運維工做中常常用到的一些知識總結（三）

接上篇：
http://www.javashuo.com/article/p-aenkdxzo-ks.html

4八、容器導出導入：

docker import 容器ID > xxx.tar
    cat xxx.tar | docker import - xxx:v1.0

鏡像導出導入：

docker save xxx:v1.0 > yyyy.tar.gz
    docker load < yyyy.tar.gz

4九、docker

卸載：

yum remove docker \
docker-common \
docker-selinux \
docker-engine

安裝依賴：

yum -y install yum-utils device-mapper-persistent-data lvm2

設置源：

yum-config-manager \
--add-repo \
https://mirrors.ustc.edu.cn/docker-ce/linux/centos/docker-ce.repo

安裝：

yum makecache fast
yum -y install docker-ce

docker-enter:

.bashrc_docker

#Some useful commands to use docker.
#Author: yeasy@github
#Created:2014-09-25

alias docker-pid="sudo docker inspect --format '{{.State.Pid}}'"
alias docker-ip="sudo docker inspect --format '{{ .NetworkSettings.IPAddress }}'"

#the implementation refs from https://github.com/jpetazzo/nsenter/blob/master/docker-enter
function docker-enter() {
    #if [ -e $(dirname "$0")/nsenter ]; then
    #Change for centos bash running
    if [ -e $(dirname '$0')/nsenter ]; then
        # with boot2docker, nsenter is not in the PATH but it is in the same folder
        NSENTER=$(dirname "$0")/nsenter
    else
        # if nsenter has already been installed with path notified, here will be clarified
        NSENTER=$(which nsenter)
        #NSENTER=nsenter
    fi
    [ -z "$NSENTER" ] && echo "WARN Cannot find nsenter" && return

    if [ -z "$1" ]; then
        echo "Usage: `basename "$0"` CONTAINER [COMMAND [ARG]...]"
        echo ""
        echo "Enters the Docker CONTAINER and executes the specified COMMAND."
        echo "If COMMAND is not specified, runs an interactive shell in CONTAINER."
    else
        PID=$(sudo docker inspect --format "{{.State.Pid}}" "$1")
        if [ -z "$PID" ]; then
            echo "WARN Cannot find the given container"
            return
        fi
        shift

        OPTS="--target $PID --mount --uts --ipc --net --pid"

        if [ -z "$1" ]; then
            # No command given.
            # Use su to clear all host environment variables except for TERM,
            # initialize the environment variables HOME, SHELL, USER, LOGNAME, PATH,
            # and start a login shell.
            #sudo $NSENTER "$OPTS" su - root
            sudo $NSENTER --target $PID --mount --uts --ipc --net --pid su - root
        else
            # Use env to clear all host environment variables.
            sudo $NSENTER --target $PID --mount --uts --ipc --net --pid env -i $@
        fi
    fi
}

echo "[ -f ~/.bashrc_docker ] && . ~/.bashrc_docker " >> ~/.bashrc; source ~/.bashrc

50、tomcat啓動很是慢，要花5~6分鐘

http://blog.csdn.net/sxhong/article/details/62889003
有兩種解決辦法：

1）在Tomcat環境中解決

能夠經過配置JRE使用非阻塞的Entropy Source。
在catalina.sh中加入這麼一行：-Djava.security.egd=file:/dev/./urandom 便可。
加入後再啓動Tomcat，整個啓動耗時降低到Server startup in 2912 ms。

2）在JVM環境中解決

打開$JAVA_PATH/jre/lib/security/java.security這個文件，找到下面的內容：
securerandom.source=file:/dev/urandom
替換成
securerandom.source=file:/dev/./urandom

5一、定時釋放mem腳本

[root@master script]# vim freemem.sh

#!/bin/bash

used=`free -m | awk 'NR==2' | awk '{print $3}'`
free=`free -m | awk 'NR==2' | awk '{print $4}'`

echo "===========================" >> /var/log/mem.log
date >> /var/log/mem.log
echo "Memory usage | [Use：${used}MB][Free：${free}MB]" >> /var/log/mem.log

if [ $free -le 6350 ] ; then
                sync && echo 1 > /proc/sys/vm/drop_caches
                sync && echo 2 > /proc/sys/vm/drop_caches
                sync && echo 3 > /proc/sys/vm/drop_caches
                echo "bobo365" >> /var/log/mem.log
else
                echo "Not required" >> /var/log/mem.log
fi

*/30 * * * * /bin/bash /home/script/freemem.sh &>/dev/null

5二、activemq

http://blog.csdn.net/xiaoxing598/article/details/51604999
http://activemq.apache.org/activemq-5153-release.html

tar xf xxx -C /usr/local
cd /usr/local/xxx/bin
./activemq start

vim conf/jetty-realm.properties
#將裏面的內容清空，從新添加一行
admin: Admin!123, admin

vim conf/jetty.xml
#修改第30行變成以下
<property name="roles" value="admin" />

vim conf/activemq.xml
保留openwire   stomp

5三、MFS

curl "http://ppa.moosefs.com/RPM-GPG-KEY-MooseFS" > /etc/pki/rpm-gpg/RPM-GPG-KEY-MooseFS
curl "http://ppa.moosefs.com/MooseFS-3-el7.repo" > /etc/yum.repos.d/MooseFS.repo
yum install moosefs-master moosefs-cgi moosefs-cgiserv moosefs-cli
yum install moosefs-chunkserver
yum install moosefs-metalogger
yum install moosefs-client

cd /etc/mfs/
[root@bobo365 mfs]# egrep -v "#|^$" mfsexports.cfg

10.150.27.0/24                  /       rw,alldirs,mapall=mfs:mfs,password=111111
*                       .       rw

[root@bobo365 mfs]# egrep -v "#|^$" mfshdd.cfg

/mfsdata

[root@bobo365 mfs]# egrep -v "#|^$" mfsmetalogger.cfg

ASTER_HOST = 10.150.27.113
MASTER_PORT = 9419

[root@bobo365 mfs]# egrep -v "#|^$" mfschunkserver.cfg

MASTER_HOST = mfsmaster
MASTER_PORT = 9420
AUTH_CODE = 111111

mkdir /mfsdata
chown -R mfs.mfs /mfsdata/

客戶端：

mkdir /mnt/mfs
chown -R mfs.mfs /mnt/mfs/

mfsmount /mnt/mfs -H 10.150.27.113 -o mfspassword=111111

[root@bobo365 mfs]# more /etc/hosts
10.150.27.113 bobo365 mfsmaster

http://10.150.27.113:9425

一、啓動master
二、啓動全部chunkserver
三、啓動metalogger
四、掛載客戶端
中止反序。

systemctl start moosefs-master.service
systemctl start moosefs-chunkserver.service
systemctl start moosefs-cgiserv.service
systemctl start moosefs-metalogger.service

systemctl status moosefs-master.service
systemctl status moosefs-chunkserver.service
systemctl status moosefs-cgiserv.service
systemctl status moosefs-metalogger.service

systemctl enable moosefs-master.service
systemctl enable moosefs-chunkserver.service
systemctl enable moosefs-cgiserv.service
systemctl enable moosefs-metalogger.service

more /etc/rc.local
mfsmount /mnt/mfs -H 10.150.27.113 -o mfspassword=111111