HBase client using the REST connector
npm install hbase2
Node HBase is a Node.JS client for the Apache HBase database. It use the Rest
API (Stargate) to communicate with HBase. Currently, all the API is implemented
and the data exchange format is JSON (but protocol buffer could follow).
Apache HBase is part of the Hadoop ecosystem. It describes itself as the Hadoop
database optimized for random, realtime read/write access to big data. It is an
open-source, distributed, versioned, column-oriented store modeled after Google
Bigtable.
Client features include:
* Intuitive API following HBase naming conventions
* Documentation and tests
* Full Implementation of the REST API
* Transparent encoding/decoding of values
* Scanner and filter support implementing the stream.Readable API
* Kerberos Support
bash
npm install hbase
`
Quick example
This code create a new HBase instance, create a table and a column family,
insert a few records and traverse them.
`javascript
var assert = require('assert');
var hbase = require('hbase');
hbase({ host: '127.0.0.1', port: 8080 })
.table('my_table' )
.create('my_column_family', function(err, success){
this
.row('my_row')
.put('my_column_family:my_column', 'my value', function(err, success){
this.get('my_column_family', function(err, cells){
this.exists(function(err, exists){
assert.ok(exists);
});
});
});
});
`
Using Kerberos/SPNEGO
Options accepts a krb5 object. Password and keytab authentication are supported.
Refer to the [krb5] package for additionnal information on how to configure the
krb5 option.
Using a keytab:
`
var hbase = require('hbase');
hbase({
host: '127.0.0.1',
port: 8080,
"krb5": {
"principal": "{username}@{REALM}",
"keytab": "{path/to/keytab}",
"service_principal": "HTTP@{fqdn}"
}
})
.version();
`
Using a password:
`
var hbase = require('hbase');
hbase({
host: '127.0.0.1',
port: 8080,
"krb5": {
"principal": "{username}@{REALM}",
"password": "{password}",
"service_principal": "HTTP@{fqdn}"
}
})
.version();
`
Scanner and Filters
The scanner implement the stream.Readable API. For ease of usage, an optional
callback argument may be provided. For example:
`bash
client
.table('node_table')
.scan({
startRow: 'my_row',
maxVersions: 1
}, function(err, rows){
console.log(err, rows);
});
`
is equivalent to:
`coffee
var rows = [];
scanner = client
.table('node_table')
.scan({
startRow: 'my_row',
maxVersions: 1
});
scanner.on('readable', function(){
while(chunk = scanner.read()){
rows.push(chunk);
}
});
scanner.on('error', function(err){
console.log(err);
});
scanner.on('end', function(){
console.log(rows);
});
`
It can be quite a pain to figure out what options can be sent
with a scanner request. You will find a lot of examples inside the
[Scanner test][scanner] and also look at the [examples][mt_samples] published by
[Marc Trudel][mt_home].
Running the tests
Tests are executed with mocha. Before running the tests the first time, copy the
file "./test/properties.json.sample" to "./test/properties.json" and make the
appropriate changes.
If using the HDP sandbox, start the virtual machine, log-in as "root", start
Ambari start_ambari.sh, start HBase start_hbase.sh and start the HBase REST
server /usr/lib/hbase/bin/hbase rest -p 60080.
Otherwise you can run HBase in locally with
docker run --name stargate --rm -p 60080:8080 sixeyed/hbase-stargate
docker run --name stargate -p 2181:2181 -p 60010:60010 -p 60000:60000 -p 60020:60020 -p 60030:60030 -p 60080:8080 -p 8085:8085 sixeyed/hbase-stargate
To run the tests:
`bash
make test
`
There is also a Dockerfile under hbase-rest-reverse-proxy/ that creates an Nginx reverse proxy to HBase REST. This image can be used to test cases where the REST service runs behind a proxy. The file test/properties_with_path.docker.coffee can be used to test scenarios where HBase REST is accessible through a custom path (/rest).
When testing against HBase secured with Kerberos, you must create a table with
the right ownership.
`bash
kinit hbase
hbase shell
create 'node_table', {NAME => 'node_column_family', VERSIONS => 5}
grant 'ryba', 'RWC', 'node_table'
``