Database Reference
In-Depth Information
.../gitrep>git clone http://github.com/suguru/cassandra-webconsole.git
Initialized empty Git repository in C:/git/cassandra-webconsole/.git
remote: Counting objects: 604, done.
remote: Compressing objects: 100% (463/463), done.
remote: Total 604 (delta 248), reused 103 (delta 9)
Receiving objects: 100% (604/604), 6.24 MiB | 228 KiB/s, done.
Resolving deltas: 100% (248/248), done.
Now we have a subdirectory named after the Git project so that we can build the project and
start using it. This is enough to get you started so that you can run the clients. A full discussion
of Git is outside the scope of this topic, but you can read more about it at GitHub.com. There's
a good help section on how to get set up at
http://help.github.com
, and the site
http://gitref.org
offers a really good reference for beginners.
Connecting Client Nodes
Once your cluster is set up, it does not matter which node in the cluster your client connects to.
That's because Cassandra nodes are symmetrical, and any node will act as a proxy to a given
request, forwarding the request to the node that handles the desired range.
There are a few options here to keep things organized and efficient.
Client List
The most straightforward way to connect to a cluster is to maintain a list of the addresses or
hostnames of the servers in the cluster and cycle through them on the client side. You allow cli-
ents to choose among them according to some algorithm of your choosing, such as random or
sequential. In this way, you're setting up a sort of poor-man's client balancer.
This has the advantage of being the simplest to set up, and requires no intervention from opera-
tions. For testing, this is fine, but it ultimately will become difficult to manage.
Round-Robin DNS
Another option is to create a record in DNS that represents the set of servers in the cluster. Using
round-robin DNS allows clients to connect simply and cleanly. This has the significant advantage
of not requiring any maintenance or logic on the client side for connecting to different nodes,
and is the recommended approach.
Load Balancer
The third option is to have operations deploy a load balancer in front of the Cassandra cluster,
and then configure clients to connect to it. The load balancer will act as the configuration point.
