yorickdowne

Overview

Syncing an Ethereum node is largely reliant on latency and IOPS, I/O Per Second, of the storage. Budget SSDs will struggle to an extent, and some won't be able to sync at all. IOPS can roughly be used as proxy of / predictor for latency. Measuring latency directly is arguably better.

This document aims to snapshot some known good and known bad models.

The drive lists are ordered by interface and then by capacity and alphabetically by vendor name, not by preference. The lists are not exhaustive at all. @mwpastore linked a filterable spreadsheet in comments that has a far greater variety of drives and their characteristics. Filter it by DRAM yes, NAND Type TLC, Form Factor M.2, and desired capacity.

For size, 4TB is a conservative choice which also supports a Fusaka "supernode". The smaller 2TB drive should last an Ethereum full node until at least sometime 2026, with [pre-merge history expiry](http

ian-whitestone

Presto Specific

• Don’t SELECT *, Specify explicit column names (columnar store)
• Avoid large JOINs (filter each table first)
  • In PRESTO tables are joined in the order they are listed!!
  • Join small tables earlier in the plan and leave larger fact tables to the end
  • Avoid cross joins or 1 to many joins as these can degrade performance
• Order by and group by take time
  • only use order by in subqueries if it is really necessary
• When using GROUP BY, order the columns by the highest cardinality (that is, most number of unique values) to the lowest.

findepi

Source: https://gist.github.com/findepi/04c96f0f60dcc95329f569bb0c44a0cd .

clean build

This should build the project. In case of problems, retry without the -T flag. This is not the fastest way to build the project though. See below.

./mvnw -T1C clean install -DskipTests 

frgomes

// Base64 encode
val text = "This is plaintext."
val bytesEncoded = java.util.Base64.getEncoder.encode(text.getBytes())

// Base64 decode
val textDecoded = new String(java.util.Base64.getDecoder.decode(bytesEncoded))
println(textDecoded)

reagent

Custom HTTP Routing in Go

Basic Routing

Responding to requests via simple route matching is built in to Go's net/http standard library package. Just register the path prefixes and callbacks you want invoked and then call the ListenAndServe to have the default request handler invoked on each request. For example:

package main

import (

ricardo-rossi

#!/bin/bash

### USAGE
###
### ./ElasticSearch.sh 1.7 will install Elasticsearch 1.7
### ./ElasticSearch.sh will fail because no version was specified (exit code 1)
###
### CLI options Contributed by @janpieper
### Check http://www.elasticsearch.org/download/ for latest version of ElasticSearch

typehorror

Flask-SQLAlchemy Caching

The following gist is an extract of the article Flask-SQLAlchemy Caching. It allows automated simple cache query and invalidation of cache relations through event among other features.

Usage

retrieve one object

# pulling one User object

user = User.query.get(1)

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

quake

Blog.where(created_at: 1.week.ago.beginning_of_week..1.week.ago.end_of_week).order(view_counts: :desc).first.subject

masahitojp

import akka.actor.IO._
import akka.actor.{Props, IO, IOManager, Actor, ActorSystem}
import akka.event.Logging
import akka.util.ByteString
import java.net.InetSocketAddress

class TCPEchoServer(port: Int) extends Actor {
  val log = Logging(context.system, this)

  val state = IterateeRef.Map.async[IO.Handle]()(context.dispatcher)