Cancel Directly from Job Execution
Discard was initially intended to mean “a job exhausted all retries.” Later, it
was added as a return type for perform/1, and it came to mean either “stop
retrying” or “exhausted retries” ambiguously, with no clear way to
differentiate. Even later, we introduced cancel with a cancelled state as a
way to stop jobs at runtime.
To repair this dichotomy, we’re introducing a new {:cancel, reason} return
type that transitions jobs to the cancelled state:
case do_some_work(job) do
{:ok, _result} = ok ->
ok
{:error, :invalid} ->
- {:discard, :invalid}
+ {:cancel, :invalid}
{:error, _reason} = error ->
error
end
With this change we’re also deprecating the use of discard from perform/1
entirely! The meaning of each action/state is now:
-
cancel—this job was purposefully stopped from retrying, either from a return
value or the cancel command triggered by a human -
discard—this job has exhausted all retries and transitioned by the system
You’re encouraged to replace usage of :discard with :cancel throughout your
application’s workers, but :discard is only soft-deprecated and undocumented
now.
Public Engine Behaviour
Engines are responsible for all non-plugin database interaction, from inserting
through executing jobs. They’re also the intermediate layer that makes Pro’s
SmartEngine possible.
Along with documenting the Engine this also flattens its name for parity with
other “extension” modules. For the sake of consistency with notifiers and peers,
the Basic and Inline engines are now Oban.Engines.Basic and
Oban.Engines.Inline, respectively.
v2.13.0 — 2022-07-22
Enhancements
-
[Telemetry] Add
encodeoption to make JSON encoding forattach_default_logger/1.Now it’s possible to use the default logger in applications that prefer
structured logging or use a standard JSON log formatter. -
[Oban] Accept a
DateTimefor the:with_scheduledoption when draining.When a
DateTimeis provided, drains all jobs scheduled up to, and
including, that point in time. -
[Oban] Accept extra options for
insert/2,4andinsert_all/2,4.These are typically the Ecto’s standard “Shared Options” such as
logand
timeout. Other engines, such as Pro’sSmartEnginemay support additional
options. -
[Repo] Add
aggregate/4wrapper to facilitate aggregates from plugins or
other extensions that useOban.Repo.
Bug Fixes
-
[Oban] Prevent empty maps from matching non-empty maps during uniqueness checks.
-
[Oban] Handle discarded and exhausted states for inline testing mode.
Previously, returning a
:discardtuple or exhausting attempts would cause an
error. -
[Peer] Default
leader?check to false on peer timeout.Timeouts should be rare, as they’re symptoms of application/database overload.
If leadership can’t be established it’s safe to assume an instance isn’t
leader and log a warning. -
[Peer] Use node-specific lock requester id for Global peers.
Occasionally a peer module may hang while establishing leadership. In this
case the peer isn’t yet a leader, and we can fallback tofalse. -
[Config] Validate options only after applying normalizations.
-
[Migrations] Allow any viable
prefixin migrations. -
[Reindexer] Drop invalid Oban indexes before reindexing again.
Table contention that occurs during concurrent reindexing may leave indexes in
an invalid, and unusable state. Those indexes aren’t used by Postgres and they
take up disk space. Now the Reindexer will drop any invalid indexes before
attempting to reindex. -
[Reindexer] Only rebuild
argsandmetaGIN indexes concurrently.The new
indexesoption can be used to override the reindexed indexes rather
than the defaults.The other two standard indexes (primary key and compound fields) are BTREE
based and not as subject to bloat. -
[Testing] Fix testing mode for
perform_joband alt engines, e.g. InlineA couple of changes enabled this compound fix:
- Removing the engine override within config and exposing a centralized
engine lookup instead. - Controlling post-execution db interaction with a new
ackoption for
the Executor module.
- Removing the engine override within config and exposing a centralized
Deprecations
- [Oban] Soft replace discard with cancel return value
