chore: add additional info for host metrics onboarding

pkg/query-service/app/clickhouseReader/reader.go

@@ -3384,6 +3384,17 @@ func (r *ClickHouseReader) GetMetricMetadata(ctx context.Context, metricName, se
 	}, nil
 }
 
+// GetCountOfThings returns the count of things in the query
+// This is a generic function that can be used to check if any data exists for a given query
+func (r *ClickHouseReader) GetCountOfThings(ctx context.Context, query string) (uint64, error) {
+	var count uint64
+	err := r.db.QueryRow(ctx, query).Scan(&count)
+	if err != nil {
+		return 0, err
+	}
+	return count, nil
+}
+
 func (r *ClickHouseReader) GetLatestReceivedMetric(
 	ctx context.Context, metricNames []string,
 ) (*model.MetricStatus, *model.ApiError) {

pkg/query-service/app/inframetrics/hosts.go

@@ -2,13 +2,15 @@ package inframetrics
 
 import (
 	"context"
+	"fmt"
 	"math"
 	"sort"
 	"strings"
 	"time"
 
 	"go.signoz.io/signoz/pkg/query-service/app/metrics/v4/helpers"
 	"go.signoz.io/signoz/pkg/query-service/common"
+	"go.signoz.io/signoz/pkg/query-service/constants"
 	"go.signoz.io/signoz/pkg/query-service/interfaces"
 	"go.signoz.io/signoz/pkg/query-service/model"
 	v3 "go.signoz.io/signoz/pkg/query-service/model/v3"
@@ -310,6 +312,45 @@ func (h *HostsRepo) getTopHostGroups(ctx context.Context, req model.HostListRequ
 	return topHostGroups, allHostGroups, nil
 }
 
+func (h *HostsRepo) DidSendHostMetricsData(ctx context.Context, req model.HostListRequest) (bool, error) {
+
+	names := []string{}
+	for _, metricName := range metricNamesForHosts {
+		names = append(names, metricName)
+	}
+
+	namesStr := "'" + strings.Join(names, "','") + "'"
+
+	query := fmt.Sprintf("SELECT count() FROM %s.%s WHERE metric_name IN (%s)",
+		constants.SIGNOZ_METRIC_DBNAME, constants.SIGNOZ_TIMESERIES_v4_1DAY_TABLENAME, namesStr)
+
+	count, err := h.reader.GetCountOfThings(ctx, query)
+	if err != nil {
+		return false, err
+	}
+
+	return count > 0, nil
+}
+
+func (h *HostsRepo) IsSendingK8SAgentMetrics(ctx context.Context, req model.HostListRequest) (bool, error) {
+	names := []string{}
+	for _, metricName := range metricNamesForHosts {
+		names = append(names, metricName)
+	}
+	namesStr := "'" + strings.Join(names, "','") + "'"
+
+	query := fmt.Sprintf(`
+	SELECT count()
+	FROM %s.%s
+	WHERE metric_name IN (%s)
+		AND unix_milli >= toUnixTimestamp(now() - INTERVAL 60 MINUTE) * 1000
+		AND JSONExtractString(labels, 'host_name') LIKE '%%-otel-agent%%'`,
+		constants.SIGNOZ_METRIC_DBNAME, constants.SIGNOZ_TIMESERIES_V4_TABLENAME, namesStr)
+
+	count, err := h.reader.GetCountOfThings(ctx, query)
+	return count > 0, err
+}
+
 func (h *HostsRepo) GetHostList(ctx context.Context, req model.HostListRequest) (model.HostListResponse, error) {
 	resp := model.HostListResponse{}
 
@@ -330,6 +371,14 @@ func (h *HostsRepo) GetHostList(ctx context.Context, req model.HostListRequest)
 		resp.Type = model.ResponseTypeGroupedList
 	}
 
+	// don't fail the request if we can't get these values
+	if sendingK8SAgentMetrics, err := h.IsSendingK8SAgentMetrics(ctx, req); err == nil {
+		resp.IsSendingK8SAgentMetrics = sendingK8SAgentMetrics
+	}
+	if sentAnyHostMetricsData, err := h.DidSendHostMetricsData(ctx, req); err == nil {
+		resp.SentAnyHostMetricsData = sentAnyHostMetricsData
+	}
+
 	step := int64(math.Max(float64(common.MinAllowedStepInterval(req.Start, req.End)), 60))
 
 	query := HostsTableListQuery.Clone()

pkg/query-service/constants/constants.go

@@ -243,6 +243,7 @@ const (
 	SIGNOZ_SPAN_INDEX_LOCAL_TABLENAME          = "signoz_index_v2"
 	SIGNOZ_SPAN_INDEX_V3_LOCAL_TABLENAME       = "signoz_index_v3"
 	SIGNOZ_TIMESERIES_v4_LOCAL_TABLENAME       = "time_series_v4"
+	SIGNOZ_TIMESERIES_V4_TABLENAME             = "distributed_time_series_v4"
 	SIGNOZ_TIMESERIES_v4_6HRS_LOCAL_TABLENAME  = "time_series_v4_6hrs"
 	SIGNOZ_TIMESERIES_v4_1DAY_LOCAL_TABLENAME  = "time_series_v4_1day"
 	SIGNOZ_TIMESERIES_v4_1WEEK_LOCAL_TABLENAME = "time_series_v4_1week"

pkg/query-service/interfaces/interface.go

@@ -107,6 +107,8 @@ type Reader interface {
 	// Query Progress tracking helpers.
 	ReportQueryStartForProgressTracking(queryId string) (reportQueryFinished func(), err *model.ApiError)
 	SubscribeToQueryProgress(queryId string) (<-chan model.QueryProgress, func(), *model.ApiError)
+
+	GetCountOfThings(ctx context.Context, query string) (uint64, error)
 }
 
 type Querier interface {

pkg/query-service/model/infra.go

@@ -37,9 +37,11 @@ type HostListRecord struct {
 }
 
 type HostListResponse struct {
-	Type    ResponseType     `json:"type"`
-	Records []HostListRecord `json:"records"`
-	Total   int              `json:"total"`
+	Type                     ResponseType     `json:"type"`
+	Records                  []HostListRecord `json:"records"`
+	Total                    int              `json:"total"`
+	SentAnyHostMetricsData   bool             `json:"sentAnyHostMetricsData"`
+	IsSendingK8SAgentMetrics bool             `json:"isSendingK8SAgentMetrics"`
 }
 
 func (r *HostListResponse) SortBy(orderBy *v3.OrderBy) {