linux使用yum下安装elasticsearch 7.17.6-1

1. 首先确定linux系统中yum环境是正常的

2. 在/etc/yum.repos.d/ 或者/etc/zypp/repos.d/ 目录下创建一个名为elasticsearch.repo的文件（自己进去看一下，有那个文件夹就在那个文件夹下创建）

   文件内容:

   [elasticsearch]
   name=Elasticsearch repository for 7.x packages
   baseurl=https://artifacts.elastic.co/packages/7.x/yum
   gpgcheck=1
   gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
   enabled=0
   autorefresh=1
   type=rpm-md
   

3. 使用 yum list elasticsearch 或者 yum search elasticsearch --showduplicates 查看可用版本

   [root@iZ25hep58miZ yum.repos.d]# yum list elasticsearch
   Loaded plugins: fastestmirror
   Loading mirror speeds from cached hostfile
   Installed Packages
   elasticsearch.x86_64                                             7.17.6-1                  
   [root@iZ25hep58miZ yum.repos.d]# yum search elasticsearch --showduplicates
   Loaded plugins: fastestmirror
   Loading mirror speeds from cached hostfile
   ==================================================== N/S Matched: elasticsearch ===========
   elasticsearch-7.17.6-1.x86_64 : Distributed RESTful search engine built for the cloud
   
     Name and summary matches only, use "search all" for everything.
   

4. 如果不要求指定版本 , 执行 yum install --enablerepo=elasticsearch elasticsearch 命令。等待安装完成。

5. 如果要指定版本则执行

   yum install --enablerepo=elasticsearch elasticsearch-7.17.6-1.x86_64 补充完整的版本号

6. 接下来可执行启动命令 service elasticsearch start , 会报一些错误

7. 内存不足问题 , 由于 elasticsearch 默认分配 jvm空间大小为2g，修改 jvm空间，如果Linux服务器本来配置就很高，可以不用修改

   error:
   OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000c6a00000, 962592768, 0) failed; error='Not enough space' (errno=12)
           at org.elasticsearch.tools.launchers.JvmOption.flagsFinal(JvmOption.java:119)
           at org.elasticsearch.tools.launchers.JvmOption.findFinalOptions(JvmOption.java:81)
           at org.elasticsearch.tools.launchers.JvmErgonomics.choose(JvmErgonomics.java:38)
           at org.elasticsearch.tools.launchers.JvmOptionsParser.jvmOptions(JvmOptionsParser.java:13
   

   cd /etc/elasticsearch/jvm.options.d vim jvm.options 依据服务器内容大小修改

   -Xms1G
   -Xmx1G
   

8. 修改ES核心配置信息

   执行命令修改elasticsearch.yml文件内容

   修改绑定的ip允许远程访问

   #默认只允许本机访问，修改为0.0.0.0后则可以远程访问
   # 绑定到0.0.0.0，允许任何ip来访问
   network.host: 0.0.0.0 
   

   初始化节点名称

   cluster.name: elasticsearch 
   node.name: es-node0
   cluster.initial_master_nodes: ["es-node0"]
   

9. elasticsearch用户的最大线程数太低

 max number of threads [1024] for user [elasticsearch] i
s too low, increase to at least [4096]

错误原因: elasticsearch用户的最大线程数太低 , 修改limits.d目录下的配置文件：

vi /etc/security/limits.d/90-nproc.conf

10. 这是在因为Centos6不支持SecComp，而ES5.2.0默认bootstrap.system_call_filter为true进行检测，所以导致检测失败，失败后直接导致ES不能启动。

    system call filters failed to install; check the logs a
    nd fix your configuration or disable system call filters at your own risk
    

    解决：
    在elasticsearch.yml中配置bootstrap.system_call_filter为false，注意要在Memory下面:

    bootstrap.memory_lock: false
    bootstrap.system_call_filter: false
    

11. 7.x使用x-pack

切换到elasticsearch的bin目录下，使用下列命令生成证书

./elasticsearch-certutil cert -out /etc/elasticsearch/elastic-certificates.p12 -pass ""

打开 /etc/elasticsearch/elasticsearch.yaml , 在尾部添加下边代码

xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.keystore.path: elastic-certificates.p12
xpack.security.transport.ssl.truststore.path: elastic-certificates.p12

第一行为开启密码访问 , 本意是只设置密码, 但是7.x版本要求开启密码后必须开启第二行ssl , 所以产生345行配置ssl证书的配置
bin目录下执行下面命令自动配置各用户密码 auto为自动, interactive为手动

 ./elasticsearch-setup-passwords auto

启动服务提示下面错误

uncaught exception in thread [main]
ElasticsearchSecurityException[failed to load SSL configuration [xpack.security.transport.s
sl]]; nested: ElasticsearchException[failed to initialize SSL TrustManager - not permitted to read truststore file [/etc/elasticsearch/elastic-certificates.p12]]; nested: AccessDeniedException[/etc/elasticsearch/elastic-certificates.p12];Likely root cause: java.nio.file.AccessDeniedException: /etc/elasticsearch/elastic-certific
ates.p12uncaught exception in thread [main]
ElasticsearchSecurityException[failed to load SSL configuration [xpack.security.transport.s
sl]]; nested: ElasticsearchException[failed to initialize SSL TrustManager - not permitted to read truststore file [/etc/elasticsearch/elastic-certificates.p12]]; nested: AccessDeniedException[/etc/elasticsearch/elastic-certificates.p12];Likely root cause: java.nio.file.AccessDeniedException: /etc/elasticsearch/elastic-certific
ates.p12

到/etc/elasticsearch/目录下查看生成的elastic-certificates.p12

-rw------- 1 root elasticsearch  3448 Nov  7 15:43 elastic-certificates.p12
-rw-rw---- 1 root elasticsearch   199 Nov  7 09:06 elasticsearch.keystore
-rw-rw---- 1 root elasticsearch  1042 Aug 23 19:10 elasticsearch-plugins.example.yml
-rw-rw---- 1 root elasticsearch  3724 Nov  7 15:45 elasticsearch.yml
-rw-rw---- 1 root elasticsearch  3329 Aug 23 19:10 jvm.options
drwxr-s--- 2 root elasticsearch  4096 Nov  7 09:11 jvm.options.d
-rw-rw---- 1 root elasticsearch 19304 Aug 23 19:10 log4j2.properties
-rw-rw---- 1 root elasticsearch   473 Aug 23 19:10 role_mapping.yml
-rw-rw---- 1 root elasticsearch   197 Aug 23 19:10 roles.yml
-rw-rw---- 1 root elasticsearch     0 Aug 23 19:10 users
-rw-rw---- 1 root elasticsearch     0 Aug 23 19:10 users_roles

由第一行看出生成的elastic-certificates.p12 不属于elasticsearch用户组, 且没有读写权限 . 增加读写权限

chmod 664 elastic-certificates.p12

-rw-rw-r-- 1 root elasticsearch  3448 Nov  7 15:43 elastic-certificates.p12
-rw-rw---- 1 root elasticsearch   199 Nov  7 09:06 elasticsearch.keystore
-rw-rw---- 1 root elasticsearch  1042 Aug 23 19:10 elasticsearch-plugins.example.yml
-rw-rw---- 1 root elasticsearch  3724 Nov  7 15:45 elasticsearch.yml
-rw-rw---- 1 root elasticsearch  3329 Aug 23 19:10 jvm.options
drwxr-s--- 2 root elasticsearch  4096 Nov  7 09:11 jvm.options.d
-rw-rw---- 1 root elasticsearch 19304 Aug 23 19:10 log4j2.properties
-rw-rw---- 1 root elasticsearch   473 Aug 23 19:10 role_mapping.yml
-rw-rw---- 1 root elasticsearch   197 Aug 23 19:10 roles.yml
-rw-rw---- 1 root elasticsearch     0 Aug 23 19:10 users
-rw-rw---- 1 root elasticsearch     0 Aug 23 19:10 users_roles

第一组 rw-表示root用户有读写权限 , 第二组 rw-为给elasticsearch用户新增的读写权限,第三组表示其他用户的权限 , 此处设置4加了 r权限. 不加也可以

到此重启服务就可以了