HBase Plugin

hbase::connect

Syntax

hbase::connect(host, port, [isFramed], [timeout])

Arguments

• host: STRING. The server address to connect to.

• port: INT. The port number of the Thrift server.

• isFramed: BOOL, default False. Whether to transport using TBufferedTransport (default) or TFramedTransport (true).

• timeout: INT, default 5000ms. The maximum time for connection and a receive call to wait before timeout.

Details

Build a connection to HBase via Thrift server and return an HBase handle.

Examples

conn = hbase::connect("192.168.1.114",9090)

Note: If the connection remains inactive for a while (1min by default), HBase will automatically close it. If you try to operate through this connection, the No more data to read error will be reported. In such case, you have to execute hbase::connect to reconnect.

You can configure with hbase.thrift.server.socket.read.timeout and hbase.thrift.connection.max-idletime to change the timeout.

<property>
         <name>hbase.thrift.server.socket.read.timeout</name>
         <value>86400000</value>
         <description>eg:milisecond</description>
</property>

<property>
         <name>hbase.thrift.connection.max-idletime</name>
         <value>86400000</value>
</property>

hbase::showTables

Syntax

hbase::showTables(hbaseConnection)

Arguments

• hbaseConnection: The handle returned by hbase::connect.

Details

Return all table names of the connected database.

conn = hbase::connect("192.168.1.114", 9090)
hbase::showTables(conn)

hbase::deleteTable

Syntax

hbase::deleteTable(hbaseConnection, tableName)

Arguments

• hbaseConnection: The handle returned by hbase::connect.

• tableName: STRING or STRING vector. The name of the table to be deleted.

Details

Delete tables in the database.

conn = hbase::connect("192.168.1.114", 9090)
hbase::deleteTable(conn, "demo_table")

hbase::getRow

Syntax

hbase::getRow(hbaseConnection, tableName, rowKey, [columnName])

Arguments

• hbaseConnection: The handle returned by hbase::connect.

• tableName: STRING. The name of the table to be read.

• rowKey: STRING. The index of the row to be read.

• columnName: STRING or STRING vector. The name of the column to be read. If not specified, all columns are read by default.

Details

Return the specific record with rowKey.

conn = hbase::connect("192.168.1.114", 9090)
hbase::getRow(conn, "test", "row1")

hbase::load

Syntax

hbase::load(hbaseConnection, tableName, [schema])

Arguments

• hbaseConnection: The handle returned by hbase::connect.

• tableName: STRING. The name of the table to be loaded.

• schema: optional. If specified, it is a table containing names of the columns to be imported and their data types. The column names speicified in schema must be consistent with the HBase column names. If not specified, the table will be created based on the first row with each column of STRING type. Note that each row must have the same size.

Details

Import the HBase results into a DolphinDB in-memory table. The data types supported for schema are described in chapter 3.

Examples

conn = hbase::connect("192.168.1.114", 9090)
t =  table(["cf:a","cf:b", "cf:c", "cf:time"] as name, ["STRING", "INT", "FLOAT", "TIMESTAMP"] as type)
t1 = hbase::load(conn, "test", t)

Use Precompiled Package

You can use the pre-built binaries libPluginOPCUA.so.

(1) Add the plugin path to the library search path LD_LIBRARY_PATH

export LD_LIBRARY_PATH=path_to_hbase_plugin/:$LD_LIBRARY_PATH

loadPlugin("path_to_hbase_plugin/PluginHBase.txt")

Compile from Source

You can also manually compile an HBase plugin with CMake on Linux following the instructions:

sudo apt-get install cmake

sudo apt-get install openssl

mkdir build
cd build
cmake ../
make