I'm running into an issue when I set SetMaxOpenConns to something greater than the number of zookeeper nodes available.

I'm not confident whether it is a bug or intentional, though my understanding was that I could create multiple connections to single cluster.

I believe the error occurs here because eindex is out of range.

Example

package main

import (
	"database/sql"
	"fmt"
	"log"
	"strings"
	"sync"

	_ "github.com/factset/go-drill/driver"
)

type AWS struct {
	key    string
	secret string
}

var maxConnections int = 6

func ConnectDrill() (*sql.DB, error) {
	props := []string{
		"zk=localhost:2181,localhost:2182,localhost:2183",
		"cluster=drillbits1",
		"schema=s3",
	}

	db, err := sql.Open("drill", strings.Join(props, ";"))
	if err != nil {
		return nil, err
	}
	if err = db.Ping(); err != nil {
		return nil, err
	}

	db.SetMaxOpenConns(maxConnections)

	return db, nil
}

func query(con *sql.DB, wg *sync.WaitGroup) {
	defer wg.Done()
	rows, err := con.Query("SELECT * FROM sys.drillbits")

	if err != nil {
		log.Panic(err)
	}

	for rows.Next() {
		rows.Scan()
	}
	fmt.Println("queried")
}

func main() {
	var wg sync.WaitGroup

	con, _ := ConnectDrill()

	wg.Add(10)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)
	go query(con, &wg)

	wg.Wait()
}

oroutine 75 [running]:
github.com/factset/go-drill.(*Client).NewConnection(0xc0000f1500, {0xa9c7f0, 0xc000024110})
	/home/john/go/pkg/mod/github.com/factset/[email protected]/client.go:173 +0x475
github.com/JohnCoene/go-drill/driver.(*connector).Connect(0x0?, {0xa9c7f0?, 0xc000024110?})
	/home/john/Golang/src/github.com/JohnCoene/go-drill/driver/connector.go:19 +0x2f
database/sql.(*DB).conn(0xc00020cd00, {0xa9c7f0, 0xc000024110}, 0x1)
	/usr/local/go/src/database/sql/sql.go:1395 +0x782
database/sql.(*DB).query(0x0?, {0xa9c7f0, 0xc000024110}, {0x9c8f44, 0x1b}, {0x0, 0x0, 0x0}, 0x0?)
	/usr/local/go/src/database/sql/sql.go:1732 +0x5d
database/sql.(*DB).QueryContext(0x0?, {0xa9c7f0, 0xc000024110}, {0x9c8f44, 0x1b}, {0x0, 0x0, 0x0})
	/usr/local/go/src/database/sql/sql.go:1710 +0xda
database/sql.(*DB).Query(...)
	/usr/local/go/src/database/sql/sql.go:1728
main.query(0x0?, 0x0?)
	/home/john/Golang/src/github.com/JohnCoene/go-drill/cmd/main.go:42 +0x8c
created by main.main
	/home/john/Golang/src/github.com/JohnCoene/go-drill/cmd/main.go:66 +0x299
exit status 2

shell returned 1

And thanks for making this package!

Hi Team,

I am new to the apache drill and currently I am using the latest factset drill client library for calling the preperedStatement functionality of the sql, where the sql function call to Prepare() and PrepareContext() both are hang up in drill client call https://github.com/factset/go-drill/blob/v1.2.0/client.go#L427 expecting the message on the queryHandleChannel of type queryHandle := make(chan *rpc.CompleteRpcMessage)

Can someone please explain why it is happening, If I have missed something, explain me how we can resolve this issue.

Sample code of the same issue :

`package main

import (
"context"
"database/sql"
"fmt"
"strings"

_ "github.com/factset/go-drill/driver"

)

func main() {
sqlDb := DrillConnect()
var contx = context.Background()
stmt1, err := sqlDb.PrepareContext(contx, "SELECT * FROM dfs./home/ghuchhar/Downloads/apache-drill-1.21.1/sample-data/region.parquet")
if err != nil {
fmt.Println(err.Error())
return
}
res, err := stmt1.Query()
if err != nil {
fmt.Println(err)
}
for res.Next() {
fmt.Println(res.Columns())
}
}

func DrillConnect() *sql.DB {
props := []string{
"host=0.0.0.0",
"port=31010",
}
db, err := sql.Open("drill", strings.Join(props, ";"))
if err != nil {
fmt.Println(err)
return nil
}
if err := db.Ping(); err != nil {
fmt.Println(err)
return nil
}
return db
}`

Thanks in advance.

Dremio added an extension to the Drill RPC protocol to return natively Arrow buffers instead of Drill buffers so that conversion from Drill to Arrow should be unnecessary.

Protocol extension can be found here:
https://github.com/dremio/dremio-oss/blob/3e029da88441df3af7667d13011b7905bf106f1f/protocol/src/main/protobuf/UserCoordRPC.proto#L91