Install Tinyproxy on Centos 7

Tinyproxy is a light-weight HTTP/HTTPS proxy daemon for POSIX operating systems.
Designed from the ground up to be fast and yet small, it is an ideal solution for use cases such as embedded deployments where a full featured HTTP proxy is required, but the system resources for a larger proxy are unavailable.

yum install -y epel-release
yum update -y
yum -y install tinyproxy
yum install vim -y

vim /etc/tinyproxy/tinyproxy.conf

Search for

Port 8888

Then
Search for:

Allow xxx.xxx.xxx.xxx

If you want to let it connect from anywhere then just comment it, but I’m not recommended, because it will allow other user connect in.

To test from the Allowed server to the TinyProxy Server

ssh [email protected] -L 1234:localhost:8888 -N

curl -I https://juzhax.com/ --proxy [email protected]:8888

How to clear nginx cache manually ?

Normally I like to do manually job.

assume that the default path of your nginx cache is /var/cache/nginx

find /var/cache/nginx -type f -delete

This will clear all your cache in one line.

Delete a single file from nginx cache

If you just want to delete a single file from nginx cache, you can try this.

grep -lr '//juzhax.com/wp-content/plugins/jetpack/modules/wpgroho.js' /var/cache/nginx*

Then it will show something like this
/var/cache/nginx/8/45/6025f6b505cd8cbc1172d4e541ac3458

You can safely remove by using rm

rm /var/cache/nginx/8/45/6025f6b505cd8cbc1172d4e541ac3458

WARNING: /sys/kernel/mm/transparent_hugepage/enabled is ‘always’.

After I install MongoDB 3.2.3 in Centos 7, I received this error when I start mongo in shell.

[[email protected] ~]# mongo
MongoDB shell version: 3.2.3
connecting to: test
Server has startup warnings:
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten]
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten]
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten]
2016-02-29T14:11:49.308-0500 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 4096 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.

Solution

Create the init.d script.
Create the following file at /etc/init.d/disable-transparent-hugepages:

#!/bin/sh
### BEGIN INIT INFO
# Provides:          disable-transparent-hugepages
# Required-Start:    $local_fs
# Required-Stop:
# X-Start-Before:    mongod mongodb-mms-automation-agent
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Disable Linux transparent huge pages
# Description:       Disable Linux transparent huge pages, to improve
#                    database performance.
### END INIT INFO

case $1 in
  start)
    if [ -d /sys/kernel/mm/transparent_hugepage ]; then
      thp_path=/sys/kernel/mm/transparent_hugepage
    elif [ -d /sys/kernel/mm/redhat_transparent_hugepage ]; then
      thp_path=/sys/kernel/mm/redhat_transparent_hugepage
    else
      return 0
    fi

    echo 'never' > ${thp_path}/enabled
    echo 'never' > ${thp_path}/defrag

    unset thp_path
    ;;
esac

Make it executable.
Run the following command to ensure that the init script can be used:

sudo chmod 755 /etc/init.d/disable-transparent-hugepages
sudo chkconfig --add disable-transparent-hugepages

WARNING: Cannot detect if NUMA interleaving is enabled. Failed to probe “/sys/devices/system/node/node1”: Permission denied

[[email protected] ~]# mongo
MongoDB shell version: 3.2.3
connecting to: test
Server has startup warnings:
2016-02-29T23:11:36.666+0700 I CONTROL  [initandlisten]
2016-02-29T23:11:36.667+0700 I CONTROL  [initandlisten] ** WARNING: Cannot detect if NUMA interleaving is enabled. Failed to probe "/sys/devices/system/node/node1": Permission denied
2016-02-29T23:11:36.667+0700 W CONTROL  [initandlisten]
2016-02-29T23:11:36.667+0700 W CONTROL  [initandlisten] Failed to probe "/sys/kernel/mm/transparent_hugepage": Permission denied
2016-02-29T23:11:36.667+0700 W CONTROL  [initandlisten]
2016-02-29T23:11:36.667+0700 W CONTROL  [initandlisten] Failed to probe "/sys/kernel/mm/transparent_hugepage": Permission denied
2016-02-29T23:11:36.667+0700 I CONTROL  [initandlisten]
2016-02-29T23:11:36.667+0700 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 4096 processes, 262144 files. Number of processes should be at least 131072 : 0.5 times number of files.

Solution

I’m using the OVH kernel, so it is impossible to use with MongoDB, to solve this issue I have to install back the original kernel of the linux, then this error will be gone.