SoftElf.com

BTS V performance

2018-08-29T19:34:00.004-04:00

https://www.twiceweb.net/board/view/ent_bangtan/30

BTS V his home life with his family

2018-08-29T19:32:00.001-04:00

he looks so happy! 😊

https://www.twiceweb.net/board/view/ent_bangtan/22

How to set up MySQL max connections

2018-08-29T18:58:00.001-04:00

This shows current max connections for mysql.

mysql> show variables like 'max_connections';

This shows current used connections for now.

mysql> show status like 'Max_used_connections';

To check how many connections were aborted. If you see aborted connection, you might need to increase max connection settings.

mysql> show status like 'Aborted%';

To change max connections:

mysql> set global max_connections=300;

If you want permanent settings:

# vi /etc/my.cnf

[mysqld]

max_connections = 300

You need to restart to make the change of /etc/my.cnf to be effective.

service mysqld restart

and check it again:

mysql> show variables like 'max_connections';

https://www.twiceweb.net/board/view/software/12

How to check HTTPS active connections on linux

2018-08-29T18:57:00.005-04:00

netstat -an | grep :443 | grep ESTABLISHED | wc -l

https://www.twiceweb.net/board/view/software/11

[MySQL] reducing memory usage on cloud server

2018-08-29T18:57:00.003-04:00

in /etc/mysql/my.cnf

[mysqld]

performance_schema=OFF

https://www.twiceweb.net/board/view/software/9

how to use crontab [linux]

2018-08-29T18:57:00.001-04:00

* listing current crontab:

crontab -l

* editing crontab:

crontab -e

* example (once every 1st day of month):

0 0 1 * * shell_command_here

* special strings:

string         meaning
------         -------
@reboot        Run once, at startup.
@yearly        Run once a year, "0 0 1 1 *".
@annually      (same as @yearly)
@monthly       Run once a month, "0 0 1 * *".
@weekly        Run once a week, "0 0 * * 0".
@daily         Run once a day, "0 0 * * *".
@midnight      (same as @daily)
@hourly        Run once an hour, "0 * * * *".

https://www.twiceweb.net/board/view/software/8

Vultr Tokyo sysbench performance benchmark result

2018-08-29T18:56:00.001-04:00

vultr performance test result (Tokyo region)

1 vCPU@2.4GHz

1GB RAM

25GB SSD

1TB traffic

$5/month

sysbench CPU test : 298 events/s

sysbench memory : 2850MB/s

sysbench file I/O :

read: 21.77MB/s

write: 14.51MB/s

sysbench mysql

read-only : 455 transactions/s, 7289 queries/s

read-write : 149 transactions/s, 2988 queries/s

write-only : 280.89 transactions/s, 1685 queries/s

https://www.twiceweb.net/board/view/computer/28

how to redirect HTTP to HTTPS on nginx

2018-08-29T18:55:00.005-04:00

sudo vi /etc/nginx/sites-available/SITEDOMAIN

server {

listen 80 default_server;

listen [::]:80 default_server;

server_name _;

return 301 https://$host$request_uri;

}

The first listen statement is for HTTP port of IPv4.

The second listen statement if for HTTP port of IPv6.

You can redirect from specific domain name as following:

server_name example.com www.example.com

https://www.twiceweb.net/board/view/computer/22

how to check the file count in a folder (Ubuntu,CentOS,Linux)

2018-08-29T18:55:00.003-04:00

find . -type f | wc -l

https://www.twiceweb.net/board/view/computer/21

how to check disk space usage or free disk space on Ubuntu

2018-08-29T18:55:00.001-04:00

$ df -h

the result:

Filesystem Size Used Avail Use% Mounted on
udev 464M 0 464M 0% /dev
tmpfs 99M 664K 98M 1% /run
/dev/vda1 25G 4.9G 19G 21% /

https://www.twiceweb.net/board/view/computer/20

how to check ubuntu free memory

2018-08-29T18:54:00.005-04:00

$ free -m

you see like the following:

total used free shared buff/cache available
Mem: 985 661 191 1 132 185
Swap: 0 0 0

If you want memory usage and CPU consumption of each process:

$ top

$ htop

htop highlights information with color texts.

https://www.twiceweb.net/board/view/computer/19

How to change timezone on Ubuntu 18.x

2018-08-29T18:54:00.003-04:00

Check current timezone

$ timedatectl

Show available timezones

$ timedatectl list-timezone

Change timezone

$ sudo timedatectl set-timezone Asia/Seoul

https://www.twiceweb.net/board/view/computer/18

how to use ubuntu firewall (ufw) 우분투 방화벽 ufw사용하는 법

2018-08-29T18:54:00.001-04:00

Warning: If you enable ufw, then the default rule might block everything including your remote terminal connection.

기본 규칙 확인하기

check the default rule

$ cat /etc/default/ufw

ufw상태확인

check ufw status :

$ sudo ufw status verbose

기본정책 설정하기 : 기본적으로 들어오는 패킷은 모두 막고, 서버에서 나가는 패킷은 모두 허용합니다.

set up default policies

$ sudo ufw default deny incoming

$ sudo ufw default allow outgoing

SSH연결 허용하기 (필수. 이 규칙이 없으면 원격터미널연결이 불가능해집니다.)

allow SSH connections (you need this rule to connect to your server via remote terminal program)

$ sudo ufw allow ssh

or allow port 22 (default ssh port = 22)

$ sudo ufw allow 22

UFW켜기

enable UFW

$ sudo ufw enable

UFW상태 확인

check ufw status

$ sudo ufw status verbose

HTTP허용하기

allow HTTP (if you need)

$ sudo ufw allow http

$ sudo ufw allow 80

HTTPS허용하기

allow HTTPS (if you need)

$ sudo ufw allow https

$ sudo ufw allow 443

포트범위 허용하기

allow specific port ranges (ex. 3000~3003 TCP port)

$ sudo ufw allow 3000:3003/tcp

IP주소 허용하기

allow specific IP address

$ sudo ufw allow from 11.12.13.14

IP & port allow rule:

$ sudo ufw allow from 11.12.13.14 to any port 22

서브넷 허용하기

allow subnets (ex. 11.12.13.1 ~ 11.12.13.254)

$ sudo ufw allow from 11.12.13.0/24

연결 막기

deny connections

$ sudo ufw deny ftp

or deny port 21

$ sudo ufw deny 21

or deny ip address

$ sudo ufw deny from 11.12.13.14

방화벽규칙번호 확인

list firewall rule number

$ sudo ufw status numbered

번호로 방화벽규칙 삭제

delete ufw rule by rule number (ex. delete ufw rule number 2)

$ sudo ufw delete 2

내용으로 방화벽규칙 삭제

delete ufw rule by actual rule

$ sudo ufw delete allow http

UFW방화벽 끄기

disable UFW firewall

$ sudo ufw disable

https://www.twiceweb.net/board/view/computer/17

Vultr Tokyo sysbench performance benchmark result

2018-08-29T18:14:00.003-04:00

vultr performance test result (Tokyo region)

1 vCPU@2.4GHz

1GB RAM

25GB SSD

1TB traffic

$5/month

sysbench CPU test : 298 events/s

sysbench memory : 2850MB/s

sysbench file I/O :

read: 21.77MB/s

write: 14.51MB/s

sysbench mysql

read-only : 455 transactions/s, 7289 queries/s

read-write : 149 transactions/s, 2988 queries/s

write-only : 280.89 transactions/s, 1685 queries/s

https://www.twiceweb.net/board/view/computer/28

twiceweb.net : fun site

2017-10-08T22:42:00.003-04:00

https://www.twiceweb.net

Talkboard android app

2017-09-23T22:24:00.001-04:00

https://play.google.com/store/apps/details?id=kr.twiceweb.talkboard

anonymous talk app

BetaRunner 1.13 for iOS, Android has been released.

2015-12-10T08:55:00.003-05:00

added a new map, "Kyoto".

BlankPage app for iOS and Android provides Pencil Drawing Filter.

2015-07-30T23:24:00.002-04:00

BetaRunner has been released in Android Playstore.

2015-07-14T10:23:00.001-04:00

https://play.google.com/store/apps/details?id=com.softelf.alpharun

DCMetroGo new version app is going to be released.

2015-07-02T10:03:00.002-04:00

* silver line has been updated.

* hardware acceleration is used for drawing.

https://play.google.com/store/apps/details?id=com.softelf.dcmetrogo2

CubPic has been released for Android

2014-05-08T11:22:00.002-04:00

Use CubPic to draw pictures with 3D cubes.

It supports 64 colors and an eraser.

Enjoy this toy.

BlankPage - Pixels for iPad & iPhone has been released.

2012-05-04T19:35:00.003-04:00

create your own pixel art!

BlankPage for Android 1.5 has been released.

2012-04-29T11:26:00.001-04:00

line drawing performance optimization.

FreeShotHD 2.0 has been released

2012-01-21T09:18:00.002-05:00

new backgrounds

BlankPage 1.5

2011-11-24T08:43:00.001-05:00