Logging

Logger hierarchy

zmqtt uses the standard logging module with the following logger names:

zmqtt
  ├── zmqtt.client
  └── zmqtt.protocol

Configure any of these with the standard logging API.

Enabling logging

The simplest way to see all library output:

import logging
logging.basicConfig(level=logging.DEBUG)

For production, configure only the loggers you care about:

import logging
logging.getLogger("zmqtt.client").setLevel(logging.WARNING)
logging.getLogger("zmqtt.protocol").setLevel(logging.DEBUG)

What DEBUG output looks like

At DEBUG level, the protocol logger reports connection and packet activity. A typical stream contains:

DEBUG zmqtt.protocol  Connecting
DEBUG zmqtt.protocol  Sending 27 bytes
INFO  zmqtt.protocol  Connected
DEBUG zmqtt.protocol  Sent SUBSCRIBE
DEBUG zmqtt.protocol  Received PingResp()

At INFO level the client layer logs reconnection events:

WARNING zmqtt.client  Connection lost, reconnecting...
INFO    zmqtt.client  Successfully reconnected

Duplicate-filter warnings come from zmqtt.protocol (see Subscribing — Duplicate-filter guard):

WARNING zmqtt.protocol  Filter 'data/temp' already subscribed (ignored)

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See also: Reconnection · Error Handling