Feature/per tenant splitby (#1565)

* split by overrides by tenant

* tenant aware metric query splitting

* consistent split_queries_by_interval naming

* updates readme

* fixes rebase conflict

* refactor to support limit based splitby intervals in all locations

* simplifies limits cachesplitter

* fixes comment

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * [1572](https://github.com/grafana/loki/pull/1572) **owen-d**: Introduces the `querier.query-ingesters-within` flag and associated yaml config. When enabled, queries for a time range that do not overlap this lookback interval will not be sent to the ingesters.
 * [1558](https://github.com/grafana/loki/pull/1558) **owen-d**: Introduces `ingester.max-chunk-age` which specifies the maximum chunk age before it's cut.
+* [1565](https://github.com/grafana/loki/pull/1565) **owen-d**: The query frontend's `split_queries_by_interval` can now be specified as an override
 
 ## 1.3.0 (2020-01-16)
 

pkg/querier/queryrange/limits.go

@@ -0,0 +1,56 @@
+package queryrange
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/cortexproject/cortex/pkg/querier/queryrange"
+)
+
+// Limits extends the cortex limits interface with support for per tenant splitby parameters
+type Limits interface {
+	queryrange.Limits
+	QuerySplitDuration(string) time.Duration
+}
+
+type limits struct {
+	Limits
+	splitDuration time.Duration
+}
+
+func (l limits) QuerySplitDuration(user string) time.Duration {
+	dur := l.Limits.QuerySplitDuration(user)
+	if dur == 0 {
+		return l.splitDuration
+	}
+	return dur
+}
+
+// WithDefaults will construct a Limits with a default value for QuerySplitDuration when no overrides are present.
+func WithDefaultLimits(l Limits, conf queryrange.Config) Limits {
+	res := limits{
+		Limits: l,
+	}
+
+	if conf.SplitQueriesByDay {
+		res.splitDuration = 24 * time.Hour
+	}
+
+	if conf.SplitQueriesByInterval != 0 {
+		res.splitDuration = conf.SplitQueriesByInterval
+	}
+
+	return res
+}
+
+// cacheKeyLimits intersects Limits and CacheSplitter
+type cacheKeyLimits struct {
+	Limits
+}
+
+// GenerateCacheKey will panic if it encounters a 0 split duration. We ensure against this by requiring
+// a nonzero split interval when caching is enabled
+func (l cacheKeyLimits) GenerateCacheKey(userID string, r queryrange.Request) string {
+	currentInterval := r.GetStart() / int64(l.QuerySplitDuration(userID)/time.Millisecond)
+	return fmt.Sprintf("%s:%s:%d:%d", userID, r.GetQuery(), r.GetStep(), currentInterval)
+}

pkg/querier/queryrange/limits_test.go

@@ -0,0 +1,34 @@
+package queryrange
+
+import (
+	"testing"
+	"time"
+
+	"github.com/cortexproject/cortex/pkg/querier/queryrange"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWithDefaultLimits(t *testing.T) {
+	l := fakeLimits{
+		splits: map[string]time.Duration{"a": time.Minute},
+	}
+
+	require.Equal(t, l.QuerySplitDuration("a"), time.Minute)
+	require.Equal(t, l.QuerySplitDuration("b"), time.Duration(0))
+
+	wrapped := WithDefaultLimits(l, queryrange.Config{
+		SplitQueriesByDay: true,
+	})
+
+	require.Equal(t, wrapped.QuerySplitDuration("a"), time.Minute)
+	require.Equal(t, wrapped.QuerySplitDuration("b"), 24*time.Hour)
+
+	wrapped = WithDefaultLimits(l, queryrange.Config{
+		SplitQueriesByDay:      true, // should be overridden by SplitQueriesByInterval
+		SplitQueriesByInterval: time.Hour,
+	})
+
+	require.Equal(t, wrapped.QuerySplitDuration("a"), time.Minute)
+	require.Equal(t, wrapped.QuerySplitDuration("b"), time.Hour)
+
+}

pkg/querier/queryrange/roundtrip.go

@@ -5,9 +5,11 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/cortexproject/cortex/pkg/chunk/cache"
 	"github.com/cortexproject/cortex/pkg/querier/frontend"
 	"github.com/cortexproject/cortex/pkg/querier/queryrange"
 	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
 	"github.com/grafana/loki/pkg/logql"
 	"github.com/prometheus/prometheus/pkg/labels"
 )
@@ -28,8 +30,13 @@ type Stopper interface {
 }
 
 // NewTripperware returns a Tripperware configured with middlewares to align, split and cache requests.
-func NewTripperware(cfg Config, log log.Logger, limits queryrange.Limits) (frontend.Tripperware, Stopper, error) {
-	metricsTripperware, cache, err := queryrange.NewTripperware(cfg.Config, log, limits, lokiCodec, queryrange.PrometheusResponseExtractor)
+func NewTripperware(cfg Config, log log.Logger, limits Limits) (frontend.Tripperware, Stopper, error) {
+	// Ensure that QuerySplitDuration uses configuration defaults.
+	// This avoids divide by zero errors when determining cache keys where user specific overrides don't exist.
+	limits = WithDefaultLimits(limits, cfg.Config)
+
+	metricsTripperware, cache, err := NewMetricTripperware(cfg, log, limits, lokiCodec, queryrange.PrometheusResponseExtractor)
+
 	if err != nil {
 		return nil, nil, err
 	}
@@ -78,12 +85,12 @@ func NewTripperware(cfg Config, log log.Logger, limits queryrange.Limits) (front
 func NewLogFilterTripperware(
 	cfg Config,
 	log log.Logger,
-	limits queryrange.Limits,
+	limits Limits,
 	codec queryrange.Codec,
 ) (frontend.Tripperware, error) {
 	queryRangeMiddleware := []queryrange.Middleware{queryrange.LimitsMiddleware(limits)}
 	if cfg.SplitQueriesByInterval != 0 {
-		queryRangeMiddleware = append(queryRangeMiddleware, queryrange.InstrumentMiddleware("split_by_interval"), SplitByIntervalMiddleware(cfg.SplitQueriesByInterval, limits, codec))
+		queryRangeMiddleware = append(queryRangeMiddleware, queryrange.InstrumentMiddleware("split_by_interval"), SplitByIntervalMiddleware(limits, codec))
 	}
 	if cfg.MaxRetries > 0 {
 		queryRangeMiddleware = append(queryRangeMiddleware, queryrange.InstrumentMiddleware("retry"), queryrange.NewRetryMiddleware(log, cfg.MaxRetries))
@@ -95,3 +102,76 @@ func NewLogFilterTripperware(
 		return next
 	}), nil
 }
+
+// NewMetricTripperware creates a new frontend tripperware responsible for handling metric queries
+func NewMetricTripperware(
+	cfg Config,
+	log log.Logger,
+	limits Limits,
+	codec queryrange.Codec,
+	extractor queryrange.Extractor,
+) (frontend.Tripperware, Stopper, error) {
+
+	queryRangeMiddleware := []queryrange.Middleware{queryrange.LimitsMiddleware(limits)}
+	if cfg.AlignQueriesWithStep {
+		queryRangeMiddleware = append(
+			queryRangeMiddleware,
+			queryrange.InstrumentMiddleware("step_align"),
+			queryrange.StepAlignMiddleware,
+		)
+	}
+
+	// SplitQueriesByDay is deprecated use SplitQueriesByInterval.
+	if cfg.SplitQueriesByDay {
+		level.Warn(log).Log("msg", "flag querier.split-queries-by-day (or config split_queries_by_day) is deprecated, use querier.split-queries-by-interval instead.")
+	}
+
+	queryRangeMiddleware = append(
+		queryRangeMiddleware,
+		queryrange.InstrumentMiddleware("split_by_interval"),
+		SplitByIntervalMiddleware(limits, codec),
+	)
+
+	var c cache.Cache
+	if cfg.CacheResults {
+		queryCacheMiddleware, cache, err := queryrange.NewResultsCacheMiddleware(
+			log,
+			cfg.ResultsCacheConfig,
+			cacheKeyLimits{limits},
+			limits,
+			codec,
+			extractor,
+		)
+		if err != nil {
+			return nil, nil, err
+		}
+		c = cache
+		queryRangeMiddleware = append(
+			queryRangeMiddleware,
+			queryrange.InstrumentMiddleware("results_cache"),
+			queryCacheMiddleware,
+		)
+	}
+
+	if cfg.MaxRetries > 0 {
+		queryRangeMiddleware = append(
+			queryRangeMiddleware,
+			queryrange.InstrumentMiddleware("retry"),
+			queryrange.NewRetryMiddleware(log, cfg.MaxRetries),
+		)
+	}
+
+	return frontend.Tripperware(func(next http.RoundTripper) http.RoundTripper {
+		// Finally, if the user selected any query range middleware, stitch it in.
+		if len(queryRangeMiddleware) > 0 {
+			rt := queryrange.NewRoundTripper(next, codec, queryRangeMiddleware...)
+			return frontend.RoundTripFunc(func(r *http.Request) (*http.Response, error) {
+				if !strings.HasSuffix(r.URL.Path, "/query_range") {
+					return next.RoundTrip(r)
+				}
+				return rt.RoundTrip(r)
+			})
+		}
+		return next
+	}), c, nil
+}

pkg/querier/queryrange/roundtrip_test.go

@@ -287,6 +287,14 @@ func TestRegexpParamsSupport(t *testing.T) {
 
 type fakeLimits struct {
 	maxQueryParallelism int
+	splits              map[string]time.Duration
+}
+
+func (f fakeLimits) QuerySplitDuration(key string) time.Duration {
+	if f.splits == nil {
+		return 0
+	}
+	return f.splits[key]
 }
 
 func (fakeLimits) MaxQueryLength(string) time.Duration {

pkg/querier/queryrange/split_by_interval.go

@@ -12,13 +12,12 @@ import (
 )
 
 // SplitByIntervalMiddleware creates a new Middleware that splits log requests by a given interval.
-func SplitByIntervalMiddleware(interval time.Duration, limits queryrange.Limits, merger queryrange.Merger) queryrange.Middleware {
+func SplitByIntervalMiddleware(limits Limits, merger queryrange.Merger) queryrange.Middleware {
 	return queryrange.MiddlewareFunc(func(next queryrange.Handler) queryrange.Handler {
 		return &splitByInterval{
-			next:     next,
-			limits:   limits,
-			merger:   merger,
-			interval: interval,
+			next:   next,
+			limits: limits,
+			merger: merger,
 		}
 	})
 }
@@ -34,10 +33,9 @@ type packedResp struct {
 }
 
 type splitByInterval struct {
-	next     queryrange.Handler
-	limits   queryrange.Limits
-	merger   queryrange.Merger
-	interval time.Duration
+	next   queryrange.Handler
+	limits Limits
+	merger queryrange.Merger
 }
 
 func (h *splitByInterval) Feed(ctx context.Context, input []*lokiResult) chan *lokiResult {
@@ -69,6 +67,12 @@ func (h *splitByInterval) Process(
 
 	ch := h.Feed(ctx, input)
 
+	// queries with 0 limits should not be exited early
+	var unlimited bool
+	if threshold == 0 {
+		unlimited = true
+	}
+
 	// don't spawn unnecessary goroutines
 	var p int = parallelism
 	if len(input) < parallelism {
@@ -91,10 +95,15 @@ func (h *splitByInterval) Process(
 			responses = append(responses, data.resp)
 
 			// see if we can exit early if a limit has been reached
-			threshold -= data.resp.(*LokiResponse).Count()
-			if threshold <= 0 {
-				return responses, nil
+			if casted, ok := data.resp.(*LokiResponse); !unlimited && ok {
+				threshold -= casted.Count()
+
+				if threshold <= 0 {
+					return responses, nil
+				}
+
 			}
+
 		}
 
 	}
@@ -129,7 +138,13 @@ func (h *splitByInterval) Do(ctx context.Context, r queryrange.Request) (queryra
 		return nil, err
 	}
 
-	intervals := splitByTime(lokiRequest, h.interval)
+	interval := h.limits.QuerySplitDuration(userid)
+	// skip split by if unset
+	if interval == 0 {
+		return h.next.Do(ctx, r)
+	}
+
+	intervals := splitByTime(lokiRequest, interval)
 
 	if sp := opentracing.SpanFromContext(ctx); sp != nil {
 		sp.LogFields(otlog.Int("n_intervals", len(intervals)))