Install latest Redis cache

Redis is an open source advanced key-value cache. It is high performance and often compared to memcached.

This post we look into how to install latest Redis cache onto (say) Fedora 21. It is quite simple, and lets start:

Goto http://redis.io/download, and download latest version using wget.

wget http://download.redis.io/releases/redis-2.8.19.tar.gz

untar/unzip the package

tar -xzvf redis-2.8.19.tar.gz

compile the bundle

cd redis-2.8.19
make

It is good to do a "make test" to test the functionality on your system. For this test you need tcl.

If you don't have tcl, install it by:

yum install tcl

Run make test:

make test

If functionality test passed it will show:

\o/ All tests passed without errors!

Lets install the excutables into /usr/local/bin/.

make install

For Fedora systemctl system, lets create a redis service script.

vi /usr/lib/systemd/system/redis.service

[Unit]
Description=Redis persistent key-value database
After=network.target

[Service]
ExecStart=/usr/local/bin/redis-server /etc/redis.conf --daemonize no
ExecStop=/usr/local/bin/redis-shutdown
User=redis
Group=redis

[Install]
WantedBy=multi-user.target

Move sample redis.conf to /etc.

cp /root/download/redis-2.8.19/redis.conf /etc/redis.conf

Create redis-shutdown script.

vi /usr/local/bin/redis-shutdown

#!/bin/bash
#
# Wrapper to close properly redis and sentinel
test x"$REDIS_DEBUG" != x && set -x

REDIS_CLI=/usr/local/bin/redis-cli

# Retrieve service name
SERVICE_NAME="$1"
if [ -z "$SERVICE_NAME" ]; then
   SERVICE_NAME=redis
fi

# Get the proper config file based on service name
CONFIG_FILE="/etc/$SERVICE_NAME.conf"

# Use awk to retrieve port from config file
PORT=`awk '/^[[:blank:]]*port/ { print $2 }' $CONFIG_FILE`

# Just in case, use default port
if [ "$SERVICE_NAME" = redis ]; then
    PORT=${PORT:-6379}
else
    PORT=${PORT:-26739}
fi

# shutdown the service properly
$REDIS_CLI -p $PORT SHUTDOWN NOSAVE

Enable and start redis service.

systemctl enable redis.service
systemctl start redis.service

Lets try the redis-cli. Set a key and get a key:

[root@fc21 temp]# redis-cli
127.0.0.1:6379> get key1
(nil)
127.0.0.1:6379> set key1 value1
OK
127.0.0.1:6379> get key1
"value1"

Install Nginx (and PHP) server on Fedora

Nginx [engine x] is a free high-perfomance HTTP and reverse proxy server, as well as a mail proxy server, written by Igor Sysoev.

Lets start the installation process:
Stop and disable existing apache.

# systemctl stop httpd.service
# systemctl disable httpd.service 

Install php-fpm

# yum install php-fpm -y

Enable and start php-fpm service:

# systemctl enable php-fpm.service
# systemctl start php-fpm.service

To install Nginx

# yum install nginx -y

Enable and start Nginx service

# systemctl enable nginx.service
# systemctl start nginx.service

Test Nginx

Open up your web browser and navigate to http://localhost/ (example). You will see the default nginx welcome screen.

Configure Nginx

Open the file /etc/nginx/nginx.conf in vi

# vi /etc/nginx/nginx.conf

Set the worker_processes (No. Of CPU’s in your system you want to utilise). To see the no. Of CPU’s, you can use the command “lscpu”. For default you can set to 1.
worker_processes 1;

Example of working nginx.conf:

# For more information on configuration, see:
#   * Official English Documentation: http://nginx.org/en/docs/
#   * Official Russian Documentation: http://nginx.org/ru/docs/

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log;
#error_log  /var/log/nginx/error.log  notice;
#error_log  /var/log/nginx/error.log  info;

pid        /run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    index   index.html index.htm;

    # Load modular configuration files from the /etc/nginx/conf.d directory.
    # See http://nginx.org/en/docs/ngx_core_module.html#include
    # for more information.
    include /etc/nginx/conf.d/*.conf;

    #Change below value to suit your need:
    fastcgi_read_timeout 6000s;

    server {
        listen       80 default_server;
        server_name  localhost;
        root         /usr/share/nginx/html;

        #charset koi8-r;

        #access_log  /var/log/nginx/host.access.log  main;

        # Load configuration files for the default server block.
        include /etc/nginx/default.d/*.conf;

        location / {
        }

        # redirect server error pages to the static page /40x.html
        #
        error_page  404              /404.html;
        location = /40x.html {
        }

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
        }

        location ~ [^/]\.php(/|$) {
           fastcgi_split_path_info ^(.+?\.php)(/.*)$;
           if (!-f $document_root$fastcgi_script_name) {
              return 404;
           }

           fastcgi_pass 127.0.0.1:9000;
           fastcgi_index index.php;
           include fastcgi_params;           
        }
    }
}

Save and close the file. Restart Nginx service:

# systemctl restart nginx.service

Test PHP

Create a sample “phpinfo.php” file in the nginx document root folder:

# vi /usr/share/nginx/html/phpinfo.php

Append the lines as shown below:

Save and close the file. Restart Nginx service:

# systemctl restart nginx.service

Navigate to http://localhost/testphp.php (example). It will display all the details about PHP,build,setups.

Monitoring page faults (page out)

Page-outs can be a sign of trouble. When the kernel detects that memory is running low, it attempts to free up memory by paging out. Though this may happen briefly from time to time, if page-outs are plentiful and constant, the kernel can reach a point where it's actually spending more time managing paging activity than running the applications, and system performance suffers. To monitor page-outs in the system, we can use vmstat. Below script display the amount of free memory for page-out. Ideally it should be zero.

#!/bin/bash
/usr/bin/vmstat | head -3 | tail -n +3 | awk {'print $8'}

[root@fc21 ~]# pageout
0

Monitoring swap space

To monitor the swap space available in the system, we can use free command. Below script display the swap space available in the system.

[root@fc21 ~]# cat /usr/local/sbin/swap
#!/bin/bash
/usr/bin/free | head -3 | tail -n +3 | awk {'print $3'}

[root@fc21 ~]# swap
1648

Monitoring ram

To monitor the free ram available in the system, we can use free command. Below script display the available ram.

#!/bin/bash
/usr/bin/free | head -2 | tail -n +2 | awk {'print $4'}

[root@fc21 ~]# ram
135720

Monitoring active tcp connections

Active tcp connections number brings us light on whether the system can serve the request fast. A high number indicate queuing/processing of requests. This number can be retrieved from netstat.

#!/bin/bash
tcp=$(/bin/netstat -nt | tail -n +3 | grep ESTABLISHED | wc -l)
printf "%s \n" "$tcp"

[root@fc21 ~]# tcp
5

Monitoring diskspace

To monitor the amount of hdd space used in the system, we can use df. Below script display the percentage the disk is used.

[root@fc21 ~]# cat /usr/local/sbin/disk
#!/bin/bash
/bin/df -t ext4 -m | awk {'print $5'} | tail -1

[root@fc21 ~]# disk
10%