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@kapkaev
kapkaev / gist:4619127
Created January 24, 2013 09:30
MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Commands that may modify the data set are disabled. Please check Redis logs for details about the error. Resque
$ redis-cli
> config set stop-writes-on-bgsave-error no
@kapkaev
kapkaev / 0: jvm-options-java8.conf
Created June 16, 2016 23:00 — forked from elifarley/0: jvm-options-java8.conf
JVM options to maximize performance
# See https://docs.oracle.com/javase/8/docs/technotes/tools/windows/java.html
# See https://docs.oracle.com/javase/8/docs/technotes/guides/vm/performance-enhancements-7.html
# See https://docs.oracle.com/javase/8/embedded/develop-apps-platforms/codecache.htm
# See http://normanmaurer.me/blog_in_progress/2013/11/07/Inline-all-the-Things/
# See http://stas-blogspot.blogspot.com.br/2011/07/most-complete-list-of-xx-options-for.html
# -XX:+LogCompilation
# -XX:+PrintInlining
-Dfile.encoding=UTF-8
@kapkaev
kapkaev / Slug.scala
Created August 4, 2017 17:17 — forked from sam/Slug.scala
package util
object Slug {
def apply(input:String) = slugify(input)
def slugify(input: String): String = {
import java.text.Normalizer
Normalizer.normalize(input, Normalizer.Form.NFD)
.replaceAll("[^\\w\\s-]", "") // Remove all non-word, non-space or non-dash characters
.replace('-', ' ') // Replace dashes with spaces
def findAvailablePort(): Int = {
val socket = new ServerSocket(0)
socket.setReuseAddress(true)
val port = socket.getLocalPort
socket.close()
port
}
@kapkaev
kapkaev / System Design.md
Created April 18, 2016 06:12 — forked from vasanthk/System Design.md
System Design Cheatsheet

#System Design Interview Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

##Basic Steps

  1. Clarify and agree on the scope of the system
  • User cases (description of sequences of events that, taken together, lead to a system doing something useful)
    • Who is going to use it?
    • How are they going to use it?
@kapkaev
kapkaev / kafka_topics.sh
Last active October 1, 2018 20:08
Calculate kafka topics sizes
#!/usr/bin/ruby
require 'net/ssh'
require 'pp'
def fetch(host)
data = []
Net::SSH.start(host, 'virool') do |ssh|
index_folders = ssh.exec!("ls -d /var/lib/kafka/*").split("\n")
data = index_folders.flat_map do |ifolder|
@kapkaev
kapkaev / gzip.rb
Last active September 13, 2018 17:10
Faraday::Response::Gzip middleware
require 'faraday'
require 'zlib'
module Faraday
class Response::Gzip < Response::Middleware
def on_complete(env)
encoding = env[:response_headers]['content-encoding'].to_s.downcase
case encoding
when 'gzip'
env[:body] = Zlib::GzipReader.new(StringIO.new(env[:body]), encoding: 'ASCII-8BIT').read
// The contents of this file are subject to the Mozilla Public License
// Version 1.1 (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at
// http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
// License for the specific language governing rights and limitations
// under the License.
//
@kapkaev
kapkaev / The Technical Interview Cheat Sheet.md
Created September 8, 2016 04:32 — forked from tsiege/The Technical Interview Cheat Sheet.md
This is my technical interview cheat sheet. Feel free to fork it or do whatever you want with it. PLEASE let me know if there are any errors or if anything crucial is missing. I will add more links soon.

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

  • Stores data elements based on an sequential, most commonly 0 based, index.
  • Based on tuples from set theory.