moraes

package main

import (
	"fmt"
)

type Node struct {
	Value int
}

jboner

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

dspezia

// Change propagateExpire function in db.c as follows:

void propagateExpire(redisDb *db, robj *key) {

    /*     HORRIBLE HACK STARTS HERE  */
    /* robj *argv[2]; */
    robj *argv[3];
    /*     HORRIBLE HACK ENDS HERE  */

    argv[0] = shared.del;

rgreenjr

-- show running queries (pre 9.2)
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query 
FROM pg_stat_activity 
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' 
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(clock_timestamp(), query_start), usename, query 
FROM pg_stat_activity 
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' 

kelvinn

# post_loc.txt contains the json you want to post
# -p means to POST it
# -H adds an Auth header (could be Basic or Token)
# -T sets the Content-Type
# -c is concurrent clients
# -n is the number of requests to run in the test

ab -p post_loc.txt -T application/json -H 'Authorization: Token abcd1234' -c 10 -n 2000 http://example.com/api/v1/locations/

abdullin

This is my response to an email asking about Domain-Driven Design in golang project.

Thank you for getting in touch. Below you will find my thoughts on how golang works with DDD, changing it. This is merely a perception of how things worked out for us in a single project.

That project has a relatively well-known domain. My colleagues on this project are very knowledgeable, thoughtful and invested in quality design. The story spelled out below is a result of countless hours spent discussing and refining the approach.

Conclusions could be very different, if there was a different project, team or a story-teller.

Short story

harlow

Golang Workers / Job Queue

A running example of the code from:

• http://marcio.io/2015/07/handling-1-million-requests-per-minute-with-golang
• http://nesv.github.io/golang/2014/02/25/worker-queues-in-go.html

This gist creates a working example from blog post, and a alternate example using simple worker pool.

TLDR: if you want simple and controlled concurrency use a worker pool.

popravich

The standard names for indexes in PostgreSQL are:

{tablename}_{columnname(s)}_{suffix}

where the suffix is one of the following:

• pkey for a Primary Key constraint;
• key for a Unique constraint;
• excl for an Exclusion constraint;
• idx for any other kind of index;

valyala

Optimizing postgresql table for more than 100K inserts per second

• Create UNLOGGED table. This reduces the amount of data written to persistent storage by up to 2x.
• Set WITH (autovacuum_enabled=false) on the table. This saves CPU time and IO bandwidth on useless vacuuming of the table (since we never DELETE or UPDATE the table).
• Insert rows with COPY FROM STDIN. This is the fastest possible approach to insert rows into table.
• Minimize the number of indexes in the table, since they slow down inserts. Usually an index on time timestamp with time zone is enough.
• Add synchronous_commit = off to postgresql.conf.
• Use table inheritance for fast removal of old data:

ospatil

1. get list of remote tags
  git ls-remote --tags origin

2. get list of local tags
  git tag

3. remove local tag 
  git tag -d <tag name>

4. delete remote tag