Stats and Monitoring¶

MessageBus tracks per-channel counters automatically via a shared Stats instance.

Available Counters¶

For each channel named :orders, the following counters are tracked:

Counter	Description
`:orders_published`	Messages published
`:orders_delivered`	All subscribers ACKed (message fully delivered)
`:orders_nacked`	Explicit nacks by subscribers
`:orders_timed_out`	Delivery timeouts (auto-nack)
`:orders_dead_lettered`	Entries added to the DLQ
`:orders_throttled`	Publishes that were rate-limited

Reading Stats¶

bus.stats[:orders_published]     # => 42
bus.stats[:orders_delivered]     # => 40
bus.stats[:orders_dead_lettered] # => 2

Snapshot¶

Get all counters as a Hash:

bus.stats.to_h
# => { orders_published: 42, orders_delivered: 40, ... }

Reset¶

Zero all counters:

bus.stats.reset!

Or reset everything (channels + stats):

bus.clear!

Using Stats Directly¶

When using Channel without a MessageBus, pass a Stats instance:

stats = TypedBus::Stats.new
channel = TypedBus::Channel.new(:work, stats: stats, timeout: 5)

# ... publish and subscribe ...

stats[:work_published]  # => N

Monitoring Pattern¶

Combine stats with DLQ callbacks for real-time alerting:

bus.add_channel(:orders, timeout: 10)

bus.dead_letters(:orders).on_dead_letter do |delivery|
  error_rate = bus.stats[:orders_dead_lettered].to_f / bus.stats[:orders_published]
  if error_rate > 0.1
    alert("Orders DLQ error rate above 10%: #{(error_rate * 100).round}%")
  end
end