A demo for redis transation's strong exception guarantee.

gistfile1.py

"""
A demo for redis transation's strong exception guarantee.
"""
import logging
import redis

client = redis.StrictRedis(host="127.0.0.1",
                  port=6379,
                  db=1)


client.set("hello", 1)


def foo():
    with client.pipeline() as pipe:
        pipe.set("hello", 2)
        raise Exception("An exception throwed")


def bar():
    def transaction_func(pipe):
        hello_value = int(pipe.get("hello"))
        pipe.multi()
        pipe.set("hello", hello_value+1)
        raise Exception("Another exception throwed")
    client.transaction(transaction_func, "hello")

try:
    foo()
except Exception as e:
    logging.exception(e)

print client.get("hello") # Note the value will not be changed since the operation failed. Redis is still in valid state


try:
    bar()
except Exception as e:
    logging.exception(e)

print client.get("hello") # this is the same