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  1. Go Driver
  2. GODRIVER-987

Pool exhausts with MongoDB v3.0.4

    • Type: Icon: Bug Bug
    • Resolution: Done
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: 1.0.1
    • Component/s: Core API
    • None
    • Environment:
      CentOS 7 & Go 1.11.4 & MongoDB 3.0.4 (mmapv1)

      Pool exhausts after executing some query using limit and Cursor.Next() on MongoDB v3.0.4, version 1.0.0 dosen't have this problem.

      package main
      
      import (
      	"context"
      	"go.mongodb.org/mongo-driver/bson"
      	"go.mongodb.org/mongo-driver/mongo"
      	"go.mongodb.org/mongo-driver/mongo/options"
      	"log"
      	"time"
      )
      
      func main() {
      	opt := options.Client().ApplyURI("mongodb://xxx")
      	opt.SetMaxPoolSize(10) // important
      	client, err := mongo.NewClient(opt)
      
      	ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
      	if err = client.Connect(ctx); err != nil {
      		log.Fatal(err)
      	}
      
      	for i := 0; true; i++ {
      		startTime := time.Now()
      
      		col := client.Database("xxx").Collection("xxx")
      		filter := bson.M{}
      		opt := options.FindOptions{}
      		opt.SetLimit(1) // important
      		ctx, _ = context.WithTimeout(context.Background(), 5*time.Second)
      		cur, err := col.Find(ctx, filter, &opt)
      		if err != nil {
      			log.Fatal(err)
      		}
      		defer cur.Close(ctx)
      		for cur.Next(ctx) {                  // important
      		}
      
      		log.Println(i, time.Since(startTime))
      	}
      }
      
      // output:
      //
      // 2019/04/20 12:05:30 0 1.255561118s
      // 2019/04/20 12:05:30 1 656.780938ms
      // 2019/04/20 12:05:31 2 877.063852ms
      // 2019/04/20 12:05:32 3 1.024375444s
      // 2019/04/20 12:05:33 4 887.392948ms
      // 2019/04/20 12:05:34 5 946.072635ms
      // 2019/04/20 12:05:35 6 1.049663158s
      // 2019/04/20 12:05:36 7 802.969367ms
      // 2019/04/20 12:05:37 8 1.039775024s
      // 2019/04/20 12:05:42 9 5.000851648s
      // 2019/04/20 12:05:47 context deadline exceeded
      

            Assignee:
            kris.brandow@mongodb.com Kristofer Brandow (Inactive)
            Reporter:
            moptym moptym
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            Watchers:
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              Created:
              Updated:
              Resolved: