diff --git a/internal/metrics/period/entries.go b/internal/metrics/period/entries.go
index d9a5554f..1c9c17e8 100644
--- a/internal/metrics/period/entries.go
+++ b/internal/metrics/period/entries.go
@@ -6,7 +6,7 @@ import (
 )
 
 type Entries[T any] struct {
-	entries  [maxEntries]*T
+	entries  [maxEntries]T
 	index    int
 	count    int
 	interval time.Duration
@@ -16,17 +16,14 @@ type Entries[T any] struct {
 const maxEntries = 100
 
 func newEntries[T any](duration time.Duration) *Entries[T] {
-	interval := duration / maxEntries
-	if interval < time.Second {
-		interval = time.Second
-	}
+	interval := max(duration/maxEntries, time.Second)
 	return &Entries[T]{
 		interval: interval,
 		lastAdd:  time.Now(),
 	}
 }
 
-func (e *Entries[T]) Add(now time.Time, info *T) {
+func (e *Entries[T]) Add(now time.Time, info T) {
 	if now.Sub(e.lastAdd) < e.interval {
 		return
 	}
@@ -38,11 +35,11 @@ func (e *Entries[T]) Add(now time.Time, info *T) {
 	e.lastAdd = now
 }
 
-func (e *Entries[T]) Get() []*T {
+func (e *Entries[T]) Get() []T {
 	if e.count < maxEntries {
 		return e.entries[:e.count]
 	}
-	res := make([]*T, maxEntries)
+	res := make([]T, maxEntries)
 	copy(res, e.entries[e.index:])
 	copy(res[maxEntries-e.index:], e.entries[:e.index])
 	return res
@@ -57,7 +54,7 @@ func (e *Entries[T]) MarshalJSON() ([]byte, error) {
 
 func (e *Entries[T]) UnmarshalJSON(data []byte) error {
 	var v struct {
-		Entries  []*T          `json:"entries"`
+		Entries  []T           `json:"entries"`
 		Interval time.Duration `json:"interval"`
 	}
 	if err := json.Unmarshal(data, &v); err != nil {
diff --git a/internal/metrics/period/handler.go b/internal/metrics/period/handler.go
index 23f8066f..4dc091c9 100644
--- a/internal/metrics/period/handler.go
+++ b/internal/metrics/period/handler.go
@@ -3,6 +3,7 @@ package period
 import (
 	"errors"
 	"net/http"
+	"net/url"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -29,6 +30,7 @@ type ResponseType[AggregateT any] struct {
 //
 // If the request is a websocket request, it serves the data for the given period for every interval.
 func (p *Poller[T, AggregateT]) ServeHTTP(c *gin.Context) {
+	period := Filter(c.Query("period"))
 	query := c.Request.URL.Query()
 
 	if httpheaders.IsWebsocket(c.Request.Header) {
@@ -42,10 +44,10 @@ func (p *Poller[T, AggregateT]) ServeHTTP(c *gin.Context) {
 			interval = minInterval
 		}
 		websocket.PeriodicWrite(c, interval, func() (any, error) {
-			return p.getRespData(c.Request)
+			return p.getRespData(period, query)
 		})
 	} else {
-		data, err := p.getRespData(c.Request)
+		data, err := p.getRespData(period, query)
 		if err != nil {
 			c.Error(apitypes.InternalServerError(err, "failed to get response data"))
 			return
@@ -58,13 +60,11 @@ func (p *Poller[T, AggregateT]) ServeHTTP(c *gin.Context) {
 	}
 }
 
-func (p *Poller[T, AggregateT]) getRespData(r *http.Request) (any, error) {
-	query := r.URL.Query()
-	period := query.Get("period")
+func (p *Poller[T, AggregateT]) getRespData(period Filter, query url.Values) (any, error) {
 	if period == "" {
 		return p.GetLastResult(), nil
 	}
-	rangeData, ok := p.Get(Filter(period))
+	rangeData, ok := p.Get(period)
 	if !ok {
 		return nil, errors.New("invalid period")
 	}
diff --git a/internal/metrics/period/period.go b/internal/metrics/period/period.go
index 601a6df2..3800ff4b 100644
--- a/internal/metrics/period/period.go
+++ b/internal/metrics/period/period.go
@@ -32,7 +32,7 @@ func NewPeriod[T any]() *Period[T] {
 	}
 }
 
-func (p *Period[T]) Add(info *T) {
+func (p *Period[T]) Add(info T) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	now := time.Now()
@@ -41,7 +41,7 @@ func (p *Period[T]) Add(info *T) {
 	}
 }
 
-func (p *Period[T]) Get(filter Filter) ([]*T, bool) {
+func (p *Period[T]) Get(filter Filter) ([]T, bool) {
 	p.mu.RLock()
 	defer p.mu.RUnlock()
 	period, ok := p.Entries[filter]
diff --git a/internal/metrics/period/poller.go b/internal/metrics/period/poller.go
index b881a6ca..95f6be5b 100644
--- a/internal/metrics/period/poller.go
+++ b/internal/metrics/period/poller.go
@@ -17,16 +17,16 @@ import (
 )
 
 type (
-	PollFunc[T any]                                 func(ctx context.Context, lastResult *T) (*T, error)
-	AggregateFunc[T any, AggregateT json.Marshaler] func(entries []*T, query url.Values) (total int, result AggregateT)
-	FilterFunc[T any]                               func(entries []*T, keyword string) (filtered []*T)
+	PollFunc[T any]                                 func(ctx context.Context, lastResult T) (T, error)
+	AggregateFunc[T any, AggregateT json.Marshaler] func(entries []T, query url.Values) (total int, result AggregateT)
+	FilterFunc[T any]                               func(entries []T, keyword string) (filtered []T)
 	Poller[T any, AggregateT json.Marshaler]        struct {
 		name         string
 		poll         PollFunc[T]
 		aggregate    AggregateFunc[T, AggregateT]
 		resultFilter FilterFunc[T]
 		period       *Period[T]
-		lastResult   atomic.Value[*T]
+		lastResult   atomic.Value[T]
 		errs         []pollErr
 	}
 	pollErr struct {
@@ -188,10 +188,10 @@ func (p *Poller[T, AggregateT]) Start() {
 	}()
 }
 
-func (p *Poller[T, AggregateT]) Get(filter Filter) ([]*T, bool) {
+func (p *Poller[T, AggregateT]) Get(filter Filter) ([]T, bool) {
 	return p.period.Get(filter)
 }
 
-func (p *Poller[T, AggregateT]) GetLastResult() *T {
+func (p *Poller[T, AggregateT]) GetLastResult() T {
 	return p.lastResult.Load()
 }