There are various ways to access and interact with Apache HBase. The Java API provides the most functionality.
If users want to use HBase without Java, there are two main approaches for doing that: One is the Thrift interface, the other way to access HBase is using the REST interface.
This extension is a HBase REST Client Library for Tcl. The library consists of a single Tcl Module file.
HBaseClient is using Tcl built-in package http to send request to Apache HBase REST server and get response.
I only test this extension on Apache HBase standalone mode (Apache HBase 1.1.5 and Zookeeper 3.4.8, no security settings).
User needs to start Aapache HBase REST Server daemon.
This extension needs Tcl 8.6, tdom and tcllib base64 package.
The library has 1 TclOO class, HBaseClient.
Get HBase version:
package require HBaseClient
set myhbase [HBaseClient new http://localhost:8080]
$myhbase version
List current tables, now the list is empty:
$myhbase listTable
Then create a table:
$myhbase createTable "test" "cf"
List current tables:
$myhbase listTable
Put some values to test:
$myhbase putValue "test" "row1" "cf" "a" "value1"
$myhbase putValue "test" "row2" "cf" "b" "value2"
$myhbase putValue "test" "row3" "cf" "c" "value3"
Do a stateless scan for our table:
$myhbase scanRow "test"
Get the values:
$myhbase getValue "test" "row1"
$myhbase getValue "test" "row2"
$myhbase getValue "test" "row3"
Or more detail parameters:
$myhbase getValue "test" "row1" "cf" "a"
Try to delete a value:
$myhbase deleteValue "test" "row1" "cf" "a"
Or you can try to delete more values (delete an entire row):
$myhbase deleteValue "test" "row1"
OK, now query again:
$myhbase getValue "test" "row1"
User should get "Not found" response. In the last step, drop the table:
$myhbase deleteTable "test"
If user enables HTTPS support, below is an example:
package require HBaseClient
set myhbase [HBaseClient new https://localhost:8080 1]
Please notice, I use TLS extension to add https support. So https support needs TLS extension.