DM: Support MySQL 8.4

[dveeden]

Is your feature request related to a problem?

MySQL 8.4 removes things like SHOW MASTER STATUS. These have been replaced with SHOW BINARY LOG STATUS.

So things like this needs an update:

tiflow/dm/pkg/conn/utils.go

Line 112 in be15534

rows, err := db.QueryContext(ctx, `SHOW MASTER STATUS`)

tiflow/dm/pkg/conn/db.go

Line 108 in be15534

rows, err := db.QueryContext(ctx, `SHOW SLAVE HOSTS`)

This should be done without breaking compatibility with MySQL 8.0, 5.7 or MariaDB

This depends on:

• dumpling: Support for MySQL 8.4.0 tidb#53082
• Support MySQL 8.4.0 go-mysql-org/go-mysql#866

Describe the feature you'd like

.

Describe alternatives you've considered

No response

Teachability, Documentation, Adoption, Migration Strategy

No response

[dveeden]

/area dm
/label compatibility

[ti-chi-bot]

@dveeden: The label(s) compatibility cannot be applied. These labels are supported: duplicate, bug-from-internal-test, bug-from-user, ok-to-test, needs-ok-to-test, affects-5.4, affects-6.1, affects-6.5, affects-7.1, affects-7.5, affects-8.1, may-affects-5.4, may-affects-6.1, may-affects-6.5, may-affects-7.1, may-affects-7.5, may-affects-8.1, needs-cherry-pick-release-5.4, needs-cherry-pick-release-6.1, needs-cherry-pick-release-6.5, needs-cherry-pick-release-7.1, needs-cherry-pick-release-7.5, needs-cherry-pick-release-8.1, question, release-blocker, wontfix, MariaDB.

In response to this:

/area dm
/label compatibility

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[dveeden]

cc @lance6716

[lance6716]

/assign @lyzx2001

[dveeden]

Related: go-mysql-org/go-mysql#866

[dveeden]

Maybe something like this:

diff --git a/dm/pkg/conn/utils.go b/dm/pkg/conn/utils.go
index df18fe876..3bef16ec0 100644
--- a/dm/pkg/conn/utils.go
+++ b/dm/pkg/conn/utils.go
@@ -15,6 +15,7 @@ package conn
 
 import (
        "context"
+       "database/sql"
        "fmt"
        "math"
        "strconv"
@@ -107,9 +108,15 @@ func GetMasterStatus(ctx *tcontext.Context, db *BaseDB, flavor string) (
                binlogIgnoreDB string
                gtidStr        string
                err            error
+               rows           *sql.Rows
        )
        // need REPLICATION SLAVE privilege
-       rows, err := db.QueryContext(ctx, `SHOW MASTER STATUS`)
+       rows, err = db.QueryContext(ctx, `SHOW BINARY LOG STATUS`)
+       if err != nil {
+               if strings.Contains(err.Error(), "You have an error in your SQL syntax") {
+                       rows, err = db.QueryContext(ctx, `SHOW MASTER STATUS`)
+               }
+       }
        if err != nil {
                err = terror.DBErrorAdapt(err, db.Scope, terror.ErrDBDriverError)
                return binlogName, pos, binlogDoDB, binlogIgnoreDB, gtidStr, err

While there is the notion of a flavor, there isn't really a good/easy way go get the version (e.g. from the "ServerGreeting)" without executing another query. Maybe we should do a SELECT VERSION() once after the connection is established and then store it so we can do if flavor==MySQL && version.Compare(...) {}