Files
grafana/pkg/services/ngalert/ngalert_test.go
Seunghun Shin c784de6ef5 Alerting: Add compressed periodic save for alert instances (#111803)
What is this feature?

This PR implements compressed periodic save for alert state storage, providing a more efficient alternative to regular periodic saves by grouping alert instances by rule UID and storing them using protobuf and snappy compression. When enabled via the state_compressed_periodic_save_enabled configuration option, the system groups alert instances by their alert rule, compresses each group using protobuf serialization and snappy compression, and processes all rules within a single database transaction at specified intervals instead of syncing after every alert evaluation cycle.

Why do we need this feature?

During discussions in PR #111357, we identified the need for a compressed approach to periodic alert state storage that could further reduce database load beyond the jitter mechanism. While the jitter feature distributes database operations over time, this compressed periodic save approach reduces the frequency of database operations by batching alert state updates at explicitly declared intervals rather than syncing after every alert evaluation cycle.
This approach provides several key benefits:

- Reduced Database Frequency: Instead of frequent sync operations tied to alert evaluation cycles, updates occur only at configured intervals
- Storage Efficiency: Rule-based grouping with protobuf and snappy compression significantly reduces storage requirements

The compressed periodic save complements the existing jitter mechanism by providing an alternative strategy focused on reducing overall database interaction frequency while maintaining data integrity through compression and batching.

Who is this feature for?

- Platform/Infrastructure teams managing large-scale Grafana deployments with high alert cardinality
- Organizations looking to optimize storage costs and database performance for alerting workloads
- Production environments with 1000+ alert rules where database write frequency is a concern
2025-11-07 11:51:48 +01:00

484 lines
16 KiB
Go

package ngalert
import (
"bytes"
"context"
"io"
"math/rand"
"net/http"
"net/http/httptest"
"testing"
"time"
"github.com/gogo/protobuf/proto"
"github.com/golang/snappy"
"github.com/grafana/grafana-plugin-sdk-go/data"
"github.com/grafana/loki/pkg/push"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/testutil"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"github.com/grafana/grafana/pkg/bus"
"github.com/grafana/grafana/pkg/events"
"github.com/grafana/grafana/pkg/infra/db"
"github.com/grafana/grafana/pkg/infra/log"
"github.com/grafana/grafana/pkg/infra/tracing"
"github.com/grafana/grafana/pkg/services/featuremgmt"
"github.com/grafana/grafana/pkg/services/folder"
acfakes "github.com/grafana/grafana/pkg/services/ngalert/accesscontrol/fakes"
"github.com/grafana/grafana/pkg/services/ngalert/eval"
"github.com/grafana/grafana/pkg/services/ngalert/metrics"
"github.com/grafana/grafana/pkg/services/ngalert/models"
"github.com/grafana/grafana/pkg/services/ngalert/state"
history_model "github.com/grafana/grafana/pkg/services/ngalert/state/historian/model"
"github.com/grafana/grafana/pkg/services/ngalert/store"
"github.com/grafana/grafana/pkg/services/ngalert/tests/fakes"
"github.com/grafana/grafana/pkg/setting"
"github.com/grafana/grafana/pkg/util"
)
func Test_subscribeToFolderChanges(t *testing.T) {
getRecordedCommand := func(ruleStore *fakes.RuleStore) []fakes.GenericRecordedQuery {
results := ruleStore.GetRecordedCommands(func(cmd any) (any, bool) {
c, ok := cmd.(fakes.GenericRecordedQuery)
if !ok || c.Name != "IncreaseVersionForAllRulesInNamespaces" {
return nil, false
}
return c, ok
})
var result []fakes.GenericRecordedQuery
for _, cmd := range results {
result = append(result, cmd.(fakes.GenericRecordedQuery))
}
return result
}
orgID := rand.Int63()
folder1 := &folder.Folder{
UID: util.GenerateShortUID(),
Title: "Folder" + util.GenerateShortUID(),
}
folder2 := &folder.Folder{
UID: util.GenerateShortUID(),
Title: "Folder" + util.GenerateShortUID(),
}
gen := models.RuleGen
rules := gen.With(gen.WithOrgID(orgID), gen.WithNamespace(folder1.ToFolderReference())).GenerateManyRef(5)
bus := bus.ProvideBus(tracing.InitializeTracerForTest())
db := fakes.NewRuleStore(t)
db.Folders[orgID] = append(db.Folders[orgID], folder1)
db.PutRule(context.Background(), rules...)
subscribeToFolderChanges(log.New("test"), bus, db)
err := bus.Publish(context.Background(), &events.FolderFullPathUpdated{
Timestamp: time.Now(),
UIDs: []string{folder1.UID, folder2.UID},
OrgID: orgID,
})
require.NoError(t, err)
require.EventuallyWithT(t, func(c *assert.CollectT) {
recordedCommands := getRecordedCommand(db)
require.Len(c, recordedCommands, 1)
require.Equal(c, recordedCommands[0].Params[0].(int64), orgID)
require.ElementsMatch(c, recordedCommands[0].Params[1].([]string), []string{folder1.UID, folder2.UID})
}, time.Second, 10*time.Millisecond, "expected to call db store method but nothing was called")
}
func TestConfigureHistorianBackend(t *testing.T) {
t.Run("fail initialization if invalid backend", func(t *testing.T) {
met := metrics.NewHistorianMetrics(prometheus.NewRegistry(), metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "invalid-backend",
}
ac := &acfakes.FakeRuleService{}
_, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.ErrorContains(t, err, "unrecognized")
})
t.Run("fail initialization if invalid multi-backend primary", func(t *testing.T) {
met := metrics.NewHistorianMetrics(prometheus.NewRegistry(), metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "multiple",
MultiPrimary: "invalid-backend",
}
ac := &acfakes.FakeRuleService{}
_, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.ErrorContains(t, err, "multi-backend target")
require.ErrorContains(t, err, "unrecognized")
})
t.Run("fail initialization if invalid multi-backend secondary", func(t *testing.T) {
met := metrics.NewHistorianMetrics(prometheus.NewRegistry(), metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "multiple",
MultiPrimary: "annotations",
MultiSecondaries: []string{"annotations", "invalid-backend"},
}
ac := &acfakes.FakeRuleService{}
_, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.ErrorContains(t, err, "multi-backend target")
require.ErrorContains(t, err, "unrecognized")
})
t.Run("do not fail initialization if pinging Loki fails", func(t *testing.T) {
met := metrics.NewHistorianMetrics(prometheus.NewRegistry(), metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "loki",
LokiSettings: setting.UnifiedAlertingLokiSettings{
// Should never resolve at the DNS level: https://www.rfc-editor.org/rfc/rfc6761#section-6.4
LokiReadURL: "http://gone.invalid",
LokiWriteURL: "http://gone.invalid",
},
}
ac := &acfakes.FakeRuleService{}
h, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.NotNil(t, h)
require.NoError(t, err)
})
t.Run("Loki backend sends external labels in Record calls", func(t *testing.T) {
var receivedRequest *http.Request
var receivedBody []byte
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
receivedRequest = r
body, _ := io.ReadAll(r.Body)
receivedBody = body
w.WriteHeader(http.StatusNoContent)
}))
defer server.Close()
met := metrics.NewHistorianMetrics(prometheus.NewRegistry(), metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "loki",
LokiSettings: setting.UnifiedAlertingLokiSettings{
LokiReadURL: server.URL,
LokiWriteURL: server.URL,
},
ExternalLabels: map[string]string{
"test_label": "test_value",
"cluster": "prod",
},
}
ac := &acfakes.FakeRuleService{}
h, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.NoError(t, err)
require.NotNil(t, h)
rule := history_model.RuleMeta{
OrgID: 1,
UID: "test-rule-uid",
Group: "test-group",
NamespaceUID: "test-namespace",
Title: "Test Rule",
}
states := []state.StateTransition{
{
PreviousState: eval.Normal,
State: &state.State{
State: eval.Alerting,
Labels: data.Labels{"instance": "test-instance"},
LastEvaluationTime: time.Now(),
},
},
}
errCh := h.Record(context.Background(), rule, states)
err = <-errCh
require.NoError(t, err)
require.NotNil(t, receivedRequest, "Expected HTTP request to be sent to Loki")
require.Contains(t, receivedRequest.URL.Path, "/loki/api/v1/push")
// Loki uses snappy-compressed protobuf encoding
decompressed, err := snappy.Decode(nil, receivedBody)
require.NoError(t, err)
var req push.PushRequest
err = proto.Unmarshal(decompressed, &req)
require.NoError(t, err)
require.Len(t, req.Streams, 1, "Expected exactly one stream")
stream := req.Streams[0]
require.Contains(t, stream.Labels, `test_label="test_value"`)
require.Contains(t, stream.Labels, `cluster="prod"`)
require.Contains(t, stream.Labels, `from="state-history"`)
require.Contains(t, stream.Labels, `orgID="1"`)
})
t.Run("fail initialization if prometheus backend missing datasource UID", func(t *testing.T) {
met := metrics.NewHistorianMetrics(prometheus.NewRegistry(), metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "prometheus",
// Missing PrometheusTargetDatasourceUID
}
ac := &acfakes.FakeRuleService{}
_, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.Error(t, err)
require.ErrorContains(t, err, "datasource UID must not be empty")
})
t.Run("successful initialization of prometheus backend", func(t *testing.T) {
met := metrics.NewHistorianMetrics(prometheus.NewRegistry(), metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "prometheus",
PrometheusMetricName: "test_metric",
PrometheusTargetDatasourceUID: "test-prometheus-uid",
}
ac := &acfakes.FakeRuleService{}
h, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.NotNil(t, h)
require.NoError(t, err)
})
t.Run("emit metric describing chosen backend", func(t *testing.T) {
reg := prometheus.NewRegistry()
met := metrics.NewHistorianMetrics(reg, metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: true,
Backend: "annotations",
}
ac := &acfakes.FakeRuleService{}
h, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.NotNil(t, h)
require.NoError(t, err)
exp := bytes.NewBufferString(`
# HELP grafana_alerting_state_history_info Information about the state history store.
# TYPE grafana_alerting_state_history_info gauge
grafana_alerting_state_history_info{backend="annotations"} 1
`)
err = testutil.GatherAndCompare(reg, exp, "grafana_alerting_state_history_info")
require.NoError(t, err)
})
t.Run("emit special zero metric if state history disabled", func(t *testing.T) {
reg := prometheus.NewRegistry()
met := metrics.NewHistorianMetrics(reg, metrics.Subsystem)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
cfg := setting.UnifiedAlertingStateHistorySettings{
Enabled: false,
}
ac := &acfakes.FakeRuleService{}
h, err := configureHistorianBackend(context.Background(), cfg, nil, nil, nil, met, logger, tracer, ac, nil, nil, nil, nil, nil)
require.NotNil(t, h)
require.NoError(t, err)
exp := bytes.NewBufferString(`
# HELP grafana_alerting_state_history_info Information about the state history store.
# TYPE grafana_alerting_state_history_info gauge
grafana_alerting_state_history_info{backend="noop"} 0
`)
err = testutil.GatherAndCompare(reg, exp, "grafana_alerting_state_history_info")
require.NoError(t, err)
})
}
func TestConfigureNotificationHistorian(t *testing.T) {
t.Run("do not fail initialization if pinging Loki fails", func(t *testing.T) {
reg := prometheus.NewRegistry()
met := metrics.NewNotificationHistorianMetrics(reg)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
ft := featuremgmt.WithFeatures(featuremgmt.FlagAlertingNotificationHistory)
cfg := setting.UnifiedAlertingNotificationHistorySettings{
Enabled: true,
LokiSettings: setting.UnifiedAlertingLokiSettings{
// Should never resolve at the DNS level: https://www.rfc-editor.org/rfc/rfc6761#section-6.4
LokiRemoteURL: "http://gone.invalid",
},
}
h, err := configureNotificationHistorian(context.Background(), ft, cfg, met, logger, tracer)
require.NotNil(t, h)
require.NoError(t, err)
// Verify that the metric value is set to 1, indicating that notification history is enabled.
exp := bytes.NewBufferString(`
# HELP grafana_alerting_notification_history_info Information about the notification history store.
# TYPE grafana_alerting_notification_history_info gauge
grafana_alerting_notification_history_info 1
`)
err = testutil.GatherAndCompare(reg, exp, "grafana_alerting_notification_history_info")
require.NoError(t, err)
})
t.Run("emit special zero metric if notification history disabled", func(t *testing.T) {
testCases := []struct {
name string
ft featuremgmt.FeatureToggles
cfg setting.UnifiedAlertingNotificationHistorySettings
}{
{
"disabled via config",
featuremgmt.WithFeatures(featuremgmt.FlagAlertingNotificationHistory),
setting.UnifiedAlertingNotificationHistorySettings{Enabled: false},
},
{
"disabled via feature toggle",
featuremgmt.WithFeatures(),
setting.UnifiedAlertingNotificationHistorySettings{Enabled: true},
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
reg := prometheus.NewRegistry()
met := metrics.NewNotificationHistorianMetrics(reg)
logger := log.NewNopLogger()
tracer := tracing.InitializeTracerForTest()
h, err := configureNotificationHistorian(context.Background(), tc.ft, tc.cfg, met, logger, tracer)
require.Nil(t, h)
require.NoError(t, err)
exp := bytes.NewBufferString(`
# HELP grafana_alerting_notification_history_info Information about the notification history store.
# TYPE grafana_alerting_notification_history_info gauge
grafana_alerting_notification_history_info 0
`)
err = testutil.GatherAndCompare(reg, exp, "grafana_alerting_notification_history_info")
require.NoError(t, err)
})
}
})
}
type mockDB struct {
db.DB
}
func TestInitInstanceStore(t *testing.T) {
sqlStore := &mockDB{}
logger := log.New()
tests := []struct {
name string
ft featuremgmt.FeatureToggles
expectedInstanceStoreType interface{}
}{
{
name: "Compressed flag enabled, no periodic flag",
ft: featuremgmt.WithFeatures(
featuremgmt.FlagAlertingSaveStateCompressed,
),
expectedInstanceStoreType: store.ProtoInstanceDBStore{},
},
{
name: "Compressed flag enabled with periodic flag",
ft: featuremgmt.WithFeatures(
featuremgmt.FlagAlertingSaveStateCompressed,
featuremgmt.FlagAlertingSaveStatePeriodic,
),
expectedInstanceStoreType: store.ProtoInstanceDBStore{},
},
{
name: "Compressed flag disabled",
ft: featuremgmt.WithFeatures(),
expectedInstanceStoreType: store.InstanceDBStore{},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
instanceStore, instanceReader := initInstanceStore(sqlStore, logger, tt.ft)
assert.IsType(t, tt.expectedInstanceStoreType, instanceStore)
assert.IsType(t, &state.MultiInstanceReader{}, instanceReader)
assert.IsType(t, store.ProtoInstanceDBStore{}, instanceReader.(*state.MultiInstanceReader).ProtoDBReader)
assert.IsType(t, store.InstanceDBStore{}, instanceReader.(*state.MultiInstanceReader).DBReader)
})
}
}
func TestInitStatePersister(t *testing.T) {
ua := setting.UnifiedAlertingSettings{
StatePeriodicSaveInterval: 1 * time.Minute,
}
cfg := state.ManagerCfg{
StatePeriodicSaveInterval: 1 * time.Minute,
}
tests := []struct {
name string
ft featuremgmt.FeatureToggles
expectedStatePersisterType state.StatePersister
}{
{
name: "Compressed flag enabled",
ft: featuremgmt.WithFeatures(
featuremgmt.FlagAlertingSaveStateCompressed,
),
expectedStatePersisterType: &state.SyncRuleStatePersister{},
},
{
name: "Periodic flag enabled",
ft: featuremgmt.WithFeatures(
featuremgmt.FlagAlertingSaveStatePeriodic,
),
expectedStatePersisterType: &state.AsyncStatePersister{},
},
{
name: "No flags enabled",
ft: featuremgmt.WithFeatures(),
expectedStatePersisterType: &state.SyncStatePersister{},
},
{
name: "Both flags enabled - compressed takes precedence",
ft: featuremgmt.WithFeatures(
featuremgmt.FlagAlertingSaveStateCompressed,
featuremgmt.FlagAlertingSaveStatePeriodic,
),
expectedStatePersisterType: &state.SyncRuleStatePersister{},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
statePersister := initStatePersister(ua, cfg, tt.ft)
assert.IsType(t, tt.expectedStatePersisterType, statePersister)
})
}
}