There are 3 different things we are talking here
1. SimpleStrategy vs. NetworkTopology matter when you have single DC vs.
Multiple DC's2. In both cases you can specific replication factor, obviously in
SimpleStratgey case you dont mention DC whereas in NetworkTopology, you can
mentione mutiple options by each DC's replication requirements.3. Now if your
question is referred to single DC then even if your System keyspace is
SimpleStartegy and your user table is NetworkToplogy, it should not matter and
Table_Test will be created in all nodes4. If your System_auth KS is set less
than number of nodes, you will face AUTH issues. Naidu Saladi
From: 鄢来琼 <laiqiong....@gtafe.com>
To: "user@cassandra.apache.org" <user@cassandra.apache.org>
Sent: Monday, March 16, 2015 2:13 AM
Subject: Re: Is Table created in all the nodes if the default consistency
level used
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div.yiv5346526530WordSection1 {}#yiv5346526530 Hi Daemeon, Yes, I use
“NetworkTopologyStrategy” strategy for “Table_test”, but “System keyspace” is
Cassandra internal keyspace, its strategy is localStrategy. So my question is
how to guarantee “Table_test” is created in all the nodes before any R/W
opertions? Thanks. Peter
发件人: daemeon reiydelle [mailto:daeme...@gmail.com]
发送时间: 2015年3月16日 14:35
收件人: user@cassandra.apache.org
主题: Re: Is Table created in all the nodes if the default consistency level used
If you want to guarantee that the data is written to all nodes before the
code returns, then yes you have to use "consistency all". Otherwise there is a
small risk of outdated data being served if a node goes offline longer than
hints timeouts. Somewhat looser options that can assure multiple copies are
written, as you probably know, are quorum or a hard coded value. This applies
to a typical installation with a substantial number of nodes of course, not a
small 2-3 node cluster. I am curious why localStrategy when you have such
concerns about data consistency that you want to assure all nodes get data
written. Can you elaborate on your use case?
.......
“Life should not be a journey to the grave with the intention of arriving
safely in a
pretty and well preserved body, but rather to skid in broadside in a cloud of
smoke,
thoroughly used up, totally worn out, and loudly proclaiming “Wow! What a Ride!”
- Hunter Thompson
Daemeon C.M. Reiydelle
USA (+1) 415.501.0198
London (+44) (0) 20 8144 9872 On Sun, Mar 15, 2015 at 8:11 PM, 鄢来琼
<laiqiong....@gtafe.com> wrote: Could you tell me whether the meta data of the
new table are build in all the nodes after execute the following statement.
cassandra_session.execute_async( “““CREATE TABLE Table_test( ID uuid,
Time timestamp, Value double, Date timestamp, PRIMARY KEY
((ID,Date), Time) ) WITH COMPACT STORAGE; ””” ) As I know, the system
keyspace is used to store the meta data, but the strategy is localStrategy,
which only store meta data of local node. So I want to know whether table is
created in all the nodes, should I add consistency_level setting to the above
statement to make sure “create table” will be executed in all the nodes?
Thanks. Peter
