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Date: Mon, 11 Oct 2010 22:06:41 -0500
Message-ID: <AANLkTinrSRfAy3_JVe+kZKVEd7Rj1MsyQYATiOu86AGL@mail.gmail.com>
Subject: Re: getSchemaVersion
From: Jonathan Ellis <jbellis@gmail.com>
To: user <user@cassandra.apache.org>
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On Mon, Oct 11, 2010 at 9:48 PM, B. Todd Burruss <bburruss@real.com> wrote:
> i was actually doing this to start with and was worried that i could have
> two clients modifying schemas at the same time. =A0it seems this could ca=
use
> multiple valid versions and a race condition. =A0maybe it simply "works o=
ut"
> that i wait until only one version is in the map, *if* get the version ma=
p
> from the same host that i used to modify the schema?

I don't think you need to worry about that specific scenario but the
whole schema change code is designed with the precondition that you
are only making changes from one node at a time.  If you can't make
that assumption then you need to lock.

--=20
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com