centos 7.5下安装 elasticsearch 启动的问题

￡神魔★判官ぃ 2022-05-15 02:51 206阅读 0赞

# centos7.5下安装 elasticsearch 启动的问题 #

安装elasticsearch正常步骤

1.  Download and unzip Elasticsearch
2.  Run bin/elasticsearch 
3.   Run curl http://localhost:9200/

异常信息：

root 账户启动报错，Exception in thread "main" [Java][].lang.RuntimeException: don't run elasticsearch as root.

解决办法：

**解决方法1：**

在执行elasticSearch时加上参数-Des.insecure.allow.root=true，完整命令如下

1.  ./elasticsearch -Des.insecure.allow.root=true

**解决办法2：**

用vi打开elasicsearch执行文件，在变量ES\_JAVA\_OPTS使用前添加以下命令

1.  ES\_JAVA\_OPTS="-Des.insecure.allow.root=true"

**解决办法3（建议使用此方法）：**

添加新用户组和用户，让非root 用户组用户启动：

groupadd elasticsearch

useradd es -g elasticsearch -p 123456

然后把我们的es 所在文件夹的 用户指定为 elsearch

chown -R es:elasticsearch /opt/elasticsearch

启动成功之后 会有日志：

[2016-12-20T18:40:28,270][INFO ][o.e.g.GatewayService     ] [MUQhN6Y] recovered [0] indices into cluster_state
    [2016-12-20T18:40:28,276][INFO ][o.e.h.HttpServer         ] [MUQhN6Y] publish_address {127.0.0.1:9200}, bound_addresses {[::1]:9200}, {127.0.0.1:9200}
    [2016-12-20T18:40:28,276][INFO ][o.e.n.Node               ] [MUQhN6Y] started

访问url 成功会有结果：

{
      "name" : "MUQhN6Y",
      "cluster_name" : "elasticsearch",
      "cluster_uuid" : "GQd_A6XCRFKMnzswmckmuA",
      "version" : {
        "number" : "5.1.1",
        "build_hash" : "5395e21",
        "build_date" : "2016-12-06T12:36:15.409Z",
        "build_snapshot" : false,
        "lucene_version" : "6.3.0"
      },
      "tagline" : "You Know, for Search"
    }

现在本机访问可以访问了，但是在其他机器上访问还是有问题，提示连接拒绝,为什么呢？

因为这个端口只是监听127.0.0.1 的回环地址，不监听其他地址，而127 的地址只能本机访问，所以其他机器无法访问这台机器。

那该怎么办呢？

es 提供了解决办法：

/opt/elasticsearch-2.4.6/config 目录下有一个 文件elasticsearch.yml

如果想监听本机所有ip ,则配置：network.host: 192.168.1.146

如果想监听指定ip，多个ip逗号隔开 则：network.host: 127.0.0.1,192.168.12.18

然后重新启动，爆出异常：

max file descriptors [4096] for elasticsearch process likely too low, increase to at least [65536]
    
    vm.max_map_count [65530] likely too low, increase to at least [262144]

第一个问题：解决方案：

同样回到config/elasticsearch.yml文件，找到如下配置，开放discovery.zen.ping.unicast.hosts及discovery.zen.minimum\_master\_nodes

# --------------------------------- Discovery ----------------------------------
    
    #
    
    # Pass an initial list of hosts to perform discovery when new node is started:
    
    # The default list of hosts is ["127.0.0.1", "[::1]"]
    
    #
    
    discovery.zen.ping.unicast.hosts: ["192.168.0.155"]
    
    #
    
    # Prevent the "split brain" by configuring the majority of nodes (total number of nodes / 2 + 1):
    
    #
    
    discovery.zen.minimum_master_nodes: 3
    
    #
    
    # For more information, see the documentation at:
    
    # <http://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery.html>

然后修改max file descriptors \[4096\] for elasticsearch process likely too low, increase to at least \[65536\]这个错误（切换到root操作）

切换到root 用户 ：

[root@localhost ~]# cp /etc/security/limits.conf /etc/security/limits.conf.bak
    
    [root@localhost ~]# cat /etc/security/limits.conf | grep -v "seven" > /tmp/system_limits.conf
    
    [root@localhost ~]# echo "seven hard nofile 65536" >> /tmp/system_limits.conf
    
    [root@localhost ~]# echo "seven soft nofile 65536" >> /tmp/system_limits.conf
    
    [root@localhost ~]# mv /tmp/system_limits.conf /etc/security/limits.conf

以上serven 名称为 自己的非root 用户名。

修改后重新登录seven用户，使用如下命令查看是否修改成功

[seven@localhost ~]$ ulimit -Hn
    
    65536

第2个问题：解决方案：

[root@localhost ~]# cat /etc/sysctl.conf | grep -v "vm.max_map_count" > /tmp/system_sysctl.conf
    
        [root@localhost ~]# echo "vm.max_map_count=262144" >> /tmp/system_sysctl.conf
    
        [root@localhost ~]# mv /tmp/system_sysctl.conf /etc/sysctl.conf
    
        mv：是否覆盖"/etc/sysctl.conf"？ y
    
        [root@localhost ~]# cat /etc/sysctl.conf
    
        # System default settings live in /usr/lib/sysctl.d/00-system.conf.
    
        # To override those settings, enter new settings here, or in an /etc/sysctl.d/<name>.conf file
    
        #
    
        # For more information, see sysctl.conf(5) and sysctl.d(5).
    
        vm.max_map_count=262144
    
        [root@localhost ~]# sysctl -p
    
        vm.max_map_count = 262144

上面还有一个错误是关于jvm内存分配的问题heap size \[268435456\] not equal to maximum heap size \[2147483648\]，需要修改的jvm配置

[seven@localhost bin]$ vim /usr/java/elasticsearch/config/jvm.options

将-Xmx2g改成-Xmx256m，也就是heap size \[268435456\] /1024/1024的值

又爆出第三个问题：max number of threads \[1024\] for user \[lish\] likely too low, increase to at least \[2048\]

解决方案：

# vi /etc/security/limits.d/90-nproc.conf 
    # Default limit for number of user‘s processes to prevent
    # accidental fork bombs. 
    # See rhbz #432903 for reasoning. * soft nproc 1024 root soft nproc unlimited

修改1024 为2048 。

最后终于启动成功，并且其他机器也可以访问了

[Java]: http://lib.csdn.net/base/javase