{{{
#!html
hadoop + Hbase + thrift + php
程式碼解析
}}}
[[PageOutline]]
= 零、前言 =
* thrift 是透過非java的其他程式語言，直接對hbase 進行存取的中介函式庫
* ''''' 此篇介紹的是如何用php透過 thrift 對 hbase 操作 '''''
* 程式安裝測試方法已紀錄於： [wiki:waue/2010/0401 安裝編譯及測試 ]
* 因此目錄結構為
|| hadoop || /opt/hadoop ||
|| hbase || /opt/hbase ||
|| 網頁根目錄 || /var/www/ ||
|| hbase 的php碼目錄 || /var/www/hbase ||
|| thrift php || /var/www/hbase/thrift ||
* 測試程式之前，請先確定
* hbase , hadoop 都有正常運作中
* $ bin/hbase thrift start 尚在執行
= 一、php引用thrift lib =
{{{
#!php
setSendTimeout( 10000 ); // Ten seconds (too long for production, but this is just a demo ;)
$socket->setRecvTimeout( 20000 ); // Twenty seconds
$transport = new TBufferedTransport( $socket );
$protocol = new TBinaryProtocol( $transport );
$client = new HbaseClient( $protocol );
$transport->open();
?>
........
其他html 碼
.......
close();
?>
}}}
* 所有的程式碼都必須包含這些引入函式庫、開啟關閉socket 的敘述
= 二、各種對hbase的操作 =
== 2.1 列出hbase 裡的所有 table ==
{{{
#!php
getTableNames();
sort( $tables );
foreach ( $tables as $name ) {
echo( " found: {$name}\n" );
}
}
?>
}}}
== 2.2 刪除table ==
{{{
#!php
isTableEnabled( $name )) {
echo( " disabling table: {$name}\n");
$client->disableTable( $name );
}
echo( " deleting table: {$name}\n" );
$client->deleteTable( $name );
}
?>
}}}
== 2.3 新增table ==
* 我們先定義columns 的物件結構如下
{{{
#!php
'entry:',
'maxVersions' => 10
) ),
new ColumnDescriptor( array(
'name' => 'unused:'
) )
);
?>
}}}
* 將剛剛的column 放到table 內
{{{
#!php
createTable( $t, $columns );
} catch ( AlreadyExists $ae ) {
echo( "WARN: {$ae->message}\n" );
}
?>
}}}
== 2.4 列出 table內的家族成員 family ==
{{{
#!php
getColumnDescriptors( $t );
asort( $descriptors );
foreach ( $descriptors as $col ) {
echo( " column: {$col->name}, maxVer: {$col->maxVersions}\n" );
}
?>
}}}
== 2.5 寫入資料 ==
{{{
#!php
'entry:foo',
'value' => $valid
) ),
);
$client->mutateRow( $t, $row, $mutations );
?>
}}}
== 2.6 讀取資料 ==
=== get 取得一個 column value ===
* get 取得一個 column value 的用法
{{{
#!php
get($table_name, $row_name , $fam_col_name);
// $arr = array
foreach ( $arr as $k=>$v ) {
// $k = TCell
echo ("value = {$v->value} ,
");
echo ("timestamp = {$v->timestamp}
");
}
}
?>
}}}
=== getRow 取得一整個row ===
* getRow($tableName, $row) 用法
{{{
#!php
getRow($table_name, $row_name);
// $client->getRow return a array
foreach ( $arr as $k=>$TRowResult ) {
// $k = 0 ; non-use
// $TRowResult = TRowResult
printTRowResult($TRowResult);
}
?>
}}}
=== scan 一整個table ===
{{{
#!php
scannerOpen( $table_name, $start_row , $family );
// $scanner 是一個遞增數字 for open socket
// scannerGet() 一次只抓一row，因此要用while迴圈不斷地抓
while (true ){
$get_arr = $client->scannerGet( $scanner );
// get_arr is an array
if($get_arr == null) break;
// 沒有回傳值代表已經沒有資料可抓，跳脫此無限迴圈
foreach ( $get_arr as $TRowResult ){
// $TRowResult = TRowResult
echo (" row = {$TRowResult->row} ;
");
$column = $TRowResult->columns;
foreach ($column as $family_column=>$Tcell){
echo ("family:column = $family_column ");
// $family_column = family_column
// $Tcell = Tcell
echo (" value = {$Tcell->value} ");
echo (" timestamp = {$Tcell->timestamp}
");
}
}
}
echo( "
----------------- " );
echo( "
Scanner finished
" );
$client->scannerClose( $scanner );
?>
}}}
= 補充 =
== TCell ==
{{{
#!php
array(
'var' => 'value',
'type' => TType::STRING,
),
2 => array(
'var' => 'timestamp',
'type' => TType::I64,
),
);
}
if (is_array($vals)) {
if (isset($vals['value'])) {
$this->value = $vals['value'];
}
if (isset($vals['timestamp'])) {
$this->timestamp = $vals['timestamp'];
}
}
}
}
?>
}}}
== TRowResult ==
{{{
#!php
array(
'var' => 'row',
'type' => TType::STRING,
),
2 => array(
'var' => 'columns',
'type' => TType::MAP,
'ktype' => TType::STRING,
'vtype' => TType::STRUCT,
'key' => array(
'type' => TType::STRING,
),
'val' => array(
'type' => TType::STRUCT,
'class' => 'TCell',
),
),
);
}
if (is_array($vals)) {
if (isset($vals['row'])) {
$this->row = $vals['row'];
}
if (isset($vals['columns'])) {
$this->columns = $vals['columns'];
}
}
}
}
?>
}}}