Elasticsearch5.0 安装问题集锦

elasticsearch 5.0 安装过程中遇到了一些问题，通过查找资料几乎都解决掉了，这里简单记录一下 ，供以后查阅参考，也希望可以帮助遇到同样问题的你。

问题一：安装完elasticsearch后,运行报错

root@localhost work]# Exception in thread "main" Java.lang.UnsupportedClassVersionError: org/elasticsearch/bootstrap/Elasticsearch : Unsupported major.minor version 51.0

        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
        at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:323)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:268)
Could not find the main class: org.elasticsearch.bootstrap.Elasticsearch. Program will exit.

解决：1.在 /etc/profile相应位置添加Java环境变量(如果没有安装java运行环境则安装)

HOSTNAME=`/bin/hostname 2>/dev/null`
HISTSIZE=1000
if [ "$HISTCONTROL" = "ignorespace" ] ; then
    export HISTCONTROL=ignoreboth
else
    export HISTCONTROL=ignoredups
fi


JAVA_HOME=/usr/java/jdk1.7.0_72
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar:$CLASSPATH
PATH=$JAVA_HOME/bin:$PATH

然后执行

source /etc/profile

问题二：警告提示

[2016-11-06T16:27:21,712][WARN ][o.e.b.JNANatives ] unable to install syscall filter: 
java.lang.UnsupportedOperationException: seccomp unavailable: requires kernel 3.5+ with CONFIG_SECCOMP and CONFIG_SECCOMP_FILTER compiled in
at org.elasticsearch.bootstrap.Seccomp.linuxImpl(Seccomp.java:349) ~[elasticsearch-5.0.0.jar:5.0.0]
at org.elasticsearch.bootstrap.Seccomp.init(Seccomp.java:630) ~[elasticsearch-5.0.0.jar:5.0.0]

报了一大串错误，其实只是一个警告。

解决：使用心得Linux版本，就不会出现此类问题了。

问题三：ERROR: bootstrap checks failed

max file descriptors [4096] for elasticsearch process likely too low, increase to at least [65536]
max number of threads [1024] for user [lishang] likely too low, increase to at least [2048]

解决：切换到root用户，编辑limits.conf 添加类似如下内容

vi /etc/security/limits.conf

添加如下内容:

* soft nofile 65536

* hard nofile 131072

* soft nproc 2048

* hard nproc 4096

问题四：max number of threads [1024] for user [lish] likely too low, increase to at least [2048]

解决：切换到root用户，进入limits.d目录下修改配置文件。

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

修改如下内容：

* soft nproc 1024

修改为

* soft nproc 2048

问题五：max virtual memory areas vm.max_map_count [65530] likely too low, increase to at least [262144]

解决：切换到root用户修改配置sysctl.conf

vi /etc/sysctl.conf 

添加下面配置：

vm.max_map_count=655360

并执行命令：

sysctl -p

然后，重新启动elasticsearch，即可启动成功。