Hi Everyone,
I was going thru Cassandra By Example Blog
http://www.rackspace.com/cloud/blog/2010/05/12/cassandra-by-example/ and I had
a question about the user sign up section:
username = 'jericevans'
password = '**********'
useruuid = str(uuid())
columns = {'id': useruuid, 'username': username, 'password': password}
USER.insert(useruuid, columns)
USERNAME.insert(username, {'id': useruuid})
How can I guarantee that USERNAME.insert(username, {'id': useruuid}) won't
overwrite someone else's account. What I mean is how can I guarantee that a
user's username doesn't already exist in Cassandra? I know I can check first,
but in a highly concurrent environment, there's a possibility that between
USER.insert(useruuid, columns) and USERNAME.insert(username, {'id': useruuid})
someone else does the same USERNAME.insert(username, {'id': useruuid}) and
hijack the user's account.
Seems like that USERNAME is something that the author has added since it's
missing in original Twissandra source code.
Thanks,
Drew
