Loki: Set Query limits context header (#114112)

* feat(lokiQueryLimitsContext): send full query range & expr on initial split requests

packages/grafana-data/src/types/featureToggles.gen.ts

@@ -596,7 +596,7 @@ export interface FeatureToggles {
   */
   alertingPrometheusRulesPrimary?: boolean;
   /**
-  * Used in Logs Drilldown to split queries into multiple queries based on the number of shards
+  * Deprecated. Replace with lokiShardSplitting. Used in Logs Drilldown to split queries into multiple queries based on the number of shards
   */
   exploreLogsShardSplitting?: boolean;
   /**
@@ -1178,6 +1178,10 @@ export interface FeatureToggles {
   */
   ttlPluginInstanceManager?: boolean;
   /**
+  * Send X-Loki-Query-Limits-Context header to Loki on first split request
+  */
+  lokiQueryLimitsContext?: boolean;
+  /**
   * Enables the new version of rudderstack
   * @default false
   */

packages/grafana-schema/src/raw/composable/loki/dataquery/x/LokiDataQuery_types.gen.ts

@@ -50,6 +50,14 @@ export interface LokiDataQuery extends common.DataQuery {
    * Used to override the name of the series.
    */
   legendFormat?: string;
+  /**
+   * The full query plan for split/shard queries. Encoded and sent to Loki via `X-Loki-Query-Limits-Context` header. Requires "lokiQueryLimitsContext" feature flag
+   */
+  limitsContext?: {
+    expr: string;
+    from: number;
+    to: number;
+  };
   /**
    * Used to limit the number of log rows returned.
    */