目录
解压elasticsearch-7.6.2-linux-x86_64.tar.gz
?2.最大虚拟内存区域 vm.max_map_count [65530] 太低警告
3.启动异常：failed to obtain node locks
ubuntu安装 es7.6.2
- Ubuntu 18.04.4
- jdk （Ubuntu 18.04.4搭建开发环境之 JDK1.8安装，原先安装jdk8，后直接升级为jdk11版本，关于linux配置jdk1.8或者jdk11这里不再细说）
- elasticsearch-7.6.2
安装步骤
下载 ES （官网）
?在visit our downloads page中找到elasticsearch7.6.2版本，点击下载即可
上传至Ubuntu 服务器 这里我存放在 /usr/
解压elasticsearch-7.6.2-linux-x86_64.tar.gz
?解压后看下目录结构
bin 存放可执行的脚本文件目录
config 存放配置文件目录
data 存放node数据
jdk 版本自带jdk
logs 存放日志目录
plugins 用来扩展ES的插件目录这样就算基本完成了，先启动（一步一步踩坑开始）
root@daryl:/usr/elasticsearch-7.6.2# ./bin/elasticsearch &出现问题及解决方法
1.如启动时出现如下内容
java.lang.RuntimeException: can not run elasticsearch as root解决方法：此错误，是因为ES不能直接使用 Root 用户来启动，需要创建es用户，我这里直接创建的是esroot用户。
root@VM-0-2-ubuntu:/usr/local/elasticsearch-7.6.2# adduser esroot
Enter new UNIX password: ***** '输入你的密码'
Retype new UNIX password:***** '再次输入你的密码'
?enter 走下去，确认选 y 就 ok 了，然后再root用户下授权文件夹elasticsearch-7.6.2 权限给esroot用户。
root@daryl:/usr# chown -R esroot elasticsearch-7.6.2再切换到这个 esroot 用户 再次运行 ./bin/elasticsearch，后台启动则在启动命令后加 &
root@daryl:/usr# su esroot
esroot@daryl:/usr$ ./elasticsearch-7.6.2/bin/elasticsearch &
看到started之后，再使用curl命令查看，出现如下则为启动成功
?2.最大虚拟内存区域 vm.max_map_count [65530] 太低警告
[daryl] max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]解决方法：修改/etc/sysctl.conf文件，添加如下代码
? ? ?vm.max_map_count=262144
退出保存后执行如下命令:? ? sysctl -p
root@daryl:~# sysctl -p
vm.max_map_count = 655360
root@daryl:~#3.启动异常：failed to obtain node locks
[ERROR][o.e.b.Bootstrap ] [daryl] Exception
java.lang.IllegalStateException: failed to obtain node locks, tried [[/usr/elasticsearch-7.6.2/data]] with lock id [0]; maybe these locations are not writable or multiple nodes were started without increasing [node.max_local_storage_nodes] (was [1])?
at org.elasticsearch.env.NodeEnvironment.<init>(NodeEnvironment.java:301) ~[elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.node.Node.<init>(Node.java:277) ~[elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.node.Node.<init>(Node.java:257) ~[elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:221) ~[elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:221) ~[elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:349) [elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:170) [elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:161) [elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) [elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:125) [elasticsearch-cli-7.6.2.jar:7.6.2]
at org.elasticsearch.cli.Command.main(Command.java:90) [elasticsearch-cli-7.6.2.jar:7.6.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:126) [elasticsearch-7.6.2.jar:7.6.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) [elasticsearch-7.6.2.jar:7.6.2]解决方法：这类错误网上有很多解决方案，我们这边问题的原因则是第一次启动es是用root用户启动造成的。这时，只要删除/重命名data下的node目录，再次运行ES就可以解决
?4.启动后外网无法访问问题
netstat查看进程在运行状态，使用curl命令出现如下提示
esroot@daryl:/usr/elasticsearch-7.6.2$ curl 192.168.29.131:9200
curl: (7) Failed to connect to 192.168.29.131 port 9200: Connection refused解决方法：修改配置文件elasticsearch.yml，在network模块添加 network.host: 0.0.0.0
# ---------------------------------- Network -----------------------------------
#
# Set the bind address to a specific IP (IPv4 or IPv6):
#
#network.host: 192.168.0.1
network.host: 0.0.0.0
#
# Set a custom port for HTTP:
#
#http.port: 9200
#
# For more information, consult the network module documentation.
然后在Discovery模块添加?discovery.seed_hosts: ["127.0.0.1", "[::1]"]
# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
#discovery.seed_hosts: ["host1", "host2"]
discovery.seed_hosts: ["127.0.0.1", "[::1]"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
#cluster.initial_master_nodes: ["node-1", "node-2"]
#
# For more information, consult the discovery and cluster formation module documentation.
如果不添加的话启动会提示需要在discovery.seed_hosts,discovery.seed_providers, cluster.initial_master_nodes中至少设置一项的异常
[ERROR][o.e.b.Bootstrap ] [daryl] node validation exception
[1] bootstrap checks failed
[1]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured配置好之后，esroot用户下启动es用浏览器访问?http://192.168.29.131:9200/，ok
