mhamza15 · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026
diff --git a/changelog/25.0/25.0.0/summary.md b/changelog/25.0/25.0.0/summary.md
@@ -10,6 +10,7 @@
     - **[New Support](#new-support)**
         - [VTOrc failover of an unreachable primary `vttablet` via replica quorum](#vtorc-quorum-unreachable-primary)
     - **[Breaking Changes](#breaking-changes)**
+        - [`glog` logging removed](#glog-removed)
         - [`--watch-replication-stream` flag removed](#vttablet-watch-replication-stream-removed)
         - [VRLog feature removed](#vttablet-vrlog-removed)
         - [Snapshot Topology feature removed](#vtorc-snapshot-topology-removed)
@@ -113,6 +114,29 @@ See [#19918](https://github.com/vitessio/vitess/issues/19918).
 
 ### <a id="breaking-changes"/>Breaking Changes</a>
 
+#### <a id="glog-removed"/>`glog` logging removed</a>
+
+Vitess now uses structured logging exclusively. The deprecated `glog` backend, its command-line flags,
+`log.Flush`, and `log.V` have been removed.
+
+The following flags have been removed from all binaries.
+
+- `--log-structured`
+- `--log-rotate-max-size`
+- `--logtostderr`, `--alsologtostderr`, `--stderrthreshold`
+- `--log_dir`, `--log_link`, `--log_backtrace_at`
+- `--v`, `--vmodule`, `--logbuflevel`
+- `--keep-logs`, `--keep-logs-by-mtime`, `--purge-logs-interval`
+
+In `vtctldclient`, `-v` is now the shorthand for `--version`, matching the other binaries.
+
+**Migration**: remove the flags above from startup arguments. Use `--log-level=debug` for debug logs and
+`--log-format=text` for human-readable output. Logs are written to stderr, so redirect or collect stderr to keep them
+in files.
+
+**Impact**: binaries will fail to start when passed a removed logging flag. Go callers must replace `log.V` with
+`log.Debug` and remove calls to `log.Flush`.
+
 #### <a id="vttablet-watch-replication-stream-removed"/>`--watch-replication-stream` flag removed</a>
 
 The deprecated `--watch-replication-stream` VTTablet flag has been removed.

@@ -30,7 +30,6 @@ vtctld \
  -service-map 'grpc-vtctl' \
  -backup-storage-implementation file \
  -file-backup-storage-root $VTDATAROOT/backups \
- -log_dir $VTDATAROOT/tmp \
  -port $vtctld_web_port \
  -grpc-port $grpc_port \
  -pid-file $VTDATAROOT/tmp/vtctld.pid \

@@ -41,7 +41,6 @@ echo "  - Tablet listens on http://$hostname:$port"
 # shellcheck disable=SC2086
 vttablet \
  $TOPOLOGY_FLAGS \
- -log_dir $VTDATAROOT/tmp \
  -log-queries-to-file $VTDATAROOT/tmp/$tablet_logfile \
  -tablet-path $alias \
  -tablet-hostname "$hostname" \

diff --git a/examples/common/backup-scripts/mysqlctl-up.sh b/examples/common/backup-scripts/mysqlctl-up.sh
@@ -36,7 +36,6 @@ if [ -d $VTDATAROOT/$tablet_dir ]; then
 fi
 
 mysqlctl \
- --log_dir $VTDATAROOT/tmp \
  --tablet-uid $uid \
  --mysql-port $mysql_port \
  $action

diff --git a/examples/common/backup-scripts/vtadmin-up.sh b/examples/common/backup-scripts/vtadmin-up.sh
@@ -39,8 +39,6 @@ vtadmin \
   --tracer "opentelemetry" \
   --grpc-tracing \
   --http-tracing \
-  --logtostderr \
-  --alsologtostderr \
   --rbac \
   --rbac-config="${script_dir}/../vtadmin/rbac.yaml" \
   --cluster "id=${cluster_name},name=${cluster_name},discovery=staticfile,discovery-staticfile-path=${script_dir}/../vtadmin/discovery.json,tablet-fqdn-tmpl=http://{{ .Tablet.Hostname }}:15{{ .Tablet.Alias.Uid }},schema-cache-default-expiration=1m" \

diff --git a/examples/common/backup-scripts/vtctld-up.sh b/examples/common/backup-scripts/vtctld-up.sh
@@ -27,7 +27,6 @@ vtctld \
  --service-map 'grpc-vtctl,grpc-vtctld' \
  --backup-storage-implementation file \
  --file-backup-storage-root $VTDATAROOT/backups \
- --log_dir $VTDATAROOT/tmp \
  --port $vtctld_web_port \
  --grpc-port $grpc_port \
  --pid-file $VTDATAROOT/tmp/vtctld.pid \

diff --git a/examples/common/backup-scripts/vtgate-up.sh b/examples/common/backup-scripts/vtgate-up.sh
@@ -28,7 +28,6 @@ echo "Starting vtgate..."
 # shellcheck disable=SC2086
 vtgate \
   $TOPOLOGY_FLAGS \
-  --log_dir $VTDATAROOT/tmp \
   --log-queries-to-file $VTDATAROOT/tmp/vtgate_querylog.txt \
   --port $web_port \
   --grpc-port $grpc_port \

diff --git a/examples/common/backup-scripts/vtorc-up.sh b/examples/common/backup-scripts/vtorc-up.sh
@@ -10,8 +10,6 @@ port=16000
 echo "Starting vtorc..."
 vtorc \
   $TOPOLOGY_FLAGS \
-  --logtostderr \
-  --alsologtostderr \
   --config-path="${script_dir}/../vtorc/" \
   --config-name="config.yaml" \
   --config-type="yml" \

diff --git a/examples/common/backup-scripts/vttablet-up.sh b/examples/common/backup-scripts/vttablet-up.sh
@@ -43,7 +43,6 @@ echo "Topology flags at start of backup vttablet, after explicitly setting: $TOP
 # shellcheck disable=SC2086
 vttablet \
  $TOPOLOGY_FLAGS \
- --log_dir $VTDATAROOT/tmp \
  --log-queries-to-file $VTDATAROOT/tmp/$tablet_logfile \
  --tablet-path $alias \
  --tablet-hostname "$tablet_hostname" \

diff --git a/examples/common/backup-scripts/zk-down.sh b/examples/common/backup-scripts/zk-down.sh
@@ -21,6 +21,5 @@ source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 # Stop ZooKeeper servers.
 echo "Stopping zk servers..."
 for zkid in $zkids; do
-  zkctl --zk.myid $zkid --zk.cfg $zkcfg --log_dir $VTDATAROOT/tmp shutdown
+  zkctl --zk.myid $zkid --zk.cfg $zkcfg shutdown
 done
-
diff --git a/examples/common/backup-scripts/zk-up.sh b/examples/common/backup-scripts/zk-up.sh
@@ -31,7 +31,7 @@ for zkid in $zkids; do
     echo "    $VTDATAROOT/$zkdir"
     action='start'
   fi
-  zkctl --zk.myid $zkid --zk.cfg $zkcfg --log_dir $VTDATAROOT/tmp $action \
+  zkctl --zk.myid $zkid --zk.cfg $zkcfg $action \
     > $VTDATAROOT/tmp/zkctl_$zkid.out 2>&1 &
   pids[$zkid]=$!
 done

diff --git a/examples/common/scripts/vtadmin-up.sh b/examples/common/scripts/vtadmin-up.sh
@@ -39,8 +39,6 @@ vtadmin \
   --tracer "opentelemetry" \
   --grpc-tracing \
   --http-tracing \
-  --logtostderr \
-  --alsologtostderr \
   --rbac \
   --rbac-config="${script_dir}/../vtadmin/rbac.yaml" \
   --cluster "id=${cluster_name},name=${cluster_name},discovery=staticfile,discovery-staticfile-path=${script_dir}/../vtadmin/discovery.json,tablet-fqdn-tmpl=http://{{ .Tablet.Hostname }}:15{{ .Tablet.Alias.Uid }},schema-cache-default-expiration=1m" \

diff --git a/examples/common/scripts/vtorc-up.sh b/examples/common/scripts/vtorc-up.sh
@@ -10,8 +10,6 @@ port=16000
 echo "Starting vtorc..."
 vtorc \
   $TOPOLOGY_FLAGS \
-  --logtostderr \
-  --alsologtostderr \
   --config-path="${script_dir}/../vtorc/" \
   --config-name="config.yaml" \
   --config-type="yml" \

@@ -31,7 +31,7 @@ kubectl apply -f 101_initial_cluster.yaml
 # VTAdmin's UI will be available at http://localhost:14000/
 ./pf.sh &
 alias mysql="mysql -h 127.0.0.1 -P 15306 -u user"
-alias vtctldclient="vtctldclient --server localhost:15999 --alsologtostderr"
+alias vtctldclient="vtctldclient --server localhost:15999"
 vtctldclient ApplySchema --sql="$(cat ../common/create_commerce_schema.sql)" commerce
 vtctldclient ApplyVSchema --vschema="$(cat ../common/vschema_commerce_initial.json)" commerce
 

@@ -8,7 +8,7 @@ kubectl port-forward -n example --address localhost "$(kubectl get service -n ex
 process_id3=$!
 sleep 2
 echo "You may point your browser to http://localhost:15000, use the following aliases as shortcuts:"
-echo 'alias vtctldclient="vtctldclient --server=localhost:15999 --logtostderr"'
+echo 'alias vtctldclient="vtctldclient --server=localhost:15999"'
 echo 'alias mysql="mysql -h 127.0.0.1 -P 15306 -u user"'
 echo "Hit Ctrl-C to stop the port forwards"
 wait $process_id1

@@ -31,7 +31,6 @@ require (
 	github.com/gammazero/deque v1.2.1
 	github.com/go-sql-driver/mysql v1.10.1
 	github.com/go-viper/mapstructure/v2 v2.5.0
-	github.com/golang/glog v1.2.5
 	github.com/golang/snappy v1.0.0
 	github.com/google/go-cmp v0.7.0
 	github.com/google/go-containerregistry v0.22.1

@@ -197,8 +197,6 @@ github.com/goccy/go-json v0.10.6/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PU
 github.com/godbus/dbus/v5 v5.2.2 h1:TUR3TgtSVDmjiXOgAAyaZbYmIeP3DPkld3jgKGV8mXQ=
 github.com/godbus/dbus/v5 v5.2.2/go.mod h1:3AAv2+hPq5rdnr5txxxRwiGjPXamgoIHgz9FPBfOp3c=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
-github.com/golang/glog v1.2.5 h1:DrW6hGnjIhtvhOIiAKT6Psh/Kd/ldepEa81DKeiRJ5I=
-github.com/golang/glog v1.2.5/go.mod h1:6AhwSGph0fcJtXVM/PEHPqZlFeoLxhs7/t5UDAwmO+w=
 github.com/golang/mock v1.6.0/go.mod h1:p6yTPP+5HYm5mzsMV8JkE6ZKdX+/wYM6Hr+LicevLPs=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=

@@ -33,7 +33,6 @@ var Init = &cobra.Command{
 	Long: "Bootstraps a new `mysqld` instance, initializes its data directory, and starts the instance.\n" +
 		"The MySQL version and flavor will be auto-detected, with a minimal configuration file applied.",
 	Example: `mysqlctl \
-	--alsologtostderr \
 	--tablet-uid 101 \
 	--mysql-port 12345 \
 	init`,

@@ -30,7 +30,6 @@ var InitConfig = &cobra.Command{
 	Long: "Bootstraps the configuration for a new `mysqld` instance and initializes its data directory.\n" +
 		"This command is the same as `init` except the `mysqld` server will not be started.",
 	Example: `mysqlctl \
-	--alsologtostderr \
 	--tablet-uid 101 \
 	--mysql-port 12345 \
 	init_config`,

@@ -31,7 +31,6 @@ var ReinitConfig = &cobra.Command{
 	Long: "Regenerate new configuration files for an existing `mysqld` instance (generating new server_id and server_uuid values).\n" +
 		"This could be helpful to revert configuration changes, or to pick up changes made to the bundled config in newer Vitess versions.",
 	Example: `mysqlctl \
-	--alsologtostderr \
 	--tablet-uid 101 \
 	--mysql-port 12345 \
 	reinit_config`,

@@ -32,9 +32,8 @@ var Shutdown = &cobra.Command{
 	Short: "Shuts down mysqld, without removing any files.",
 	Long: "Stop a `mysqld` instance that was previously started with `init` or `start`.\n\n" +
 		"For large `mysqld` instances, you may need to extend the `wait-time` to shutdown cleanly.",
-	Example: `mysqlctl --tablet-uid 101 --alsologtostderr shutdown`,
-	Args:    cobra.NoArgs,
-	RunE:    commandShutdown,
+	Args: cobra.NoArgs,
+	RunE: commandShutdown,
 }
 
 var shutdownArgs = struct {

@@ -29,12 +29,11 @@ import (
 )
 
 var Start = &cobra.Command{
-	Use:     "start",
-	Short:   "Starts mysqld on an already 'init'-ed directory.",
-	Long:    "Resume an existing `mysqld` instance that was previously bootstrapped with `init` or `init_config`",
-	Example: `mysqlctl --tablet-uid 101 --alsologtostderr start`,
-	Args:    cobra.NoArgs,
-	RunE:    commandStart,
+	Use:   "start",
+	Short: "Starts mysqld on an already 'init'-ed directory.",
+	Long:  "Resume an existing `mysqld` instance that was previously bootstrapped with `init` or `init_config`",
+	Args:  cobra.NoArgs,
+	RunE:  commandStart,
 }
 
 var startArgs = struct {

@@ -34,9 +34,8 @@ var Teardown = &cobra.Command{
 		"This is a destructive operation.\n" +
 		"{{</ warning >}}\n\n" +
 		"Shuts down a `mysqld` instance and removes its data directory.",
-	Example: `mysqlctl --tablet-uid 101 --alsologtostderr teardown`,
-	Args:    cobra.NoArgs,
-	RunE:    commandTeardown,
+	Args: cobra.NoArgs,
+	RunE: commandTeardown,
 }
 
 var teardownArgs = struct {

@@ -63,7 +63,6 @@ var (
 			"{{</ warning>}}\n\n" +
 			"To enable communication with a `vttablet`, the server must be configured to receive gRPC messages on a unix domain socket.",
 		Example: `mysqlctld \
-	--log_dir=${VTDATAROOT}/logs \
 	--tablet-uid=100 \
 	--mysql-port=17100 \
 	--socket-file=/path/to/socket-file`,

@@ -19,9 +19,7 @@ package cmd
 import (
 	"github.com/spf13/cobra"
 
-	_flag "vitess.io/vitess/go/internal/flag"
 	"vitess.io/vitess/go/vt/log"
-	"vitess.io/vitess/go/vt/logutil"
 )
 
 var configFile string
@@ -31,14 +29,10 @@ func Main() *cobra.Command {
 		Use:  "rulesctl",
 		Args: cobra.NoArgs,
 		PreRunE: func(cmd *cobra.Command, args []string) error {
-			_flag.TrickGlog()
-
 			if err := log.Init(cmd.Flags()); err != nil {
 				return err
 			}
 
-			logutil.PurgeLogs()
-
 			return nil
 		},
 		Run: func(cmd *cobra.Command, _ []string) { cmd.Help() },

@@ -22,7 +22,6 @@ import (
 	"vitess.io/vitess/go/acl"
 	"vitess.io/vitess/go/cmd/rulesctl/cmd"
 	vtlog "vitess.io/vitess/go/vt/log"
-	"vitess.io/vitess/go/vt/logutil"
 	"vitess.io/vitess/go/vt/servenv"
 	"vitess.io/vitess/go/vt/utils"
 )
@@ -31,7 +30,6 @@ func main() {
 	rootCmd := cmd.Main()
 	rootCmd.SetGlobalNormalizationFunc(utils.NormalizeUnderscoresToDashes)
 	vtlog.RegisterFlags(rootCmd.PersistentFlags())
-	logutil.RegisterFlags(rootCmd.PersistentFlags())
 	acl.RegisterFlags(rootCmd.PersistentFlags())
 	servenv.RegisterMySQLServerFlags(rootCmd.PersistentFlags())
 	if err := rootCmd.Execute(); err != nil {

@@ -17,18 +17,15 @@ limitations under the License.
 package main
 
 import (
-	"flag"
 	"fmt"
 	"io"
 	"os"
 	"time"
 
 	"github.com/spf13/cobra"
 
-	_flag "vitess.io/vitess/go/internal/flag"
 	"vitess.io/vitess/go/trace"
 	"vitess.io/vitess/go/vt/log"
-	"vitess.io/vitess/go/vt/logutil"
 	"vitess.io/vitess/go/vt/servenv"
 	"vitess.io/vitess/go/vt/utils"
 	"vitess.io/vitess/go/vt/vtadmin"
@@ -61,14 +58,10 @@ var (
 	rootCmd = &cobra.Command{
 		Use: "vtadmin",
 		PreRunE: func(cmd *cobra.Command, args []string) error {
-			_flag.TrickGlog()
-
 			if err := log.Init(cmd.Flags()); err != nil {
 				return err
 			}
 
-			logutil.PurgeLogs()
-
 			if opts.EnableTracing || httpOpts.EnableTracing {
 				startTracing(cmd)
 			}
@@ -220,23 +213,8 @@ func registerFlags() {
 		"Note: any whitespace characters are replaced with hyphens."
 	rootCmd.Flags().StringVar(&cacheRefreshKey, "cache-refresh-key", "vt-cache-refresh", cacheRefreshHelp)
 
-	// Structured logging flags.
 	log.RegisterFlags(rootCmd.Flags())
 
-	// glog flags, no better way to do this
-	rootCmd.Flags().AddGoFlag(flag.Lookup("v"))
-	rootCmd.Flags().AddGoFlag(flag.Lookup("logtostderr"))
-	rootCmd.Flags().AddGoFlag(flag.Lookup("alsologtostderr"))
-	rootCmd.Flags().AddGoFlag(flag.Lookup("stderrthreshold"))
-	rootCmd.Flags().AddGoFlag(flag.Lookup("log_dir"))
-
-	const deprecationMsg = "glog and its flags have been deprecated, use the default structured logging instead (\"--log-structured\")"
-	rootCmd.Flags().MarkDeprecated("v", deprecationMsg)
-	rootCmd.Flags().MarkDeprecated("logtostderr", deprecationMsg)
-	rootCmd.Flags().MarkDeprecated("alsologtostderr", deprecationMsg)
-	rootCmd.Flags().MarkDeprecated("stderrthreshold", deprecationMsg)
-	rootCmd.Flags().MarkDeprecated("log_dir", deprecationMsg)
-
 	servenv.RegisterMySQLServerFlags(rootCmd.Flags())
 
 	// Register TLS flags for gRPC connections to vtctld

@@ -166,7 +166,6 @@ func run(cmd *cobra.Command, args []string) error {
 	writer := logutil.NewLoggerWriter(logger)
 	cmd.SetOut(writer)
 	cmd.SetErr(writer)
-	_ = cmd.Flags().Set("logtostderr", "true")
 
 	servenv.Init()
 

@@ -168,8 +168,6 @@ func run(cmd *cobra.Command, args []string) error {
 }
 
 func _run(cmd *cobra.Command, args []string) (*results, error) {
-	logutil.PurgeLogs()
-
 	if maxSeqID > minSeqID {
 		go func() {
 			if useRandom {

@@ -177,10 +177,6 @@ func run(cmd *cobra.Command, args []string) (err error) {
 
 	cmd.Flags().Set("cells-to-watch", strings.Join(tpb.Cells, ","))
 
-	if f := cmd.Flags().Lookup("log_dir"); f != nil && !f.Changed {
-		cmd.Flags().Set("log_dir", "$VTDATAROOT/tmp")
-	}
-
 	env, err = vtenv.New(vtenv.Options{
 		MySQLServerVersion: servenv.MySQLServerVersion(),
 		TruncateUILen:      servenv.TruncateUILen,

@@ -30,7 +30,6 @@ import (
 
 	"vitess.io/vitess/go/trace"
 	"vitess.io/vitess/go/vt/log"
-	"vitess.io/vitess/go/vt/logutil"
 	"vitess.io/vitess/go/vt/servenv"
 	"vitess.io/vitess/go/vt/topo"
 	"vitess.io/vitess/go/vt/utils"
@@ -119,7 +118,6 @@ connect directly to the topo server(s).`, useInternalVtctld),
 				return fmt.Errorf("failed to initialize vtenv: %w", err)
 			}
 
-			logutil.PurgeLogs()
 			traceCloser = trace.StartTracing("vtctldclient")
 			client, err = getClientForCommand(cmd)
 			ctx := cmd.Context()