mongodb-rust-driver perform poorly on find and get large amount of data compare to go-driver - mongodb

Question

I have a database consist of 85.4k of document with average size of 4kb
I write a simple code in go to find and get over 70k document from the database using mongodb-go-driver
package main
import (
"context"
"log"
"time"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
)
func main() {
localC, _ := mongo.Connect(context.TODO(), options.Client().ApplyURI("mongodb://127.0.0.1:27017/?gssapiServiceName=mongodb"))
localDb := localC.Database("sampleDB")
collect := localDb.Collection("sampleCollect")
localCursor, _ := collect.Find(context.TODO(), JSON{
"deleted": false,
})
log.Println("start")
start := time.Now()
var result []map[string] interface{} = make([]map[string] interface{}, 0)
localCursor.All(context.TODO(), &result)
log.Println(len(result))
log.Println("done")
log.Println(time.Now().Sub(start))
}
Which done in around 20 seconds
2021/03/21 01:36:43 start
2021/03/21 01:36:56 70922
2021/03/21 01:36:56 done
2021/03/21 01:36:56 20.0242869s
After that, I try to implement the similar thing in rust using mongodb-rust-driver
use mongodb::{
bson::{doc, Document},
error::Error,
options::FindOptions,
Client,
};
use std::time::Instant;
use tokio::{self, stream::StreamExt};
#[tokio::main]
async fn main() {
let client = Client::with_uri_str("mongodb://localhost:27017/")
.await
.unwrap();
let db = client.database("sampleDB");
let coll = db.collection("sampleCollect");
let find_options = FindOptions::builder().build();
let cursor = coll
.find(doc! {"deleted": false}, find_options)
.await
.unwrap();
let start = Instant::now();
println!("start");
let results: Vec<Result<Document, Error>> = cursor.collect().await;
let es = start.elapsed();
println!("{}", results.iter().len());
println!("{:?}", es);
}
But it took almost 1 minutes to complete the same task on release build
$ cargo run --release
Finished release [optimized] target(s) in 0.43s
Running `target\release\rust-mongo.exe`
start
70922
51.1356069s
May I know the performance on rust in this case is consider normal or I made some mistake on my rust code and it could be improve?
EDIT
As comment suggested, here is the Example document

Answer 1

The discrepancy here was due to some known bottlenecks in the Rust driver that have since been addressed in the latest beta release (2.0.0-beta.3); so, upgrading your mongodb dependency to use that version should solve the issue.
Re-running your examples with 10k copies of the provided sample document, I now see the Rust one taking ~3.75s and the Go one ~5.75s on my machine.