vasanthk

System Design 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?

nsabharwal

ambari-server stop
ambari-agent stop
pkill -9 java
#################################
# Remove Packages
################################

yum  -y remove ambari-\*
yum -y remove hcatalog\* 
yum -y remove hive\*

kapkaev

#!/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|

michellesanver

############################## Network And HTTP ###############################

# Elasticsearch, by default, binds itself to the 0.0.0.0 address, and listens
# on port [9200-9300] for HTTP traffic and on port [9300-9400] for node-to-node
# communication. (the range means that if the port is busy, it will automatically
# try the next port).

# Set the bind address specifically (IPv4 or IPv6):
#
# network.bind_host: 192.168.0.1

GaryRogers

Setting up InfluxDB on CentOS/RHEL

The InfluxDB Docs give you a very brief overview of installing InfluxDB on a host. It boils down to 'here's the RPM, install it.' That's fine for looking at the software, but you'll probably want to adjust the configuration a bit for a production environment.

Basic Install

https://influxdb.com/docs/v0.9/introduction/installation.html

Config changes

Modify /etc/opt/influxdb/influxdb.conf

theskumar

# -*- coding: utf-8 -*-
''' Generates database schema graph from a relational database.
Usages:
Add database configuation in this file and then
python app.py

Note: You must have your latest database schema in the database
engine you are running against.
'''
from __future__ import unicode_literals, absolute_import

ralph-tice

A little background on my context:

We run multiple Solr JVMs per box, which live in directories like:

/mnt/solr_8983
/mnt/solr_8984
/mnt/solr_8985
...
/mnt/solr_${PORT}

wmealing

To limit a CPU to a certain C-state, you can pass the processor.max_cstate=X option in the kernel line of /boot/grub/grub.conf.

Here we limit the system to only C-State 1:

    kernel /vmlinuz-2.6.18-371.1.2.el5 ... processor.max_cstate=1

On some systems, the kernel can override the BIOS setting, and the parameter intel_idle.max_cstate=0 may be required to ensure sleep states are not entered:

tjake

### DML ###

# Keyspace Name
keyspace: stresscql

# The CQL for creating a keyspace (optional if it already exists)
keyspace_definition: |
  CREATE KEYSPACE stresscql WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1};

# Table name

prathik

alias showalias='cat ~/.bash_aliases'

#Type ma <aliasname> in a directory and it will create an alias to cd into that directory
makeAlias()
{
        curDir=`pwd`
        echo "alias $1='cd $curDir'" >> ~/.bash_aliases
        source ~/.bashrc
}