority.HIGH)

# Normal (default)
await client.delay("regular_task", data, priority=TaskPriority.NORMAL)

# Low - processed last
await client.delay("background_task", data, priority=TaskPriority.LOW)

With String¶

await client.delay("my_task", priority="critical")
await client.delay("my_task", priority="high")
await client.delay("my_task", priority="normal")
await client.delay("my_task", priority="low")

How Priority Works¶

Separate Queues¶

Each priority level has its own queue:

Control Plane
├── Critical Queue ──> Processed first
├── High Queue ──────> Processed second
├── Normal Queue ────> Processed third
└── Low Queue ───────> Processed last

Processing Order¶

Workers always check the CRITICAL queue first
If CRITICAL is empty, check HIGH
If HIGH is empty, check NORMAL
If NORMAL is empty, check LOW

This means:

Critical tasks are never delayed by lower-priority tasks
Low-priority tasks may be delayed if higher-priority tasks keep arriving

Port Allocation¶

Each priority level uses a different port:

Priority	Port Offset	Example (base 5555)
CRITICAL	Base + 0	5555
HIGH	Base + 1	5556
NORMAL	Base + 2	5557
LOW	Base + 3	5558

Use Cases¶

Critical Priority¶

Use for:

System alerts
Security events
User-blocking operations

await client.delay("send_security_alert", user_id, priority=TaskPriority.CRITICAL)

High Priority¶

Use for:

Important business operations
Time-sensitive processing
User-facing notifications

await client.delay("send_order_confirmation", order_id, priority=TaskPriority.HIGH)

Normal Priority (Default)¶

Use for:

Standard background tasks
Regular processing

await client.delay("process_upload", file_id)  # Uses NORMAL by default

Low Priority¶

Use for:

Analytics and logging
Cleanup tasks
Non-urgent processing

await client.delay("track_analytics", event_data, priority=TaskPriority.LOW)

Best Practices¶

1. Use Critical Sparingly¶

# Good - actual critical task
await client.delay("fraud_alert", transaction_id, priority=TaskPriority.CRITICAL)

# Bad - not really critical
await client.delay("send_newsletter", priority=TaskPriority.CRITICAL)

2. Default to Normal¶

Most tasks should use the default NORMAL priority:

# Let most tasks be normal
await client.delay("process_data", data)  # Normal is default

3. Use Low for Background Work¶

# Analytics can wait
await client.delay("track_page_view", page_data, priority=TaskPriority.LOW)

# Cleanup can wait
await client.delay("cleanup_temp_files", priority=TaskPriority.LOW)

4. Monitor Queue Sizes¶

Watch for queues building up, which indicates:

Too many high-priority tasks
Not enough workers
Tasks taking too long

Viewing Queues¶

Via Management GUI¶

The built-in GUI at http://127.0.0.1:8080 shows queue sizes for each priority level.

Via REST API¶

curl http://127.0.0.1:8080/api/queues

Returns:

{
  "queues": {
    "critical": {"count": 0, "tasks": []},
    "high": {"count": 1, "tasks": [{"id": "abc123", "name": "urgent_task"}]},
    "normal": {"count": 3, "tasks": [...]},
    "low": {"count": 1, "tasks": [...]}
  },
  "total_queued": 5
}