Oban Background Jobs Reference
Quick reference for Elixir Oban patterns.
Oban Pro Detection
Before applying patterns, check for Oban Pro:
grep -E "oban_pro|oban_web" mix.exs
grep -r "use Oban.Pro.Worker" lib/
grep -r "Oban.Pro.Engines.Smart" config/If Oban Pro detected, use Pro patterns for ALL new workers:
| Standard Oban | Oban Pro |
|---|---|
use Oban.Worker | use Oban.Pro.Worker |
def perform(%Job{}) | def process(%Job{}) |
Oban.Testing | Oban.Pro.Testing |
| Advisory lock engine | Oban.Pro.Engines.Smart |
Pro features (all optional): args_schema (typed args), Workflows, Batches, Chunks, Relay, hooks, encryption, deadlines, chaining, Smart Engine (global concurrency + rate limiting). Pro plugins (DynamicCron, DynamicLifeline, DynamicPruner) enhance OSS equivalents — swap module, don't run both. See ${CLAUDE_SKILL_DIR}/references/oban-pro-basics.md for all patterns and migration guide.
Iron Laws — Never Violate These
- JOBS MUST BE IDEMPOTENT — Safe to retry. Use idempotency keys for payments
- JOBS MUST STORE IDs, NOT STRUCTS — JSON serialization.
%{user_id: 1}not%{user: %User{}} - JOBS MUST HANDLE ALL RETURN VALUES —
:ok,{:error, _},{:cancel, _},{:snooze, _} - ARGS USE STRING KEYS — Pattern match
%{"user_id" => id}not%{user_id: id} - UNIQUE CONSTRAINTS FOR USER ACTIONS — Prevent double-click duplicates
- NEVER STORE LARGE DATA IN ARGS — Store references (IDs, paths), not content
- SMART ENGINE: NEVER USE
attemptTO LIMIT SNOOZES — Snooze rolls back attempt counter. Usemeta["snoozed"]instead. Causes infinite loops
Quick Worker Template
defmodule MyApp.Workers.ExampleWorker do
use Oban.Worker,
queue: :default,
max_attempts: 5,
unique: [period: {5, :minutes}, keys: [:entity_id]]
@impl Oban.Worker
def perform(%Oban.Job{args: %{"entity_id" => id}}) do
case process(id) do
{:ok, _} -> :ok
{:error, :not_found} -> {:cancel, "Entity not found"}
{:error, :rate_limited} -> {:snooze, {5, :minutes}}
{:error, reason} -> {:error, reason}
end
end
endReturn Value Meanings
| Return | State | Behavior |
|---|---|---|
:ok | completed | Success |
{:ok, value} | completed | Success with value |
{:error, reason} | retryable | Retry with backoff |
{:cancel, reason} | cancelled | Stop permanently |
{:snooze, seconds} | scheduled | Delay and retry |
Quick Decisions
Which Queue?
- Critical operations → High concurrency (20+)
- Mailers/Webhooks (I/O) → Medium concurrency (30-50)
- CPU-intensive → Low concurrency (3-5)
- External APIs → Use
dispatch_cooldownfor rate limiting
Testing Pattern
use Oban.Testing, repo: MyApp.Repo
# Assert enqueued
assert_enqueued worker: MyApp.Worker, args: %{id: 1}
# Execute and verify
assert :ok = perform_job(MyApp.Worker, %{id: 1})Common Anti-patterns
| Wrong | Right |
|---|---|
%{user_id: id} pattern match | %{"user_id" => id} (string keys) |
%{user: %User{}} in args | %{user_id: 1} (IDs only) |
| No idempotency for payments | Use idempotency keys |
| Ignoring return values | Handle all outcomes explicitly |
References
For detailed patterns, see:
${CLAUDE_SKILL_DIR}/references/worker-patterns.md- Worker options, backoff, timeout${CLAUDE_SKILL_DIR}/references/queue-config.md- Queue design, pool sizing, cron, Smart Engine${CLAUDE_SKILL_DIR}/references/testing-patterns.md- Testing, assertions, drain (OSS + Pro)${CLAUDE_SKILL_DIR}/references/oban-pro-basics.md- Pro.Worker, Workflow, Batch, Chunk, Relay, plugins