军哥高质量微信群招人~

见字如面,我是军哥!

各位,周一好呀,又是美好的一天呀!

话说这几天又来了一大波读者,有朋友说加我微信提示繁忙,所以必须给解决一下撒!

我的朋友圈会发一些公号之外的感悟,比如读者问题问卷调查、趣味抽奖,说实话还挺好玩的!

另外,军哥的读者群已经开到第 13 群了,马上要建 14 群了~

欢迎我的读者(你)加入,这里有很多一线、二线公司技术、产品、技术管理大佬,你可以提各种技术、产品、管理、认知等问题,另外还有每日话题讨论,大家一起学习!我们抱团取暖,一起度过 2021 了。同时对于你提的问题,军哥也会根据情况回答你,我相信这样高质量的交流群,一定可以助你高速成长!

不过要申明的是,群里拒绝发广告,如果你实在想发也行,发红包就行了!

好了,就说这么多了。如果你想进这样的高质量读者群,加我下方微信备注 38,请一定简单介绍下自己哈,我拉你入群(已经进了其他读者群,就不要申请了)!如加不上,请手动添加vx:jeff_cheng02

cf72b3e5eeb6629bab039726b052bf86.png

### Hadoop High Availability Configuration In a typical Hadoop setup, NameNode plays a critical role in managing metadata operations for the file system. However, this single point of failure can lead to downtime during planned maintenance or unexpected crashes. To address these issues, Hadoop offers high availability features that ensure continuous operation. #### Active/Standby NameNodes The core concept involves setting up two NameNodes within the same cluster—one active and one standby—to provide redundancy[^1]. The active node handles all client requests while the standby remains synchronized but does not serve any external traffic until it becomes necessary due to failover conditions. To configure HA: - **Journal Nodes**: These nodes maintain edits logs shared between primary and secondary NameNodes ensuring consistency across them. ```bash hdfs namenode -format ``` - **ZooKeeper Failover Controller (ZKFC)**: Each NN runs an instance which communicates through Zookeeper quorum deciding when to trigger automatic failovers based on health checks performed periodically by ZKFCs themselves. Configuration parameters include `dfs.nameservices`, specifying logical nameservice ID; `dfs.ha.namenodes.[nameserviceID]` listing IDs assigned uniquely per pair of NNS involved etc., found under `/etc/hadoop/conf/core-site.xml`. For example: ```xml <property> <name>dfs.nameservices</name> <value>mycluster</value> </property> <property> <name>dfs.ha.namenodes.mycluster</name> <value>nn1,nn2</value> </property> ``` Additionally, adjusting ports might also become essential depending upon existing services running alongside like changing webserver_port from default value if required as mentioned previously regarding BE component installation scenarios where adjustments were made accordingly. --related questions-- 1. How do JournalNodes contribute towards maintaining synchronization among multiple NameNodes? 2. What mechanisms are employed by ZooKeeper Failover Controllers during automated failover processes? 3. Can you elaborate further on how specific configuration files should be modified for enabling HA support effectively? 4. In what situations would altering port settings prove beneficial beyond just avoiding conflicts with other applications? 5. Are there additional considerations outside traditional configurations needed specifically for securing highly available clusters against potential threats?
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值