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postgresqlgopostgresql-9.5libpq

golang postgres too many connections error


I am new to Golang/Postgres and I am doing some testing and getting an pq: sorry, too many clients already error . My postgres instance is set to a max of 100 connections and I am getting that error in this code

    for i := 0; i < 10000; i++ {
    profile_id = profile_id+1
    on, err := db.Query("insert into streams (post,profile_id,created_on) values ($1,$2,$3)", post, profile_id, created_on)
    defer on.Close()

    if err != nil {
        fmt.Fprintln(w, "-1")
        log.Fatal(err)
    }
}

I can usually get in about 60 to 70 inserts then I get that error . All the connections are coming from that one sample in for For loop . What can I be doing wrong, here is my full code . As far as I know 1 connection can hold many different queries so I don't know why it is only giving me 60 to 70 inserts then get the error .

func Insert_Stream(w http.ResponseWriter, r *http.Request) {


wg := sync.WaitGroup{}
wg.Add(1)


go func(){
    defer wg.Done()

db, err := sql.Open("postgres", Postgres_Connect)
if err != nil {
    log.Fatal(err)
    println(err)

}
defer db.Close()

r.ParseForm()
post := r.FormValue("post")
profile_id,err := strconv.Atoi(r.FormValue("profile_id"))
created_on := time.Now()
for i := 0; i < 10000; i++ {
    profile_id = profile_id+1
    on, err := db.Query("insert into streams (post,profile_id,created_on) values ($1,$2,$3)", post, profile_id)
    defer on.Close()

    if err != nil {
        fmt.Fprintln(w, "-1")
        log.Fatal(err)
    }
}

fmt.Fprintln(w, "1")

}()
wg.Wait()

}

I am essentially inserting 10,000 records into the database with a different profile ID for testing .


Solution

  • DO NOT use defer in loop. Because it will execute when function returns.