环境介绍三台CentOS7主机192.168.122.101hdfs1192.168.122.102hdfs2192.168.122.103hdfs3其中hdfs1为主节点，其他为从节点。三台机器的安装配置都是一样的。做ssh免密码认证。如果只需要对master节点hdfs1进行操作，那么只需要信任来自hdfs1的其他节点即可。如果所有三个平台都相互信任，那么在其中任何一个平台上都是一样的。修改内核参数vim/etc/sysctl.confnet.ipv4.tcp_syn_retries=1net.ipv4.tcp_synack_retries=1net.ipv4.tcp_keepalive_time=600net.ipv4.tcp_keepalive_probes=3net.ipv4.tcp_keepalive_intvl=15net.ipv4.tcp.tcp_keepalive_time=tcp_timep2net.ipv4.tcp_max_tw_buckets=65536net.ipv4.tcp_tw_recycle=1net.ipv4.tcp_tw_reuse=1net.ipv4.tcp_max_orphans=32768net.ipv4.tcp_syncookies=1net.ipv4.tcp_max_syn_backlog=16384net.ipv4.tcp_wmem=819213107216777216net.ipv4.tcp_rmem=3276813107216777216net.ipv4.tcp_mem=78643210485761572864net.ipv4.ip_local_port_range=102465000net.ipv4.ip_conntrack_max=65536net.ipv4.netfilter.ip_conntrack_max=65536net.ipv4.netfilter.ip_conntrack_tcp_timeout_established=180net.core.somaxconn=16384net.core.netdev_max_backlog=16384vm.max_map_count=262144Modify句柄限制vim/etc/security/limits.conf*softnoproc655♂*hardnoproc655360*softnofile655360*hardnofile655360设置不同节点上的主机名解析，设置对应的主机名hostnamectlset-hostnamehdfs1addhosts记录也可以使用dns解析，更加灵活。vim/etc/hosts192.168.122.101hdfs1192.168.122.102hdfs2192.168.122.103hdfs3创建用户和目录useraddhadooppasswdhadoopmkdir-p/apps/mkdir-pv/data/hdfs/hadoopmkdir-pv/database/data.hdoofownhadospassword-freesu-hadoopssh-keygenssh-copy-idhadoop@hdfs1ssh-copy-idhadoop@hdfs1ssh-copy-idhadoop@hdfs1ssh-keygen生成密钥的时候，一直回车完成ssh-copy-id的创建，需要的时候输入hadoop密码下载jdk下载地址：www.oracle.com/java/technologies/javase/javase-jdk8-downloads.html需要登录才能下载tarzxvfjdk-8u271-linux-x64.tar.gzmvjdk-8u271-linux-x64/apps/cd/apps/ln-sjdk1.8.0_271jdkcd-ifgrep'#modifybyscript'/etc/profile>>/dev/null2>&1;thenecho"alreadsetJAVA_HOME"elsecp/etc/profile/etc/profile_bak$(date+%Y%m%d%H%M%S)cat>>/etc/profile<
