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@leelakrishna
leelakrishna / camel2underscore.scala
Created June 20, 2020 06:41 — forked from sidharthkuruvila/gist:3154845
Utility to functions to convert between camel case and underscore separated names
/**
* Takes a camel cased identifier name and returns an underscore separated
* name
*
* Example:
* camelToUnderscores("thisIsA1Test") == "this_is_a_1_test"
*/
def camelToUnderscores(name: String) = "[A-Z\\d]".r.replaceAllIn(name, {m =>
"_" + m.group(0).toLowerCase()
})
@mzaradzki
mzaradzki / docIndexer_snippet1.js
Created May 29, 2017 09:13
AWS Lambda to index S3 new files in CloudSearch
exports.handler = (event, context, callback) => {
// WARNING :
// This snippet assumes : event.Records[0].eventName == 'ObjectCreated:Put'
// but the ful code deals with both 'ObjectCreated:Put' and 'ObjectRemoved:Delete'
var filename = event.Records[0].s3.object.key;
var bucketname = event.Records[0].s3.bucket.name;
var params = {
@leelakrishna
leelakrishna / introrx.md
Created April 18, 2016 03:40 — forked from staltz/introrx.md
The introduction to Reactive Programming you've been missing
@vasanthk
vasanthk / System Design.md
Last active December 12, 2025 09:39
System Design Cheatsheet

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?
@rmetzger
rmetzger / gist:bcb57a01aa15d9a64cc3
Created August 30, 2015 12:17
Run Apache Flink on a Kerberos secured YARN cluster on CDH 5.3.0
[cloudera@quickstart build-target]$ klist
Ticket cache: FILE:/tmp/krb5cc_501
Default principal: hdfs@CLOUDERA
Valid starting Expires Service principal
08/30/15 05:15:22 08/31/15 05:15:22 krbtgt/CLOUDERA@CLOUDERA
renew until 09/06/15 05:15:22
[cloudera@quickstart build-target]$ export HADOOP_CONF_DIR=/usr/lib/hadoop/etc/hadoop/
[cloudera@quickstart build-target]$ ./bin/yarn-session.sh -n 1
05:15:37,483 INFO org.apache.hadoop.yarn.client.RMProxy - Connecting to ResourceManager at quickstart.cloudera/127.0.0.1:8032
@ryanfitz
ryanfitz / indexAccountsToCloudsearch.js
Created July 17, 2015 18:46
index dynamodb data to cloudsearch using AWS Lambda
var AWS = require('aws-sdk');
exports.handler = function(event, context) {
var cloudsearchdomain = new AWS.CloudSearchDomain({endpoint: 'doc-dev-cinch-accounts-ltmqj5gt5mjb5hg5eyqaf2v5hu.us-east-1.cloudsearch.amazonaws.com'});
var documents = event.Records.map(function(record) {
var data = {id : record.dynamodb.Keys.id.S};
if (record.eventName === 'REMOVE') {
data.type = 'delete'
@staltz
staltz / introrx.md
Last active December 1, 2025 11:31
The introduction to Reactive Programming you've been missing
@avilches
avilches / Sha.java
Created December 21, 2010 16:25
How to encode a hex SHA256 in Java
import java.security.*;
public class Sha {
public static String hash256(String data) throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance("SHA-256");
md.update(data.getBytes());
return bytesToHex(md.digest());
}
public static String bytesToHex(byte[] bytes) {
StringBuffer result = new StringBuffer();
for (byte byt : bytes) result.append(Integer.toString((byt & 0xff) + 0x100, 16).substring(1));
@pauldix
pauldix / gist:7549
Created August 27, 2008 18:11
require 'benchmark'
require 'rubygems'
require 'json'
require 'yaml'
include Benchmark
benchmark_iterations = 1
large_single_dimension_array = [42, 123.123] * 5000
large_single_dimension_hash = {}
10000.times do |i|