Library for setting up concurrent consumers of data stored inside
PostgreSQL database in a simple, declarative manner.
See the examples/ directory for a usage example.
If you want to add metrics, see the
consumers-metrics-prometheus
package to seamlessly instrument your consumer.
Changes
consumers-2.3.3.1 (2025-04-03)
Do not prepare query that updates jobs in the monitor thread.
consumers-2.3.3.0 (2025-03-03)
Add ccJobLogData to ConsumerConfig to improve logging.
consumers-2.3.2.0 (2024-08-30)
Use prepared queries to improve parsing and planning time.
Prevent the consumer from crashlooping if ccOnException throws.
Drop support for GHC 8.8.
consumers-2.3.1.0 (2023-11-27)
Drop support for advisory locks.
Add support for GHC 9.6 and 9.8.
Apply ccOnException when freeing jobs reserved by an inactive consumer.
consumers-2.3.0.0 (2022-07-07)
Update to monad-time 0.4.0.0.
Support for GHC 9.2.
Drop support for GHC < 8.8.
consumers-2.2.0.6 (2021-10-22)
Improve efficiency of the SQL query that reserves jobs.
consumers-2.2.0.5 (2021-10-12)
Adjust to changes in log-base-0.11.
consumers-2.2.0.4 (2021-06-09)
Adjust to changes in log-base-0.10.
consumers-2.2.0.3 (2021-05-28)
Support GHC 9.0.
consumers-2.2.0.2 (2020-05-05)
Support hpqtypes-1.9.0.0 and relax base.
consumers-2.2.0.1 (2019-05-22)
Support hpqtypes-1.7.0.0 and hpqtypes-extras-1.9.0.0.
consumers-2.2.0.0 (2019-02-19)
When jobs are relased from a dead consumer, reset their finished_at column.
Start the consumer only when ccMaxRunningJobs >= 1.
consumers-2.1.2.0 (2018-07-11)
Support hpqtypes-1.6.0.0.
Drop support for GHC < 8.
consumers-2.1.1.0 (2018-03-18)
GHC 8.4.1 support.
consumers-2.1.0.0 (2017-09-18)
Added a MonadTime constraint to runConsumer. The currentTime
method from MonadTime is now used instead of now() in SQL. This
is mostly useful for testing, to control the flow of time in test
cases.
Added a new runConsumer variant: runConsumerWithIdleSignal.
When a consumer is idle, this variant signals a TMVar. This is
mostly useful for testing.
