[YCQL] Wrong port sent for NEW_NODE topology change events

[m-iancu]

For each new node, we are actually sending the tserver hostport instead of the CQL one. Therefore, the host/IP is correct, but the port is wrong: typically 9100 (tserver default) instead of 9042 (CQL default).

Some drivers (e.g. the Java driver) were ignoring the port sent in the event anyway and
using the one set in config/constructor of the driver object -- so this was not practically an issue.
But others like Gocql seem to rely on it.

To replicate

1. Install gocql

go get github.com/yugabyte/gocql

2. Copy the code below into a file cql_example.go

package main;

import (
    "fmt"
    "log"
    "time"
    "strconv"

    "github.com/yugabyte/gocql"
)


func main() {

    // Connect to the cluster.
    cluster := gocql.NewCluster("127.0.0.1", "127.0.0.2", "127.0.0.3")

    // Use the same timeout as the Java driver.
    cluster.Timeout = 12 * time.Second

    // Create the session.
    session, _ := cluster.CreateSession()
    defer session.Close()

    // Set up the keyspace and table.
    if err := session.Query("CREATE KEYSPACE IF NOT EXISTS ybdemo").Exec(); err != nil {
        log.Fatal(err)
    }
    fmt.Println("Created keyspace ybdemo")


    if err := session.Query(`DROP TABLE IF EXISTS ybdemo.employee`).Exec(); err != nil {
        log.Fatal(err)
    }
    var createStmt = `CREATE TABLE ybdemo.employee (id int PRIMARY KEY,
                                                           name varchar,
                                                           age int,
                                                           language varchar)`;
    if err := session.Query(createStmt).Exec(); err != nil {
        log.Fatal(err)
    }
    fmt.Println("Created table ybdemo.employee")

    // Insert some rows into the table.
    for i := 0; i < 10000; i++ {
        var insertStmt string = "INSERT INTO ybdemo.employee(id, name, age, language)" +
            " VALUES (" + strconv.Itoa(i) + ", 'John', 35, 'Go')";
        if err := session.Query(insertStmt).Exec(); err != nil {
            log.Fatal(err)
        }
    }

}

3. Start a yb cluster

Use rf-3 and a low refresh interval to ensure we get topology change events often:

./bin/yb-ctl destroy && ./bin/yb-ctl create --rf 3 --tserver_flags="cql_nodelist_refresh_interval_secs=5" --master_flags="tserver_unresponsive_timeout_ms=5000"

4. Now run the app

go run -tags "gocql_debug" cql_example.go

This should output a lot of logging including lines like:

2019/10/14 17:29:27 gocql: handling frame: [topology_change change=NEW_NODE host=127.0.0.2 port=9100]
2019/10/14 17:29:27 gocql: handling frame: [topology_change change=NEW_NODE host=127.0.0.3 port=9100]
2019/10/14 17:29:27 gocql: handling frame: [topology_change change=NEW_NODE host=127.0.0.1 port=9100]
2019/10/14 17:29:27 gocql: handling frame: [topology_change change=NEW_NODE host=127.0.0.1 port=9100]
2019/10/14 17:29:27 gocql: handling frame: [topology_change change=MOVED_NODE host=127.0.0.1 port=9042]

Notice that above NEW_NODE events have the wrong 9100 port while the MOVED_NODE event has the correct 9042 port.

[m-iancu]

Fixed by c5cffa2.