hadoop - Name Node 同时作为 Secondary Name Node 是否理想？

Question

我正在通过 Raspberry Pi 练习 hadoop 集群，根据本教程(http://www.widriksson.com/raspberry-pi-hadoop-cluster/)，他在 hadoop masters 文件配置中设置了 node1，这令人困惑，因为他还使用节点启动 hadoop 守护进程。我也想知道他配置的原因

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Answer 1

不，这并不理想。如何配置集群取决于您。在本教程中，作者决定同时使用 node1 作为 P-NN 和 S-NN。请记住，RPi Hadoop 集群仅适用于开发和测试，而不适用于生产环境。

在单独的机器上运行主 NameNode 和辅助 NameNode 的优缺点(基于 Cloudera 的 This article):

1.Scalability. Creating the system snapshot requires about as much memory as the NameNode itself occupies. Since the memory available to the NameNode process is a primary limit on the size of the distributed filesystem, a large-scale cluster will require most or all of the available memory for the NameNode.

2.Durability. When the SecondaryNameNode creates a checkpoint, it does so in a separate copy of the filesystem metadata. Moving this process to another machine also creates a copy of the metadata file on an independent machine, increasing its durability.