Distributing sum queries

CHANGELOG.md

@@ -3,7 +3,7 @@
 ## master / unreleased
 
 * [FEATURE] Fan out parallelizable queries to backend queriers concurrently. #1878
-  * `-querier.sum-shards` (bool)
+  * `querier.parallelise-shardable-queries` (bool)
   * Requires a shard-compatible schema (v10+)
   * This causes the number of traces to increase accordingly.
   * The query-frontend now requires a schema config to determine how/when to shard queries, either from a file or from flags (i.e. by the `config-yaml` CLI flag). This is the same schema config the queriers consume. The schema is only required to use this option.

docs/configuration/arguments.md

@@ -68,7 +68,7 @@ The ingester query API was improved over time, but defaults to the old behaviour
 
 ## Query Frontend
 
-- `-querier.sum-shards`
+- `-querier.parallelise-shardable-queries`
 
    If set to true, will cause the query frontend to mutate incoming queries when possible by turning `sum` operations into sharded `sum` operations. This requires a shard-compatible schema (v10+). An abridged example:
    `sum by (foo) (rate(bar{baz=”blip”}[1m]))` ->

docs/configuration/config-file-reference.md

@@ -642,9 +642,9 @@ results_cache:
 # CLI flag: -querier.max-retries-per-request
 [max_retries: <int> | default = 5]
 
-# Parse the ast and parallelize sums by shard.
-# CLI flag: -querier.sum-shards
-[sum_shards: <boolean> | default = false]
+# Perform query parallelisations based on storage sharding configuration and query ASTs.
+# CLI flag: -querier.parallelise-shardable-queries
+[parallelise_shardable_queries: <boolean> | default = false]
 ```
 
 ## `ruler_config`

pkg/querier/queryrange/roundtrip.go

@@ -53,7 +53,7 @@ type Config struct {
 	ResultsCacheConfig     `yaml:"results_cache"`
 	CacheResults           bool `yaml:"cache_results"`
 	MaxRetries             int  `yaml:"max_retries"`
-	SumShards              bool `yaml:"sum_shards"`
+	ShardedQueries         bool `yaml:"parallelise_shardable_queries"`
 }
 
 // RegisterFlags adds the flags required to config this to the given FlagSet.
@@ -63,7 +63,7 @@ func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 	f.DurationVar(&cfg.SplitQueriesByInterval, "querier.split-queries-by-interval", 0, "Split queries by an interval and execute in parallel, 0 disables it. You should use an a multiple of 24 hours (same as the storage bucketing scheme), to avoid queriers downloading and processing the same chunks. This also determines how cache keys are chosen when result caching is enabled")
 	f.BoolVar(&cfg.AlignQueriesWithStep, "querier.align-querier-with-step", false, "Mutate incoming queries to align their start and end with their step.")
 	f.BoolVar(&cfg.CacheResults, "querier.cache-results", false, "Cache query results.")
-	f.BoolVar(&cfg.SumShards, "querier.sum-shards", false, "Parse the ast and parallelize sums by shard.")
+	f.BoolVar(&cfg.ShardedQueries, "querier.parallelise-shardable-queries", false, "Perform query parallelisations based on storage sharding configuration and query ASTs.")
 	cfg.ResultsCacheConfig.RegisterFlags(f)
 }
 
@@ -146,7 +146,7 @@ func NewTripperware(
 		queryRangeMiddleware = append(queryRangeMiddleware, InstrumentMiddleware("results_cache"), queryCacheMiddleware)
 	}
 
-	if cfg.SumShards {
+	if cfg.ShardedQueries {
 		if minShardingLookback == 0 {
 			return nil, nil, errInvalidMinShardingLookback
 		}

pkg/querier/queryrange/roundtrip_test.go

@@ -108,7 +108,7 @@ func (s singleHostRoundTripper) RoundTrip(r *http.Request) (*http.Response, erro
 
 func Test_ShardingConfigError(t *testing.T) {
 	_, _, err := NewTripperware(
-		Config{SumShards: true},
+		Config{ShardedQueries: true},
 		log.NewNopLogger(),
 		nil,
 		nil,