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Safest way to clean up boot partition - Ubuntu 14.04LTS-x64

Reference

Case I: if /boot is not 100% full and apt is working

1. Check the current kernel version

$ uname -r 

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Sample config for 2 million web socket connection

    sysctl -w fs.file-max=12000500
    sysctl -w fs.nr_open=20000500
    # Set the maximum number of open file descriptors
    ulimit -n 20000000

    # Set the memory size for TCP with minimum, default and maximum thresholds 
 sysctl -w net.ipv4.tcp_mem='10000000 10000000 10000000'

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apt-get update && apt-get install -y apt-transport-https

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add

vim /etc/apt/sources.list.d/kubernetes.list

deb http://apt.kubernetes.io/ kubernetes-xenial main

apt-get update

apt-get install -y kubelet kubeadm kubectl kubernetes-cni

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#!/bin/bash

docker run --name CasDC1SeedOne \
 -e WEAVE_CIDR=10.10.10.5/16   \
 -e CASSANDRA_CLUSTER_NAME=CPUT \
 -e CASSANDRA_DC=DC1 \
 -e CASSANDRA_RACK=RC1 \
 -e CASSANDRA_ENDPOINT_SNITCH=GossipingPropertyFileSnitch \
 -v /data/cassandra/node1:/var/lib/cassandra \
 -e CASSANDRA_SEEDS=10.10.10.5,10.10.10.15 \

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Latency Comparison Numbers
--------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

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Advanced Functional Programming with Scala - Notes

Copyright © 2017 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

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-XX:MaxPermSize=384M
-Dhttps.proxyHost=10.18.8.9
-Dhttps.proxyPort=3128
-Dhttps.proxyUser=user
-Dhttps.proxyPassword=pass
-Dhttp.proxyHost=10.18.8.9
-Dhttp.proxyPort=3128
-Dhttp.proxyUser=user
-Dhttp.proxyPassword=passwd

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docker build -t bonifacekabaso/cassandrad:2.2.6 \
            --build-arg http_proxy="http://[USER]:[PASSWD]@[IP]:[PORT]" \
            --build-arg https_proxy="http://[USER]:[PASSWD]@[IP]:[PORT]" \
            .

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UPDATE wp_options SET option_value = replace(option_value, 'http://www.oldsite.com', 'http://www.newsite.com') WHERE option_name = 'home' OR option_name = 'siteurl';
UPDATE wp_posts SET guid = replace(guid, 'http://www.oldsite.com','http://www.newsite.com');
UPDATE wp_posts SET post_content = replace(post_content, 'http://www.oldsite.com', 'http://www.newsite.com');
UPDATE wp_postmeta SET meta_value = replace(meta_value, 'http://www.oldsite.com', 'http://www.newsite.com');

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# Tweaked from http://tomislavsantek.iz.hr/2011/03/moving-mysql-databases-to-ramdisk-in-ubuntu-linux

# Log in as root
# Mount ramdisk folder in RAM
mkdir /tmp/ramdisk
mount -t tmpfs -o size=128M tmpfs /tmp/ramdisk/

# Move MySQL data
mv /var/lib/mysql /tmp/ramdisk/mysql
ln -s /tmp/ramdisk/mysql/ /var/lib/mysql