Unfortunately, there are 2 versions of this. The other is here: https://github.com/endolith/waveform-analyzer I intend to either completely combine them or completely separate them, eventually.
Somewhat crude THD+N calculator in Python
Measures the total harmonic distortion plus noise (THD+N) for a given input signal, by guessing the fundamental frequency (finding the peak in the FFT), and notching it out in the frequency domain. This is a THDR
| -module(mnesia_repl_and_frag). | |
| -compile([export_all]). | |
| -record(store, {key, value}). | |
| %% Usage: | |
| %% Start secondary node, at first. Not a typo :-) | |
| %% Then start primary at another node. |
| #!/usr/bin/env python | |
| import sys,csv | |
| for row in csv.reader(sys.stdin): | |
| print "\t".join(row) |
| [general] | |
| fontname=Terminus 9 | |
| selchars=-A-Za-z0-9,./?%&#:_ | |
| scrollback=0 | |
| bgcolor=#00002b2b3636 | |
| bgalpha=65535 | |
| fgcolor=#65657b7b8383 | |
| disallowbold=false | |
| cursorblinks=false | |
| cursorunderline=false |
| MIT License | |
| Copyright (c) 2012 endolith | |
| Permission is hereby granted, free of charge, to any person obtaining a copy | |
| of this software and associated documentation files (the "Software"), to deal | |
| in the Software without restriction, including without limitation the rights | |
| to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
| copies of the Software, and to permit persons to whom the Software is | |
| furnished to do so, subject to the following conditions: |
原題：Dynamo: Amazon’s Highly Available Key-value Store
原文: Amazon's Dynamo - All Things Distributed (PDF Version)
This article is translated by @ono_matope. Please contact me if any problem.
| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| 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 |
L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns
Compress 1K bytes with Zippy ............. 3,000 ns = 3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns = 20 µs
SSD random read ........................ 150,000 ns = 150 µs
Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs
| オリジナルは力武さんの投稿 http://erlang-users.jp/ml/erlang/index.cgi?0::166 | |
| アキュムレータ accumulator | |
| アノテーション annotation | |
| アリティ arity | |
| ー致条件 match specification | |
| 入れ子リスト deep list | |
| インターフェイス interface | |
| エクスポート export |
#Riak Multi DC Repl Cheat Sheet
##Types There are two types of multi data center replication in Riak.
Fullsync
Operation is triggered by connection creation between clusters, running riak-repl start-fullsync on the listener leader, or every fullsync_interval minutes. Relevant app.config settings: