如何连接到本地cassandra db [英] How do I connect to local cassandra db

问题描述

我有一个本地运行的cassandra db。我可以看到它在Ops中心工作。但是，当我打开开发中心并尝试连接我得到一个隐藏的无法连接的错误。

如何获得我需要的确切的名称/ connectionstring

解决方案

要连接到的主机名/ IP在 listen_address 属性。如果您只从您的本地主机（沙箱计算机）连接到Cassandra，那么您可以设置 listen_address 在您的cassandra.yaml中：

  listen_address：localhost 
  / pre> 
 
 
当您启动Cassandra时，您应该在STDOUT或system.log中看到与此相似的行（为了简洁，删除时间戳）：
 开始在localhost / 127.0.0.1上监听CQL客户端：9042 ... 
绑定节俭服务到localhost / 127.0.0.1：9160 
聆听thrift客户端... 
  
这些行表示您应该使用哪个地址连接到您的群集。第一种测试连接的方法是使用 clqsh 。注意，cqlsh默认会连接到localhost。如果您连接到除localhost之外的主机/ IP，则需要在命令行上指定。
  $ cqlsh 
连接到本地主机上的测试集群：9042。 
 [cqlsh 5.0.1 |. Cassandra 2.1.0-rc5-SNAPSHOT | CQL spec 3.2.0 |本机协议v3] 
使用HELP获取帮助。 
 cqlsh> 
  
如果这个工作正常，那么你也应该能够从DataStax Dev Center通过定义到localhost的连接，如下所示：
 
 
 
  
 
 
 
此时，您应该能够通过应用程序代码连接（显示Java CQL3驱动程序）：
  cluster = Cluster.builder（）。addContactPoint（localhost）。 
元数据元数据= cluster.Metadata; 
 Console.WriteLine（Connected to cluster：+ metadata.ClusterName.ToString（））; 
会话session = cluster.connect（）; 
  
 
I have a cassandra db running locally.  I can see it working in Ops Center.  However, when I open dev center and try to connect I get a cryptic "unable to connect" error.

How can I get the exact name / connectionstring that I need to use to connect to this local cassandra db via dev center?
解决方案
The hostname/IP to connect to is specified in the listen_address property of your cassandra.yaml.If you are connecting to Cassandra from your localhost only (a sandbox machine), then you can set the listen_address in your cassandra.yaml accordingly:
listen_address: localhost
When you start Cassandra, you should see lines similar to this either in STDOUT or in your system.log (timestamps removed for brevity):
Starting listening for CQL clients on localhost/127.0.0.1:9042...
Binding thrift service to localhost/127.0.0.1:9160
Listening for thrift clients...
These lines indicate which address you should be using to connect to your cluster.  The first way to test your connection, is with clqsh.  Note that cqlsh will connect to "localhost" by default.  If you are connecting to a host/IP other than localhost, then you will need to specify it on the command line.
$ cqlsh
Connected to Test Cluster at localhost:9042.
[cqlsh 5.0.1 | Cassandra 2.1.0-rc5-SNAPSHOT | CQL spec 3.2.0 | Native protocol v3]
Use HELP for help.
cqlsh>
If this works, then you should also be able to connect (and test) from DataStax Dev Center (also on your local machine) by defining a connection to localhost, like this:



At this point, you should be able to connect via your application code (Java CQL3 driver shown):
cluster = Cluster.builder().addContactPoint("localhost").build();
Metadata metadata = cluster.Metadata;
Console.WriteLine("Connected to cluster: " + metadata.ClusterName.ToString());
Session session = cluster.connect();


                        
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