Gorm & Postgres Connection reset by peer - postgresql

Question

Context
Currently I have a REST API that manages customer's data in a db. I'm using the following stack:
Go 1.13
github.com/jinzhu/gorm v1.9.1
Postgres 11
I have the following connection settings.
// NewConnection ...
func NewConnection() (*gorm.DB, error) {
config := getConfig()
connStr := "host=xx.xx.xx port=5432 user=chavista-hatter dbname=my-db password=abc sslmode=verify-ca sslrootcert=/path/to/rcert sslcert=/path/to/cert sslkey=/path/to/key connect_timeout=0"
db, err := gorm.Open("postgres", conn)
if err != nil {
return nil, err
}
db.DB().SetMaxOpenConns(25)
db.DB().SetMaxIdleConns(25)
db.DB().SetConnMaxLifetime(5 * time.Minute)
db.SingularTable(true)
if config.LogQueries {
db = db.Debug()
}
return db, nil
}
I get a connection in the main class and inject that connection into a repository class that executes the queries through Gorm (ORM)
Main class
db, err := database.NewConnection()
if err != nil {
panic(fmt.Sprintf("failed to connect database --> %v", err))
}
fmt.Println("database connection established successfully")
defer db.Close()
customerRepo := customer.NewRepository(db)
Repository class
type repository struct {
db *gorm.DB
}
//NewRepository
func NewRepository(db *gorm.DB) Repository {
return &repository{
db: db,
}
}
func (r *repository) Register(customer *models.Customer) (string, error) {
err := r.db.Create(&customer).Error
if err != nil {
return "", err
}
return customer.key, nil
}
Problem
I sending over 500k request (INSERTS) to my db which have 512 connections available and after a few minutes the following error starts to come up repeatedly in postgres log:
unexpected EOF on client connection with an open transaction
could not receive data from client: Connection reset by peer
Any help?

Answer 1

How are you using GetConnection in your code? It's creating a new connection pool every time it's called - ideally you'd only want to call it once, and pass that single connection around wherever it's used.
I would try changing it to this:
var db *gorm.DB
func NewConnection() (*gorm.DB, error) {
if db != nil {
return db, nil
}
config := getConfig()
connStr := "host=xx.xx.xx port=5432 user=chavista-hatter dbname=my-db password=abc sslmode=verify-ca sslrootcert=/path/to/rcert sslcert=/path/to/cert sslkey=/path/to/key connect_timeout=0"
var err error
db, err = gorm.Open("postgres", conn)
if err != nil {
return nil, err
}
db.DB().SetMaxOpenConns(25)
db.DB().SetMaxIdleConns(25)
db.DB().SetConnMaxLifetime(5 * time.Minute)
db.SingularTable(true)
if config.LogQueries {
db = db.Debug()
}
return db, nil
}
and see if it solves the issue.