Enhancements

• [Oban] Allow setting a MFA in :get_dynamic_repo

  Anonymous functions don't work with OTP releases, as anonymous functions cannot be used in configuration. Now a MFA tuple can be passed instead of a fun, and the scaling guide recommends a function instead.

• [Cron] Include configured timezone in cron job metadata

  Along with the cron expression, stored as cron_expr, the configured timezone is also recorded as cron_tz in cron job metadata.

• [Cron] Add next_at/2 and last_at/2 for cron time calculations

  This implements jumping functions for cron expressions. Rather than naively iterating through minutes, it uses the expression values to efficiently jump to the next or last cron run time.

• [Executor] Always convert queue_time to native time unit

  The telemetry docs state that measurements are recorded in native time units. However, that hasn't been the case for queue_time for a while now. It usually worked anyway native and nanosecond is of the same resolution, but now it is guaranteed.

Bug Fixes

• [Peer] Correct leadership elections for the Dolphin engine

  MySQL always returns the number of entries attempted, even when nothing was added. The previous match caused all nodes to believe they were the leader. This uses a secondary query within the same transaction to detect if the current instance is the leader.

• [Reindexer] Drop invalid indexes concurrently when reindexing.

  The DROP INDEX query would lock the whole table with an ACCESS EXCLUSIVE lock and could cause queries to fail unexpectedly.

• [Testing] Use Ecto.Type.cast/2 for backward compatibility

  The cast!/2 function wasn't added until Ecto 3.12. This reverts time casting to use cast/2 for compatibility with earlier Ecto versions.

• [Worker] Validate that the unique option isn't an empty list.

  An empty list was accepted at compile time, but wouldn't be valid later at runtime. Now the two validations match for greater parity.