blockchain – phrasebook

A blockchain is a peer-to-peer network that timestamps records by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work.

In contrast, a distributed ledger is a peer-to-peer network that uses a defined consensus mechanism to prevent modification of an ordered series of time-stamped records. All blockchains are distributed ledgers, but not all distributed ledgers are blockchains.


Peer-to-peer — no central single-point-of-failure
Immutable — records of past transactions
Ever-growing — the chain keeps growing and never shrinks
Double-spend — is a common error to be prevented by blockchain

angular.js jQuery node.js — phrase book

server-side — Node.js is only library designed for server-side use.

web UI — most of the javascript libraries are meant for web UI

cross-browser support — jQuery, Angular

I feel jQuery is more popular than the other javascript libraries.

php-integration? I have seen books dedicated to jQuery+php

DOM — well supported in jQuery

Ajax — well supported in jQuery

data binding — a major feature of Angular.js, not jQuery.

compressed content in a http response

Now I feel an http response may be a zip containing multiple files. The response “body” will be an compressed bytes array. (To avoid confusion, I will call this a “zip” rather than a “file”.) When you parse these bytes, you may see multiple zip entries.

If you assume the entire zip is a single file and try to decompress/deflate it, it might fail. The output may be empty.

The http response also contains useful response headers. One of the headers would be content-type. The gzip and zip types seem to require different parsers.

Fairchild Semicon’s IP traffic priority

Practical insight. Extremely useful to a company economizing on bandwith

Based on packet “protocol” [1], an IP router can give relative priorities to
Priority 1: voip packets
Priority 2: peoplesoft traffic
Priority 3: browser traffic
Proirity 4: lotus notes replication traffic

Lower priority packets are dropped more.

The most important browser traffic is, hold your breath, sales processing[2]. Sales staff use a web interface to process sales data. DB resides on another continent! In a rare but illustrative /incident/, lotus traffic ate into Priority 3 bandwidth and brought sales processing to a grinding slowdown.

As an alternative to a relatively fragile web interface, I suggested async messaging-based sales processing application. No clear answer.

[2] perhaps including but not limited to sales order
[1] packet headers on one layer of the envelopes