May 2017
Intermediate to advanced
348 pages
7h 8m
English
Content preview from Hadoop 2.x Administration CookbookBecome 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,
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Initiating Namenode saveNamespace
In our earlier recipes, we have configured the Hadoop cluster and have gone through various concepts on cluster operations. We saw that Namenode stores the metadata, which is a combination of the fsimage file and edits file and these two images are never merged by Namenode, unless it is restarted or there is some other node, such as Secondary Namenode, which does this. We will be covering Secondary Namenode in this chapter at a later stage.
Whenever the Namenode is started, it applies all the changes in the edits file to the fsimage file and starts with a clean edits file. Depending upon the size of the edits log, it could take a long time to start up Namenode and this adds to the total time a Namenode stays in ...
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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.