WaterDrop Instrumentation Events¶

This page lists all available instrumentation events for WaterDrop.

Overview¶

WaterDrop 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 the complete list of instrumentation events available in WaterDrop:

Buffer Events¶

buffer.flushed_async
buffer.flushed_sync
buffer.purged

Error Events¶

error.occurred

Message Events¶

message.acknowledged
message.buffered
message.produced_async
message.produced_sync
message.purged

Messages Events¶

messages.buffered
messages.produced_async
messages.produced_sync

Oauthbearer Events¶

oauthbearer.token_refresh

Producer Events¶

producer.closed
producer.closing
producer.connected
producer.disconnected
producer.disconnecting
producer.reload
producer.reloaded

Statistics Events¶

statistics.emitted

Transaction Events¶

transaction.aborted
transaction.committed
transaction.finished
transaction.marked_as_consumed
transaction.started

Usage Example¶

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

WaterDrop::App.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.

Class-Level Events¶

WaterDrop also provides class-level instrumentation that allows you to monitor events across all producer instances. This is useful for external libraries and monitoring tools that need to hook into producer lifecycle events without requiring specific producer instance references.

Available Class-Level Events¶

Connection_pool Events¶

connection_pool.created
connection_pool.reload
connection_pool.reloaded
connection_pool.setup
connection_pool.shutdown

Producer Events¶

producer.configured
producer.created

Class-Level Usage Example¶

# Subscribe to global producer lifecycle events
WaterDrop.monitor.subscribe('producer.configured') do |event|
  producer = event[:producer]
  puts "Producer configured: #{producer.id}"

  # Example: Add middleware after producer is fully configured
  producer.middleware.append do |message|
    message
  end
end

# All producers will now trigger the above callback
producer = WaterDrop::Producer.new do |config|
  config.kafka = { 'bootstrap.servers': 'localhost:9092' }
end

For more details on class-level instrumentation patterns, see the Monitoring and Logging documentation.

Last modified: 2025-12-08 17:38:16