现象一
ES使用root用户安装报错如下
Caused by: java.lang.RuntimeException: can not run elasticsearch as root
代码语言：javascript复制[root@localhost elasticsearch-7.14.2]# ./bin/elasticsearch
[2022-09-18T16:40:41,166][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [localhost.localdomain] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:163) ~[elasticsearch-7.14.2.jar:7.14.2]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150) ~[elasticsearch-7.14.2.jar:7.14.2]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:75) ~[elasticsearch-7.14.2.jar:7.14.2]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:116) ~[elasticsearch-cli-7.14.2.jar:7.14.2]
at org.elasticsearch.cli.Command.main(Command.java:79) ~[elasticsearch-cli-7.14.2.jar:7.14.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115) ~[elasticsearch-7.14.2.jar:7.14.2]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:81) ~[elasticsearch-7.14.2.jar:7.14.2]
Caused by: java.lang.RuntimeException: can not run elasticsearch as root
at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:103) ~[elasticsearch-7.14.2.jar:7.14.2]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:170) ~[elasticsearch-7.14.2.jar:7.14.2]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:399) ~[elasticsearch-7.14.2.jar:7.14.2]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159) ~[elasticsearch-7.14.2.jar:7.14.2]
... 6 more
uncaught exception in thread [main]
java.lang.RuntimeException: can not run elasticsearch as root
at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:103)
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:170)
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:399)
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:159)
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:150)
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:75)
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:116)
at org.elasticsearch.cli.Command.main(Command.java:79)
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:115)
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:81)
For complete error details, refer to the log at /opt/ES/elasticsearch-7.14.2/logs/elasticsearch.log解决方法
ES官方为了安全起见，禁止启用Root启动ES服务，因此我们需要进行普通用户的创建，才能正常启动ES服务。所以我们需要新建一个普通用户，并将ES安装目录授权给刚新建的用户。
代码语言：javascript复制[root@localhost ES]# useradd Elastic
[root@localhost ES]# chown -R Elastic:Elastic /opt/ES/elasticsearch-7.14.2现象二
因为 es 不允许使用root用户安装，在使用新建的es用户安装的时候报错如下，
max file descriptors 4096 for elasticsearch process is too low, increase to at least 65535
代码语言：javascript复制[2022-09-18T16:58:23,719][INFO ][o.e.t.TransportService ] [localhost.localdomain] publish_address {192.168.239.134:9300}, bound_addresses {192.168.239.134:9300}
[2022-09-18T16:58:23,805][INFO ][o.e.b.BootstrapChecks ] [localhost.localdomain] bound or publishing to a non-loopback address, enforcing bootstrap checks
ERROR: [2] bootstrap checks failed. You must address the points described in the following [2] lines before starting Elasticsearch.
bootstrap check failure [1] of [2]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]
bootstrap check failure [2] of [2]: 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
ERROR: Elasticsearch did not exit normally - check the logs at /opt/ES/elasticsearch-7.14.2/logs/elasticsearch.log解决办法
将当前用户的软硬限制调大。找到文件 /etc/security/limits.conf，编辑，在文件的最后追加如下配置：
文件描述符现象三
默认发现设置不适合生产使用；必须至少配置一个discovery.seed_hosts、discovery.seed_providers、cluster.initial_master_nodes
代码语言：javascript复制[2022-09-18T17:23:09,988][INFO ][o.e.t.TransportService ] [localhost.localdomain] publish_address {192.168.239.134:9300}, bound_addresses {192.168.239.134:9300}
[2022-09-18T17:23:10,086][INFO ][o.e.b.BootstrapChecks ] [localhost.localdomain] bound or publishing to a non-loopback address, enforcing bootstrap checks
ERROR: [1] bootstrap checks failed. You must address the points described in the following [1] lines before starting Elasticsearch.
bootstrap check failure [1] of [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
ERROR: Elasticsearch did not exit normally - check the logs at /opt/ES/elasticsearch-7.14.2/logs/elasticsearch.log解决办法
修改elasticsearch.yml将discovery.seed_hosts: "node-1"改为主机名
代码语言：javascript复制# --------------------------------- 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: ["node-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.
