Category: Linux

Simplest guide to config tomcat to use https with lets encrypt’s free cert

Support you have generate a standalone cert using certbot command, and your cert is in /etc/letsencrypt/live/ . If not, follow this https://www.digitalocean.com/community/tutorials/how-to-use-certbot-standalone-mode-to-retrieve-let-s-encrypt-ssl-certificates-on-ubuntu-16-04 Execute openssl command and remember your password Edit tomcat’s conf/server.xml, you just need one connector to serve 8443, no need other conntector Restart your tomcat, it is done. Below is the virtualhost to…
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Godaddy cheap VPS之經驗

係Godaddy起左隻最Cheap VPS, $160蚊個月, 得一粒vcore同1GB Ram, 行ubuntu + mysql + apache + wordpress. 正常黎講要兩三個星期restart一次mysql因為out of memory. 行wordpres兩年之後response time趑黎越慢, 有成十秒先load到個page. 裝左W3 Total Cache之後快左好多, 一兩秒就load到, 建議大家一定要裝.

Linux view csv command

alias csv=’column -s, -t’ csv your_file

ubuntu 12.04 vnc startup script for fallback mode

Fixed ubuntu vnc keymap problem

ubuntu 12.04 vnc keymap has trouble, D become minimize all windows and S become start menu, run these to fix it.

tomcat auto startup script

just save this to /etc/init.d/tomcat and link to /etc/rc5.d/S99tomcat

disable gnome “unable to mount…” dialog

gsettings set org.gnome.desktop.media-handling automount false …and enable it again: gsettings set org.gnome.desktop.media-handling automount true

why i receive zero in my socket

I have two programs, one written in c++, the other is in java. C++ keep sending bytes to java, overtime write out 400KB. Java keep receiving the data using the readBytes function, this function returns an integer which is the number of byte it actually read for the function call. For every send (400kb) in…
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[solved] usb wireless mouse freeze periodically in ubuntu 12.04 lts

usb wireless mouse freeze periodically in ubuntu 12.04 lts, edit /boot/grub/grub.cfg, add a boot option irqpoll will fix it

Add tabIndex to all tag incrementally

in VI, there is a command to add tabIndex to all tag incrementally :let i=200 | g/

My new server

Just bought a 2nd hand HP server (8core + 16GB ram), cost me $2630 HKD. One 1TB 2.5″ hard disk cost me $450. Total $3080. It reboot only take 20 seconds, dell needs 5 mins (CRAZY!!!)  

solved : compile error in ffmpeg “error: invalid combination of opcode and operands”‏

I am using ubuntu 12.04 64 bits and trying compile ffmpeg and got this error: libavfilter/x86/vf_pullup.asm:59: error: invalid combination of opcode and operands libavfilter/x86/vf_pullup.asm:138: error: invalid combination of opcode and operands libavfilter/x86/vf_pullup.asm:175: error: invalid combination of opcode and operands To solve this, add “–disable-mmx” to your ./configure

filter port in httpd.conf

A very professional ppt that talk about system performance tuning

A very professional ppt that talk about system performance tuning download : scalelinuxperformance-130224171331-phpapp01

How to use QMP, send command remotely to qemu

To use qmp and send command to qemu from another process, start qemu by This will create a file /tmp/test.gmp for interchange the command. Then you can start another terminal and invoke command.txt: !!! remark, must invoke { “execute”: “qmp_capabilities” } before invoke any qmp command