Boniface Kabaso boniface

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

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

1. Check the current kernel version

$ uname -r

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'

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

Advanced Functional Programming with Scala - Notes

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

	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

	dockerCommands := Seq(
	Cmd("FROM", "anapsix/alpine-java:jdk8"),
	Cmd("MAINTAINER", maintainer.value),
	Cmd("WORKDIR", "/opt/docker"),
	Cmd("ADD", "/opt /opt"),
	ExecCmd("RUN", "chown", "-R", "daemon:daemon", "."),
	Cmd("USER", "daemon"),
	ExecCmd("ENTRYPOINT", "bin/hashbot"),
	ExecCmd("CMD", "")
	)

	#!/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 \

	-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

	#Create Group

	# groupadd tomcat
	# useradd -g tomcat -d /usrlocal/tomcat8 tomcat
	# usermod -G www-data tomcat
	# chown tomcat:tomcat /usrlocal/tomcat8 -R
	# vim /etc/init.d/tomcat


	#!/bin/sh

	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]" \
	.