Upgrading to Newer Releases

This section of the documentation enumerates all the changes in gnsq from release to release and how you can change your code to have a painless updating experience.

Use the pip command to upgrade your existing Flask installation by providing the --upgrade parameter:

$ pip install --upgrade gnsq

Version 1.0.0

While there are no breaking changes in version 1.0.0, much of the interface has been deprecated to both simplify the api and bring it into better compliance with the recommended naming schemes for nsq clients. Existing code should work as is and deprecation warnings will be emitted for any code paths that need to be changed.

Deprecated Reader

The main interface has been renamed from Reader to Consumer. The api remains largely the same and can be swapped out directly in most cases.

Async messages

The async flag has been removed from the Consumer. Instead messages has a message.enable_async() method that may be used to indicate that a message will be handled asynchronous.

Max concurrency

The max_concurrency parameter has been removed from Consumer. If you wish to replicate this behavior, you should use the gnsq.contrib.QueueHandler in conjunction with a worker pool:

from gevent.pool import Pool
from gnsq import Consumer
from gnsq.contrib.queue import QueueHandler


# Create your consumer as usual
consumer = Consumer(
    'topic', 'worker', 'localhost:4150', max_in_flight=16)

# Connect a queue handler to the on message signal
queue = QueueHandler()

# Start your consumer without blocking or in a separate greenlet

# If you want to limit your concurrency to a single greenlet, simply loop
# over the queue in a for loop, or you can use a worker pool to distribute
# the work.
results = pool.imap_unordered(queue, my_handler)

# Consume the results from the pool
for result in results:

Deprecated Nsqd

The Nsqd client has been split into two classes, corresponding to the tcp and http APIs. The new classes are NsqdTCPClient and NsqdHTTPClient respectively.

The methods publish_tcp, publish_http, multipublish_tcp, and multipublish_http have been removed from the new classes.

Deprecated Lookupd

The Lookupd class has been replaced by LookupdClient. LookupdClient can be constructed using the host and port or by passing the url to LookupdClient.from_url() instead.

The method tombstone_topic_producer() has been renamed to tombstone_topic().