Apache Cassandra access with cassandra-driver

-connect-and-query.js

const cassandra = require('cassandra-driver');

const readline = require('readline');

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

const client = new cassandra.Client({ contactPoints: ['10.69.72.113'] });
client.connect(function (err) {
  if (err) return console.error(err);
  console.log('Connected to cluster with %d host(s): %j', client.hosts.length, client.hosts.keys());
  
  console.log(client.metadata.keyspaces.micapsdataserver.tables);
});
/*
client.metadata.getTable('ks1', 'table1')
  .then(function (tableInfo) {
    console.log('Table %s', table.name);
    table.columns.forEach(function (column) {
       console.log('Column %s with type %j', column.name, column.type);
    });
  });


 
const query = 'SELECT cql_version FROM system.local';
const result = client.execute(query, function (err, result) {
  if (err) return console.error(err);
  
  console.log(result.rows);
} );*/

const processLine = (line)=>{
	//const query = 'SELECT cql_version FROM system.local';
	const query = line;
	const result = client.execute(query, function (err, result) {
	  if (err) return console.error(err);
	  
	  if(! result.rows) return console.log("execute finished!");
	  console.log(result.rows.length);
	  for(let val of result.rows){
		console.log(val);
	  }
	});
}

rl.on('line', (input) => {
  processLine(input);
});

-download.js

const cassandra = require('cassandra-driver');
var iconv = require('iconv-lite');

const readline = require('readline');
const fs = require('fs');
const zlib = require('zlib');

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

const client = new cassandra.Client({ contactPoints: ['10.69.72.113','10.69.72.114','10.69.72.115','10.69.72.116','10.69.72.117'], keyspace: 'micapsdataserver' });
client.connect(function (err) {
  if (err) return console.error(err);
  console.log('Connected to cluster with %d host(s): %j', client.hosts.length, client.hosts.keys());
  
  //console.log(client.metadata);//.keyspaces.micapsdataserver.tables
});


const processLine = (line)=>{
	//const query = 'SELECT cql_version FROM system.local';
	const query = line;
	const result = client.execute(query, function (err, result) {
	  if (err) return console.error(err);
	  
	  if(! result.rows) return console.log("execute finished(完成)!");
	  console.log(result.rows.length);
	  for(let val of result.rows){
	  
		let content =  val.value;
		if(val.column1 && content){
			zlib.gunzip(content, (err, buffer) => {
				if ( err ) throw err;
				 
				content = buffer;
			
			/*  //Micaps4 网络数据存储及传输格式
				console.log(`data ${Buffer.isBuffer(content) ? 'is' : 'is not'} Buffer`);
				console.log( content );
				console.log('utf8 ' + iconv.decode(content, 'utf8').slice(0,1000));
				console.log('ascii ' + iconv.decode(content, 'ascii').slice(0,1000));
				console.log('utf16 ' + iconv.decode(content, 'utf16').slice(0,1000));
				console.log('GB2312 ' + iconv.decode(content, 'GB2312').slice(0,1000));
				console.log('GBK ' + iconv.decode(content, 'GBK').slice(0,1000));
				console.log('hex ' + iconv.decode(content, 'hex').slice(0,1000));
			*/	
				
				console.log(`writing data to file ${val.column1}...`);
				
				fs.writeFile(val.column1, content, (err) => {
				  if (err) throw err;
				  
				  console.log(`The file ${val.column1} has been saved!`);

				});
			
			});
		}else console.log(val);
		
	  }
	});
}

rl.on('line', (input) => {
  processLine(input);
});

list-all-dataPath.js

const cassandra = require('cassandra-driver');

const readline = require('readline');

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

const client = new cassandra.Client({ contactPoints: ['10.69.72.113'], keyspace: 'micapsdataserver' });
client.connect(function (err) {
  if (err) return console.error(err);
  console.log('Connected to cluster with %d host(s): %j', client.hosts.length, client.hosts.keys());
  
  //console.log(client.metadata.keyspaces);
});


const queryNext = (tablename, dataPath)=>{

	const query = `select "dataPath",column1 from "${tablename}" where token("dataPath")> token('${dataPath}') limit 1`;
	const result = client.execute(query, function (err, result) {
	  if (err) return console.error(err);
	  
	  if(! result.rows) return console.log("execute finished!");
	  console.log(result.rows.length);
	  for(let val of result.rows){
		console.log(val);
		
		queryNext(tablename, val.dataPath);//loop
	  }
	});
	
}

const processLine = (tablename)=>{
	const query = `SELECT * FROM "${tablename}" limit 1`;
	const result = client.execute(query, function (err, result) {
	  if (err) return console.error(err);
	  
	  if(! result.rows) return console.log("execute finished!");
	  console.log(result.rows.length);
	  for(let val of result.rows){
		console.log(val);
		queryNext(tablename, val.dataPath);//loop
	  }
	});
}

rl.on('line', (input) => {
  processLine(input);
});