Cql-client NPM

cql-client

Node.js driver for cassandra on Cassandra Binary Protocol v2.

Features

CQL binary protocol v2
Automatic discovery of cluster peers
Fail-over cluster peers
Retry queries when disconnected from servers
Paging large result set with paging state
Events

Quick start

var client = require('cql-client').createClient({
  hosts: ['127.0.0.1']
});

client.execute('SELECT * FROM system.peers', function(err, rs) {
  var rows = rs.rows;
  rows.forEach(function(row) {
    console.log(row.peer);
    console.log(row.host_id);
    ..
  });
});

Usage

Install library

npm install cql-client --save

Create a client

var cql = require('cql-client');
var client = cql.createClient({ hosts: ['127.0.0.1'], keyspace: 'ks' });

Execute queries

client.execute('SELECT * FROM table', function(err, rs) {
  rs.rows.forEach(function(row) {
    console.log(row);
  });
});

Execute prepared queries

client.execute(
  'INSERT INTO table (id, v1, v2) VALUES (?, ?, ?)',
  [1000, 'foo', 'bar'],
  function(err) {
    ...
  }
);

Batch

var batch = client.batch();
batch.add('UPDATE table SET v1 = ? WHERE id = ?', ['101', 1001]);
batch.add('UPDATE table SET v1 = ? WHERE id = ?', ['101', 1001]);
batch.add('DELETE FROM table WHERE id = ?', ['102']);
batch.commit(function(err) {
  ..
});

Read data with cursor

var cursor = client.execute('SELECT * FROM table', function(err, rs) {
  var cursor = rs.cursor();
  cursor.on('row', function(row) {
    console.log(row);
  });
  cursor.on('error', function(err) {
    ..
  });
  cursor.on('end', function() {
    console.log('done');
  });
});

API

CQL

cql.createClient(options)

Create a client with options. The created client will connect the cluster automatically.

options
hosts List of cassandra hosts you are connecting to. Use array to connect multiple hosts.
keyspace Name of the default keyspace.
autoDetect Set true to detect peers automatically. (Optional)
connsPerHost The size of connection pool per host. (Default: 2)
connectTimeout Milliseconds to determine connections are timed out. (Default: 5000)
reconnectInterval Milliseconds of interval for reconnecting. (Default: 5000)
preparedCacheSize Size of cache for prepared statement. (Default: 10000)

Client

client.connect(cb)

Connect to the cluster. Note that you do not need to call the method since client will connect automatically.

cb callback when connected

client.close()

Close the connection to the cluster.

client.getAvailableConnection()

Get available connection from connections.

client.execute(query, values, options, callback)

Execute CQL. It will use prepared query when values are specified.

query Query statement to be executed.
values Array of bound values.
options
consistencyLevel Consistency level of the query. cql.CL.ONE,THREE,QUORUM,ALL,LOCAL_QUORUM,EACH_QUORUM
pageSize Paging size of the result.
pagingState Paging state of the query.
serialConsistency Serial consistency of the query.
callback Callback with error and result set.