Reduce memory usage by fixing alignment of fields in structs

.golangci.yml

@@ -44,6 +44,9 @@ linters-settings:
       - name: empty-block
       - name: unreachable-code
       - name: redefines-builtin-id
+  govet:
+    enable:
+      - fieldalignment
 
 linters:
   disable-all: true

internal/app/app.go

@@ -26,21 +26,21 @@ import (
 
 // App is main application structure
 type App struct {
-	state               appState
-	logger              *log.Logger
-	config              *config.Config
+	lostQuorumTime      time.Time
+	externalReplication mysql.IExternalReplication
+	switchHelper        mysql.ISwitchHelper
 	dcs                 dcs.DCS
-	cluster             *mysql.Cluster
-	filelock            *flock.Flock
 	nodeFailedAt        map[string]time.Time
+	filelock            *flock.Flock
 	slaveReadPositions  map[string]string
 	streamFromFailedAt  map[string]time.Time
 	daemonState         *DaemonState
-	daemonMutex         sync.Mutex
 	replRepairState     map[string]*ReplicationRepairState
-	externalReplication mysql.IExternalReplication
-	switchHelper        mysql.ISwitchHelper
-	lostQuorumTime      time.Time
+	cluster             *mysql.Cluster
+	config              *config.Config
+	logger              *log.Logger
+	state               appState
+	daemonMutex         sync.Mutex
 }
 
 // NewApp returns new App. Suddenly.
@@ -2458,7 +2458,7 @@ func (app *App) getNodePositions(activeNodes []string) ([]nodePosition, error) {
 		}
 
 		positionsMutex.Lock()
-		positions = append(positions, nodePosition{host, gtidset, *lag, nc.Priority})
+		positions = append(positions, nodePosition{gtidset, host, *lag, nc.Priority})
 		positionsMutex.Unlock()
 		return nil
 	}, activeNodes)

internal/app/data.go

@@ -81,25 +81,24 @@ var (
 
 // NodeState contains status check performed by some mysync process
 type NodeState struct {
-	CheckBy              string         `json:"check_by"`
 	CheckAt              time.Time      `json:"check_at"`
-	PingOk               bool           `json:"ping_ok"`
-	PingDubious          bool           `json:"ping_dubious"`
+	SemiSyncState        *SemiSyncState `json:"semi_sync_state"`
+	SlaveState           *SlaveState    `json:"slave_state"`
+	MasterState          *MasterState   `json:"master_state"`
+	DaemonState          *DaemonState   `json:"daemon_state"`
+	DiskState            *DiskState     `json:"disk_state"`
+	Error                string         `json:"error"`
+	CheckBy              string         `json:"check_by"`
 	IsMaster             bool           `json:"is_master"`
-	IsReadOnly           bool           `json:"is_readonly"`
-	IsSuperReadOnly      bool           `json:"is_super_readonly"`
-	IsOffline            bool           `json:"is_offline"`
-	IsCascade            bool           `json:"is_cascade"`
 	IsFileSystemReadonly bool           `json:"is_file_system_readonly"`
 	IsLoadingBinlog      bool           `json:"is_loading_binlog"`
-	Error                string         `json:"error"`
-	DiskState            *DiskState     `json:"disk_state"`
-	DaemonState          *DaemonState   `json:"daemon_state"`
-	MasterState          *MasterState   `json:"master_state"`
-	SlaveState           *SlaveState    `json:"slave_state"`
-	SemiSyncState        *SemiSyncState `json:"semi_sync_state"`
-
-	ShowOnlyGTIDDiff bool
+	IsCascade            bool           `json:"is_cascade"`
+	IsOffline            bool           `json:"is_offline"`
+	IsSuperReadOnly      bool           `json:"is_super_readonly"`
+	IsReadOnly           bool           `json:"is_readonly"`
+	PingDubious          bool           `json:"ping_dubious"`
+	PingOk               bool           `json:"ping_ok"`
+	ShowOnlyGTIDDiff     bool
 }
 
 // Last_SQL_Errno codes, that disallow to restart replication
@@ -300,14 +299,14 @@ const (
 
 // Switchover contains info about currently running or scheduled switchover/failover process
 type Switchover struct {
+	InitiatedAt time.Time         `json:"initiated_at"`
+	StartedAt   time.Time         `json:"started_at"`
+	Result      *SwitchoverResult `json:"result"`
 	From        string            `json:"from"`
 	To          string            `json:"to"`
 	Cause       string            `json:"cause"`
 	InitiatedBy string            `json:"initiated_by"`
-	InitiatedAt time.Time         `json:"initiated_at"`
 	StartedBy   string            `json:"started_by"`
-	StartedAt   time.Time         `json:"started_at"`
-	Result      *SwitchoverResult `json:"result"`
 	RunCount    int               `json:"run_count,omitempty"`
 }
 
@@ -337,15 +336,15 @@ func (sw *Switchover) String() string {
 
 // SwitchoverResult contains results of finished/failed switchover
 type SwitchoverResult struct {
-	Ok         bool      `json:"ok"`
-	Error      string    `json:"error"`
 	FinishedAt time.Time `json:"finished_at"`
+	Error      string    `json:"error"`
+	Ok         bool      `json:"ok"`
 }
 
 // Maintenance struct presence means that cluster under manual control
 type Maintenance struct {
-	InitiatedBy  string    `json:"initiated_by"`
 	InitiatedAt  time.Time `json:"initiated_at"`
+	InitiatedBy  string    `json:"initiated_by"`
 	MySyncPaused bool      `json:"mysync_paused"`
 	ShouldLeave  bool      `json:"should_leave"`
 }

internal/app/util.go

@@ -11,8 +11,8 @@ import (
 )
 
 type nodePosition struct {
-	host     string
 	gtidset  gtids.GTIDSet
+	host     string
 	lag      float64
 	priority int64
 }
@@ -194,15 +194,15 @@ func getDubiousHAHosts(clusterState map[string]*NodeState) []string {
 
 func getNodeStatesInParallel(hosts []string, getter func(string) (*NodeState, error), logger *log.Logger) (map[string]*NodeState, error) {
 	type result struct {
-		name  string
-		state *NodeState
 		err   error
+		state *NodeState
+		name  string
 	}
 	results := make(chan result, len(hosts))
 	for _, host := range hosts {
 		go func(host string) {
 			state, err := getter(host)
-			results <- result{host, state, err}
+			results <- result{err, state, host}
 		}(host)
 	}
 	clusterState := make(map[string]*NodeState)