can not run elasticsearch as root
[o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root
解決方案：
因為安全問題 elasticsearch 不讓用 root 用戶直接運行，建議創(chuàng)建一個單獨的用戶用來運行
elasticsearch。我們可以創(chuàng)建 elsearch 用戶組及 elsearch 用戶，然后用這個用戶來啟動 elasticsearch。
groupadd elsearch
useradd elsearch -g elsearch -p elasticsearch
access denied
main ERROR Could not register mbeans java.security.AccessControlException: access denied ("javax.management.MBeanTrustPermission" "register")
解決方案：
root 用戶下，改變 elasticsearch-5.1.1 文件夾所有者給 elasticsearch 啟動用戶：
sudo chown -R elsearch:elsearch elasticsearch-5.1.1
There is insufficient memory for the Java Runtime Environment to continue
Cannot allocate memory
Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x0000000085330000, 2060255232, 0) failed; error='Cannot allocate memory' (errno=12)
There is insufficient memory for the Java Runtime Environment to continue.
解決方案：
修改 config/jvm.options，2g改成1g，也可以更小
-Xmx2g => -Xmx1g
unable to install syscall filter
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]
報了一大串錯誤，其實只是一個警告。
解決方案：
使用最新 Linux 版本，就不會出現(xiàn)此類問題了，可用忽略。
max number of threads [1024] for user [lish] likely too low, increase to at least [2048]
解決方案：
root 用戶下，進(jìn)入 limits.d 目錄下修改配置文件：
vim /etc/security/limits.d/90-nproc.conf
修改 soft nproc：
soft nproc 2048
max file descriptors for elasticsearch process likely too low
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]
解決方案：
root 用戶下，編輯 limits.conf：
vim /etc/security/limits.conf
添加如下內(nèi)容:
* soft nofile 65536
* hard nofile 65536
* soft nproc 2048
* hard nproc 4096
system call filters failed to install
ERROR: bootstrap checks failed
system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
解決方案：
修改 elasticsearch 配置文件：
vim config/elasticsearch.yml
增加配置：
bootstrap.system_call_filter: false
max virtual memory areas vm.max_map_count [65530] likely too low, increase to at least [262144]
解決方案：
root 用戶下，修改配置 sysctl.conf
vim /etc/sysctl.conf
添加下面配置：
vm.max_map_count=655360
執(zhí)行命令：
sysctl -p
重新啟動 elasticsearch
