Changes and removals for Oban 3.0 [HOLD]

[sorentwo]

To be changed before Oban 3.0:

Defaults

• Use scheduled_at as unique timestamp by default
• Set default priority to 1 rather than 0

Normalization

• Normalize telemetry states from executor (success => completed, etc)
• Normalize database states from drain_queue/1 (discard => discarded, success => completed, etc.)
• Remove Oban.Migrations alias

Worker

• Remove :discard and {:discard, reason} return values
• Handle any size :error tuple, not just {:error, reason}
• Don't wrap exceptions from return values in a PerformError

Config

• Remove top-level crontab option
• Remove support for Oban.Queue.BasicEngine name
• Remove support for Oban.Plugins.Stager config
• Remove Oban.PostgresNotifier name
• Remove Oban.Peers.Postgres name
• Remove top-level circuit_backoff option
• Remove use of DYNO for node name
• Configure repo log level through {Repo, opts}

Plugins

• Remove Repeater plugin
• Remove Gossip plugin

Schema / Database

• Collapse Postgres migrations
• Use JSONB instead of arrays
• Use UUIDv7 for ids

Queue

• Remove producer telemetry event

Telemetry

• Default to structured logs, not JSON in default logger
• Include crash_reason in exception logs
• Set the log output domain to oban
• Automatically attach logger on init (disable with log level)

⚠️ This is for tracking purposes as we have no intention of releasing 3.0 soon. Please do not send PRs!

[yordis]

Adding some context,

The discarded state is for internal use and should strictly mean when a job exhausts all retries. Cancelled is the appropriate state instead.

[grzuy]

• Set the log output domain to oban

This was done in #1364.
Can be removed from the list I guess.