Karafka Instrumentation Events¶

This page lists all available instrumentation events for Karafka.

Overview¶

Karafka uses a notification system that allows you to monitor and hook into various stages of message processing and producer operations. You can subscribe to any of these events to add custom monitoring, logging, or other functionality.

Available Events¶

Below is a list of the instrumentation events available in Karafka. Depending on which Karafka extensions and additional engines you use, this might not be the complete list of all the events: some events are registered dynamically at runtime. Use #available_events on a fully loaded Karafka system to determine all the events you can use.

Active_job Events¶

active_job.consume
active_job.consumed

App Events¶

app.before_warmup
app.initialized
app.initializing
app.quiet
app.quieting
app.running
app.stopped
app.stopping
app.supervising
app.terminated

Client Events¶

client.events_poll
client.pause
client.reset
client.resume

Connection Events¶

connection.listener.after_fetch_loop
connection.listener.before_fetch_loop
connection.listener.fetch_loop
connection.listener.fetch_loop.received
connection.listener.pending
connection.listener.quiet
connection.listener.quieting
connection.listener.running
connection.listener.starting
connection.listener.stopped
connection.listener.stopping

Consumer Events¶

consumer.before_schedule_consume
consumer.before_schedule_eofed
consumer.before_schedule_idle
consumer.before_schedule_revoked
consumer.before_schedule_shutdown
consumer.before_schedule_tick
consumer.consume
consumer.consumed
consumer.consuming.pause
consumer.consuming.retry
consumer.consuming.seek
consumer.consuming.transaction
consumer.eof
consumer.eofed
consumer.idle
consumer.initialize
consumer.initialized
consumer.revoke
consumer.revoked
consumer.shutdown
consumer.shutting_down
consumer.tick
consumer.ticked
consumer.wrap
consumer.wrapped

Dead_letter_queue Events¶

dead_letter_queue.dispatched

Error Events¶

error.occurred

Filtering Events¶

filtering.seek
filtering.throttled

Oauthbearer Events¶

oauthbearer.token_refresh

Process Events¶

process.notice_signal

Rebalance Events¶

rebalance.partitions_assign
rebalance.partitions_assigned
rebalance.partitions_revoke
rebalance.partitions_revoked

Statistics Events¶

statistics.emitted

Swarm Events¶

swarm.manager.after_fork
swarm.manager.before_fork
swarm.manager.control
swarm.manager.stopping
swarm.manager.terminating
swarm.node.after_fork

Worker Events¶

worker.completed
worker.process
worker.processed
worker.scaling.down
worker.scaling.up

Usage Example¶

To subscribe to any of these events, you can use the instrumentation monitor:

Karafka.monitor.subscribe('event.name') do |event|
  # Your custom logic here
  puts "Event: #{event.id}"
  puts "Payload: #{event.payload}"
end

For more information about using instrumentation, please refer to the main documentation.

Last modified: 2026-08-12 18:42:23