1、服务器本地端口监控：
过滤端口然后转成行数。
netstat -lntup|grep nginx|wc -l(推荐)
ss -lntup|grep nginx|wc -l
lsof -i :80|wc -l
2、远端端口监控：
看返回的行数，为1正常，否则不正常。
nmap 127.0.0.1 -p 80|grep open|wc -l(推荐)
echo -e "\n"|telnet 127.0.0.1 80 2>/dev/null|grep Connected|wc -l
看返回值，为0正常。
[root@web01 ~]# nc -z 127.0.0.1 80
[root@web01 ~]# echo $?
0
nc的控制参数不少，常用的几个参数如下所列：
1) -l
用于指定nc将处于侦听模式。指定该参数，则意味着nc被当作server，侦听并接受连接，而非向其它地址发起连接。
2) -p <port>
暂未用到（老版本的nc可能需要在端口号前加-p参数，下面测试环境是centos6.6，nc版本是nc-1.84，未用到-p参数）
3) -s
指定发送数据的源IP地址，适用于多网卡机
4) -u
指定nc使用UDP协议，默认为TCP
5) -v
输出交互或出错信息，新手调试时尤为有用
6）-w
超时秒数，后面跟数字
7）-z
表示zero，表示扫描时不发送任何数据
3、客户端模拟监控：看返回值或者看返回字符串
wget -q 127.0.0.1 &>/dev/null (推荐)
echo $?
curl 127.0.0.1 &>/dev/null
echo $?
7
看返回字符串是否为www7
[root@web01 /etc/nginx/conf.d]# curl -s 127.0.0.1 2>/dev/null(推荐)
www7
环境准备：
[root@oldboy ~]# touch /etc/rsyncd.conf
[root@oldboy ~]#
[root@oldboy ~]# rsync --daemon
[root@oldboy ~]# lsof -i :873
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
rsync 1690 root 4u IPv4 14658 0t0 TCP *:rsync (LISTEN)
rsync 1690 root 5u IPv6 14659 0t0 TCP *:rsync (LISTEN)
[root@oldboy ~]# pkill rsync
[root@oldboy ~]# lsof -i :873
启动脚本：
3、写一个rsync/sersync/nginx的启动脚本。
/etc/init.d/rsync {start|stop|restart}
C6:用chkconfig实现开机自启动管理。
C7:用systemctl实现开机自启动管理。
1）启动：rsync --daemon
2）停止：pkill rsync
kill `cat /var/run/rsyncd.pid`
3）监控手段：netstat -lntup|grep rsync|wc -l
/etc/init.d/rsyncd {start|stop|restart}
[root@oldboy init.d]# cat rsyncd
#!/bin/bash
if [ "$1" = "start" ]
then
if [ -f /var/run/rsyncd.pid -a -s /var/run/rsyncd.pid ]
then
:
else
rsync --daemon
fi
elif [ "$1" = "stop" ]
then
if [ -f /var/run/rsyncd.pid -a -s /var/run/rsyncd.pid ]
then
kill `cat /var/run/rsyncd.pid`
else
echo "Failed to stop rsync Unit rsync not loaded."
exit 1
fi
elif [ "$1" = "restart" ]
then
if [ -f /var/run/rsyncd.pid -a -s /var/run/rsyncd.pid ]
then
kill `cat /var/run/rsyncd.pid`
fi
sleep 2
if [ -f /var/run/rsyncd.pid -a -s /var/run/rsyncd.pid ]
then
:
else
rsync --daemon
fi
else
echo "Usage；$0 {start|stop|restart}"
fi
C7:systemctl
c6:管理开机自启动服务，用的chkconfig
[root@oldboy init.d]# cat /etc/redhat-release
CentOS release 6.9 (Final)
[root@oldboy init.d]#
[root@oldboy init.d]#
[root@oldboy init.d]#
[root@oldboy init.d]# chkconfig --list
abrt-ccpp 0:off 1:off 2:off 3:on 4:off 5:on 6:off
abrtd 0:off 1:off 2:off 3:on 4:off 5:on 6:off
acpid 0:off 1:off 2:on 3:on 4:on 5:on 6:off
atd 0:off 1:off 2:off 3:on 4:on 5:on 6:off
auditd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
blk-availability 0:off 1:on 2:on 3:on 4:on 5:on 6:off
cpuspeed 0:off 1:on 2:on 3:on 4:on 5:on 6:off
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
haldaemon 0:off 1:off 2:off 3:on 4:on 5:on 6:off
htcacheclean 0:off 1:off 2:off 3:off 4:off 5:off 6:off
httpd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
ip6tables 0:off 1:off 2:on 3:on 4:on 5:on 6:off
iptables 0:off 1:off 2:on 3:on 4:on 5:on 6:off
irqbalance 0:off 1:off 2:off 3:on 4:on 5:on 6:off
kdump 0:off 1:off 2:off 3:on 4:on 5:on 6:off
lvm2-monitor 0:off 1:on 2:on 3:on 4:on 5:on 6:off
mdmonitor 0:off 1:off 2:on 3:on 4:on 5:on 6:off
messagebus 0:off 1:off 2:on 3:on 4:on 5:on 6:off
netconsole 0:off 1:off 2:off 3:off 4:off 5:off 6:off
netfs 0:off 1:off 2:off 3:on 4:on 5:on 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off
nfs-rdma 0:off 1:off 2:off 3:off 4:off 5:off 6:off
ntpd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
ntpdate 0:off 1:off 2:off 3:off 4:off 5:off 6:off
postfix 0:off 1:off 2:on 3:on 4:on 5:on 6:off
psacct 0:off 1:off 2:off 3:off 4:off 5:off 6:off
quota_nld 0:off 1:off 2:off 3:off 4:off 5:off 6:off
rdisc 0:off 1:off 2:off 3:off 4:off 5:off 6:off
rdma 0:off 1:on 2:on 3:on 4:on 5:on 6:off
restorecond 0:off 1:off 2:off 3:off 4:off 5:off 6:off
rngd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
rsyslog 0:off 1:off 2:on 3:on 4:on 5:on 6:off
saslauthd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
smartd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
svnserve 0:off 1:off 2:off 3:off 4:off 5:off 6:off
sysstat 0:off 1:on 2:on 3:on 4:on 5:on 6:off
udev-post 0:off 1:on 2:on 3:on 4:on 5:on 6:off
[root@oldboy init.d]# chkconfig crond status
chkconfig version 1.3.49.5 - Copyright (C) 1997-2000 Red Hat, Inc.
This may be freely redistributed under the terms of the GNU Public License.
usage: chkconfig [--list] [--type <type>] [name]
chkconfig --add <name>
chkconfig --del <name>
chkconfig --override <name>
chkconfig [--level <levels>] [--type <type>] <name> <on|off|reset|resetpriorities>
[root@oldboy init.d]# chkconfig --list crond
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@oldboy init.d]# chkconfig crond off
[root@oldboy init.d]# chkconfig --list crond
crond 0:off 1:off 2:off 3:off 4:off 5:off 6:off
[root@oldboy init.d]# chkconfig crond on
[root@oldboy init.d]# chkconfig --list crond
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@oldboy init.d]# chkconfig --level 3 crond off
[root@oldboy init.d]# chkconfig --list crond
crond 0:off 1:off 2:on 3:off 4:on 5:on 6:off
[root@oldboy init.d]# chkconfig --level 45 crond off
[root@oldboy init.d]# chkconfig --list crond
crond 0:off 1:off 2:on 3:off 4:off 5:off 6:off
[root@oldboy init.d]# chkconfig --list rsyncd
service rsyncd does not support chkconfig
For example, random.init has these three lines:
# chkconfig: 2345 20 80
# description: Saves and restores system entropy pool for \
# higher quality random number generation.
This says that the random script should be started in levels 2, 3, 4, and 5, that its start priority
should be 20, and that its stop priority should be 80. You should be able to figure out what the
description says; the \ causes the line to be continued. The extra space in front of the line is
ignored.
[root@oldboy init.d]# ll /etc/init.d/rsyncd
-rwxr-xr-x. 1 root root 763 May 30 09:55 /etc/init.d/rsyncd
[root@oldboy init.d]# chmod +x /etc/init.d/rsyncd
[root@oldboy init.d]# chkconfig --add rsyncd
[root@oldboy init.d]# chkconfig --list rsyncd
rsyncd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@oldboy init.d]# head -3 rsyncd
#!/bin/bash
# chkconfig: 2345 21 81
# description: startup rsync scripts
[root@oldboy init.d]# chkconfig rsyncd off
[root@oldboy init.d]# chkconfig --list rsyncd
rsyncd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
[root@oldboy init.d]# chkconfig rsyncd on
[root@oldboy init.d]# chkconfig --list rsyncd
rsyncd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@oldboy init.d]# ls /etc/rc.d/rc3.d/|grep rsync
S21rsyncd
[root@oldboy init.d]# ls /etc/rc.d/rc3.d/-l|grep rsync
ls: cannot access /etc/rc.d/rc3.d/-l: No such file or directory
[root@oldboy init.d]# ls /etc/rc.d/rc3.d/ -l|grep rsync
lrwxrwxrwx. 1 root root 16 May 30 09:58 S21rsyncd -> ../init.d/rsyncd
[root@oldboy init.d]# chkconfig rsyncd off
[root@oldboy init.d]# ls /etc/rc.d/rc3.d/ -l|grep rsync
lrwxrwxrwx. 1 root root 16 May 30 09:59 K81rsyncd -> ../init.d/rsyncd
cat >/etc/systemd/system/oldboy_rsync.service<<EOF
[Unit]
Description=MySQL Server by oldboy
Documentation=man:mysqld(8)
Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html
After=network.target
After=syslog.target
[Install]
WantedBy=multi-user.target
[Service]
User=rsync
Group=rsync
ExecStart=/etc/init.d/rsyncd start
LimitNOFILE = 5000
EOF
systemctl start mysqld
systemctl enable mysqld
netstat -lntup|grep mysql
