August 2015
Intermediate to advanced
312 pages
7h 28m
Japanese
Content preview from 初めてのSpark
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
213
10.6 常時稼働の運用
マスターを
local
あるいは
local[1]
に設定した状態で、Spark Streaming のプログラムをローカ
ル実行してはいけません。そうした場合、タスクには 1 つの CPU だけが割り当てられるので、レ
シーバがマスター上で動作すると、受信したデータを処理するリソースが残らないことになります。
コア数を増やすために、最低でも
local[2]
としてください。
10.6
時の
Spark Streaming
の主なメリットは、強固なフォールトトレランスが保証されることです。入力
データが信頼性を持って保存されるなら、
Spark Streaming
は厳密に
1
度限りのセマンティクスの
下で、仮にワーカーやドライバに障害があったとしても、常に正しい結果を計算できます（すなわ
ち、すべてのデータはいずれのノードにも障害がなかったかのように処理されます）。
Spark Streaming
のアプリケーションを常時稼働させるためには、多少特殊なセットアップが
必要になります。最初のステップは、
HDFS
や
Amazon S3
†
のような信頼性のあるストレージシ
ステムへのをセットアップすることです。加えて、ドライバプログラムの
フォールトトレランス（これには特殊なセットアップのコードが必要になります）や、信頼性の低
い入力ソースについても配慮が必要になります。本セクションでは、これらのセットアップの方法
を採り上げます。
10.6.1
ックイント理
チェックポイント処理は、 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.