From 38e71d62bc34b9db2c29669477cfcfed70927ffa Mon Sep 17 00:00:00 2001
From: Kaviraj <kavirajkanagaraj@gmail.com>
Date: Tue, 20 Feb 2024 08:38:07 +0100
Subject: [PATCH] Add cache hit log lines for instant metric query

Signed-off-by: Kaviraj <kavirajkanagaraj@gmail.com>
---
 cmd/loki/loki-local-with-memcached.yaml        | 11 +++++++++++
 pkg/logql/metrics.go                           | 17 ++++++++++++-----
 pkg/querier/queryrange/instant_metric_cache.go |  4 +++-
 pkg/querier/queryrange/split_by_range.go       |  2 +-
 4 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/cmd/loki/loki-local-with-memcached.yaml b/cmd/loki/loki-local-with-memcached.yaml
index d1b0ae1c2493c..a2f4336cdd484 100644
--- a/cmd/loki/loki-local-with-memcached.yaml
+++ b/cmd/loki/loki-local-with-memcached.yaml
@@ -22,6 +22,17 @@ query_range:
   cache_results: true
   cache_volume_results: true
   cache_series_results: true
+  cache_instant_metric_results: true
+  instant_metric_query_split_align: true
+  instant_metric_results_cache:
+    cache:
+      default_validity: 12h
+      memcached_client:
+        consistent_hash: true
+        addresses: "dns+localhost:11211"
+        max_idle_conns: 16
+        timeout: 500ms
+        update_interval: 1m
   series_results_cache:
     cache:
       default_validity: 12h
diff --git a/pkg/logql/metrics.go b/pkg/logql/metrics.go
index 40fbece82d87d..b55e9840a4758 100644
--- a/pkg/logql/metrics.go
+++ b/pkg/logql/metrics.go
@@ -94,7 +94,8 @@ func RecordRangeAndInstantQueryMetrics(
 ) {
 	var (
 		logger        = fixLogger(ctx, log)
-		rt            = string(GetRangeType(p))
+		rangeType     = GetRangeType(p)
+		rt            = string(rangeType)
 		latencyType   = latencyTypeFast
 		returnedLines = 0
 	)
@@ -103,6 +104,12 @@ func RecordRangeAndInstantQueryMetrics(
 		level.Warn(logger).Log("msg", "error parsing query type", "err", err)
 	}
 
+	resultCache := stats.Caches.Result
+
+	if queryType == QueryTypeMetric && rangeType == InstantType {
+		resultCache = stats.Caches.InstantMetricResult
+	}
+
 	// Tag throughput metric by latency type based on a threshold.
 	// Latency below the threshold is fast, above is slow.
 	if stats.Summary.ExecTime > slowQueryThresholdSecond {
@@ -162,10 +169,10 @@ func RecordRangeAndInstantQueryMetrics(
 		"cache_volume_results_req", stats.Caches.VolumeResult.EntriesRequested,
 		"cache_volume_results_hit", stats.Caches.VolumeResult.EntriesFound,
 		"cache_volume_results_download_time", stats.Caches.VolumeResult.CacheDownloadTime(),
-		"cache_result_req", stats.Caches.Result.EntriesRequested,
-		"cache_result_hit", stats.Caches.Result.EntriesFound,
-		"cache_result_download_time", stats.Caches.Result.CacheDownloadTime(),
-		"cache_result_query_length_served", stats.Caches.Result.CacheQueryLengthServed(),
+		"cache_result_req", resultCache.EntriesRequested,
+		"cache_result_hit", resultCache.EntriesFound,
+		"cache_result_download_time", resultCache.CacheDownloadTime(),
+		"cache_result_query_length_served", resultCache.CacheQueryLengthServed(),
 	}...)
 
 	logValues = append(logValues, tagsToKeyValues(queryTags)...)
diff --git a/pkg/querier/queryrange/instant_metric_cache.go b/pkg/querier/queryrange/instant_metric_cache.go
index cf4d4639b4c19..ef1083e6cd229 100644
--- a/pkg/querier/queryrange/instant_metric_cache.go
+++ b/pkg/querier/queryrange/instant_metric_cache.go
@@ -49,6 +49,8 @@ func (cfg *InstantMetricCacheConfig) Validate() error {
 	return cfg.ResultsCacheConfig.Validate()
 }
 
+type instantMetricExtractor struct{}
+
 func NewInstantMetricCacheMiddleware(
 	log log.Logger,
 	limits Limits,
@@ -67,7 +69,7 @@ func NewInstantMetricCacheMiddleware(
 		InstantMetricSplitter{limits, transformer},
 		limits,
 		merger,
-		queryrangebase.PrometheusResponseExtractor{},
+		PrometheusExtractor{},
 		cacheGenNumberLoader,
 		func(ctx context.Context, r queryrangebase.Request) bool {
 			if shouldCache != nil && !shouldCache(ctx, r) {
diff --git a/pkg/querier/queryrange/split_by_range.go b/pkg/querier/queryrange/split_by_range.go
index 3e570350303ef..16076cd948596 100644
--- a/pkg/querier/queryrange/split_by_range.go
+++ b/pkg/querier/queryrange/split_by_range.go
@@ -62,7 +62,7 @@ func (s *splitByRange) Do(ctx context.Context, request queryrangebase.Request) (
 		return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
 	}
 
-	interval := validation.SmallestPositiveNonZeroDurationPerTenant(tenants, s.limits.QuerySplitDuration)
+	interval := validation.SmallestPositiveNonZeroDurationPerTenant(tenants, s.limits.InstantMetricQuerySplitDuration)
 	// if no interval configured, continue to the next middleware
 	if interval == 0 {
 		return s.next.Do(ctx, request)