May 2019
Intermediate to advanced
464 pages
9h 22m
Japanese
Content preview from Node.jsデザインパターン 第2版
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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.
11.1
メッセージ通信システムの基礎
377
話を使うか、話している通話を切って新たに通話を始める必要があります。
非同期通信は
SMS
に似ています。メッセージの送信時に受信者がネットワークに接続している必要
はなく、応答はすぐに受信する場合もあれば不定時間後に受信する場合もあり、あるいは全く受信し
ない場合もあります。複数のメッセージを複数の受信者に順次送信することも、応答（ある場合）をそ
の順序に関係なく受信することもあります。要するに、少ないリソースで並行処理がうまくできるとい
うわけです。
非同期通信のもうひとつの重要な利点は、メッセージをいったん保管して、できるだけ早く配信する
ことも後で配信することもできることです。これは受け手が忙しくて新しいメッセージを処理できない
場合や配信を保証したい場合に便利です。メッセージシステムでは、「メッセージキュー」を使ってこ
れを実現できます。これは送り手と受け手の間
で通信を仲介するコンポーネントで、すべてのメッセー
ジを宛先に配信する前に保管します（図11-4）。
送り手 受け手
メッセージキュー
図11-4 メッセージキューの利用
何らかの理由で受け手に異常終了やネットワークからの切断、あるいは処理速度の低下が起きると、
メッセージはキューに蓄積され、受け手がオンラインに復旧し完全稼働すると即時に配信されます。
キューは送り手側に置くことも、送り手と受け手に分割しておくことも、さらには通信用ミドルウェア
として働く外部の専用システムにおくこともできます。
11.
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
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.