aiozk 0.18.0

Asyncio client for Zookeeper.

Asyncio zookeeper client

Based on wglass/zoonado implementation

Status

Have no major bugs in client/session/connection, but recipes are just ported and require more tests. So you can expect that recipes with tests are working.

Installation

$ pip install aiozk

Quick Example

import asyncio
from aiozk import ZKClient


async def run():
    zk = ZKClient('localhost')
    await zk.start()
    await zk.create('/foo', data=b'bazz', ephemeral=True)
    await zk.set_data('/foo', 'new bazz')
    await zk.close()

loop = asyncio.get_event_loop()
loop.run_until_complete(run())

Recipes

You may use recipes, similar to zoonado, kazoo, and other libs:

# assuming zk is aiozk.ZKClient

barrier = zk.recipes.Barrier('/barrier_name')
await barrier.create()
await barrier.lift()
await barrier.wait()

Full list of recipes

To understand ideas behind recipes please read this and even more recipes here. Make sure you're familiar with all recipes before doing something new by yourself, especially when it involves more than few zookeeper calls.

Testing

NB: please ensure that you're using recent docker-compose version. You can get it by running

pip install --user -U docker-compose

Run tests

# you should have access to docker

docker-compose build
./test-runner.sh

Testing approach

Most of tests are integration tests and running on real zookeeper instances. We've chosen zookeeper 3.5 version since it has an ability to dynamic reconfiguration and we're going to do all connecting/reconnecting/watches tests on zk docker cluster as this gives us the ability to restart any server and see what happens.

# first terminal: launch zookeeper cluster
docker-compose rm -fv && docker-compose build zk && docker-compose scale zk=7 && docker-compose up zk_seed zk

# it will launch cluster in this terminal and remain. last lines should be like this:

zk_6       | Servers: 'server.1=172.23.0.9:2888:3888:participant;0.0.0.0:2181\nserver.2=172.23.0.2:2888:3888:participant;0.0.0.0:2181\nserver.3=172.23.0.3:2888:3888:participant;0.0.0.0:2181\nserver.4=172.23.0.4:2888:3888:participant;0.0.0.0:2181\nserver.5=172.23.0.5:2888:3888:participant;0.0.0.0:2181\nserver.6=172.23.0.7:2888:3888:participant;0.0.0.0:2181'
zk_6       | CONFIG: server.1=172.23.0.9:2888:3888:participant;0.0.0.0:2181
zk_6       | server.2=172.23.0.2:2888:3888:participant;0.0.0.0:2181
zk_6       | server.3=172.23.0.3:2888:3888:participant;0.0.0.0:2181
zk_6       | server.4=172.23.0.4:2888:3888:participant;0.0.0.0:2181
zk_6       | server.5=172.23.0.5:2888:3888:participant;0.0.0.0:2181
zk_6       | server.6=172.23.0.7:2888:3888:participant;0.0.0.0:2181
zk_6       | server.7=172.23.0.6:2888:3888:observer;0.0.0.0:2181
zk_6       |
zk_6       |
zk_6       | Reconfiguring...
zk_6       | ethernal loop
zk_7       | Servers: 'server.1=172.23.0.9:2888:3888:participant;0.0.0.0:2181\nserver.2=172.23.0.2:2888:3888:participant;0.0.0.0:2181\nserver.3=172.23.0.3:2888:3888:participant;0.0.0.0:2181\nserver.4=172.23.0.4:2888:3888:participant;0.0.0.0:2181\nserver.5=172.23.0.5:2888:3888:participant;0.0.0.0:2181\nserver.6=172.23.0.7:2888:3888:participant;0.0.0.0:2181\nserver.7=172.23.0.6:2888:3888:participant;0.0.0.0:2181'
zk_7       | CONFIG: server.1=172.23.0.9:2888:3888:participant;0.0.0.0:2181
zk_7       | server.2=172.23.0.2:2888:3888:participant;0.0.0.0:2181
zk_7       | server.3=172.23.0.3:2888:3888:participant;0.0.0.0:2181
zk_7       | server.4=172.23.0.4:2888:3888:participant;0.0.0.0:2181
zk_7       | server.5=172.23.0.5:2888:3888:participant;0.0.0.0:2181
zk_7       | server.6=172.23.0.7:2888:3888:participant;0.0.0.0:2181
zk_7       | server.7=172.23.0.6:2888:3888:participant;0.0.0.0:2181
zk_7       | server.8=172.23.0.8:2888:3888:observer;0.0.0.0:2181
zk_7       |
zk_7       |
zk_7       | Reconfiguring...
zk_7       | ethernal loop

Run tests:

docker-compose run --no-deps aiozk
# last lines will be about testing results

............lot of lines ommited........
.
----------------------------------------------------------------------
Ran 3 tests in 1.059s

OK

Recipes testing

It seems that usually recipes require several things to be tested:

• That recipe flow is working as expected
• Timeouts: reproduce every timeout with meaningful values (timeout 0.5s and block for 0.6s)