无法在 Centos 7 上启动 redis 服务器答案

【问题标题】：Can't start redis server on Centos 7无法在 Centos 7 上启动 redis 服务器
【发布时间】：2017-03-19 19:48:14
【问题描述】：

我正在尝试安装 OpenVas，但在 CentOS 上启动 Redis 服务器时遇到问题。我应该怎么做才能解决问题？

我通过运行安装openvas（这会安装redis和所有其他依赖项）：

# yum install openvas

我尝试通过运行来启动它：

# systemctl enable redis && systemctl restart redis

我通过运行检查 systemctl 状态日志中的 redis：

# systemctl status redis -l

显示连接被拒绝，无法启动：

Mar 19 12:37:13 hostname.local systemd[1]: Started Redis persistent key-value database.
Mar 19 12:37:13 hostname.local systemd[1]: Starting Redis persistent key-value database...
Mar 19 12:37:14 hostname.local systemd[1]: redis.service: main process exited, code=exited, status=1/FAILURE
Mar 19 12:37:14 hostname.local redis-shutdown[19127]: Could not connect to Redis at 127.0.0.1:6379: Connection refused
Mar 19 12:37:14 hostname.local systemd[1]: redis.service: control process exited, code=exited status=1
Mar 19 12:37:14 hostname.local systemd[1]: Unit redis.service entered failed state.
Mar 19 12:37:14 hostname.local systemd[1]: redis.service failed.

【问题讨论】：

标签： redis centos centos7

【解决方案1】：

首先，查看 /var/log/redis/redis.log

我尝试使用这篇文章进行设置 https://forums.atomicorp.com/viewtopic.php?f=31&t=8047

1) Disable SELINUX.
Edit /etc/selinux/config, save and reboot
2) Add required packages
yum install wget bzip2 texlive net-tools alien
3) Add Atomicorp repo
wget -q -O - http://www.atomicorp.com/installers/atomic | sh
4) Install OpenVAS 
yum install openvas
5) edit /etc/redis.conf. Add/uncomment the following
unixsocket /tmp/redis.sock
unixsocketperm 700
6) Restart Redis
systemctl enable redis && systemctl restart redis

redis ip 启动并运行

[root@localhost ~]# cat /var/log/redis/redis.log
                _._
           _.-``__ ''-._
      _.-``    `.  `_.  ''-._           Redis 3.2.3 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 29645
  `-._    `-._  `-./  _.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |           http://redis.io
  `-._    `-._`-.__.-'_.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |
  `-._    `-._`-.__.-'_.-'    _.-'
      `-._    `-.__.-'    _.-'
          `-._        _.-'
              `-.__.-'

29645:M 21 Mar 14:55:00.551 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
29645:M 21 Mar 14:55:00.551 # Server started, Redis version 3.2.3
29645:M 21 Mar 14:55:00.551 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
29645:M 21 Mar 14:55:00.551 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
29645:M 21 Mar 14:55:00.551 * The server is now ready to accept connections on port 6379

【讨论】：

【解决方案2】：

是否启用了 SELinux？您可以使用以下命令进行检查：

$ getenforce

如果是'Enforcing'，可能redis被SELinux策略阻止了，你能不能也检查一下/etc/redis.conf？找到以'unixsocket'开头的行，如果是/tmp/redis.sock，尝试将其更改为'/var/run/redis/redis.sock'：

unixsocket /var/run/redis/redis.sock

然后重启redis服务器，检查服务器状态，OpenVAS设置需要redis在unix socket上监听。

【讨论】：

【解决方案3】：

CentOs8 配置私网

更新防火墙服务以允许来自专用网络的传入连接：

sudo firewall-cmd --permanent --zone=trusted --change-interface=ens7

是平均接口网络名称 2.创建一个systemd服务来延迟Redis启动，直到私有接口启动并分配IP地址

sudo nano /etc/systemd/system/redis.service.d/wait-for-ips.conf

将以下文本粘贴到文件中，然后保存并关闭它：

[单位] After=network-online.target Wants=network-online.target
重新加载服务

sudo systemctl daemon-reload
重启服务

sudo systemctl restart redis.service

谢谢信用 https://www.vultr.com/docs/install-and-configure-redis-on-centos-8

【讨论】：