SERVER-83220 Introduce MultiCollectionRouter to correctly handle seco…

…ndary collection shard versions for SBE $lookup pushdown

Co-authored-by: Jordi Serra Torrens <jordi.serra-torrens@mongodb.com>
GitOrigin-RevId: a63db2a047e3b654820ac085a1207488b6418cd2

buildscripts/resmokeconfig/suites/aggregation_unsplittable_collections_on_random_shard_passthrough.yml

@@ -12,15 +12,21 @@ selector:
   - jstests/aggregation/use_query_projection.js
   - jstests/aggregation/use_query_sort.js
 
-  # TODO: SERVER-83220 (Failing due to incorrect pushdown of $lookup for non-collocated collections).
-  # Reenable:
-  - jstests/aggregation/sources/facet/inner_lookup.js
+  # These tests are written such that, after we check the engine being used and the colocation of
+  # the involved collections, we drop and recreate our collections for each test case. Given that
+  # this suite creates unsplittable collections on random shards and we cannot reliably check the
+  # colocation of collections in these tests, this means that these tests are incompatible with
+  # this suite as written.
+  # TODO SERVER-83351: Rewrite these tests to be compatible with this suite.
   - jstests/aggregation/sources/lookup/lookup_equijoin_semantics_inlj.js
   - jstests/aggregation/sources/lookup/lookup_equijoin_semantics_nlj.js
   - jstests/aggregation/sources/lookup/lookup_equijoin_semantics_hj.js
+
+  # TODO SERVER-85965: These tests currently fail because we do not track the collation of
+  # unsplittable collections in the sharding catalog, and we do not lookup the collation from the
+  # primary shard. Re-enable these tests once we either track this information, or look it up.
   - jstests/aggregation/sources/lookup/lookup_collation.js
   - jstests/aggregation/sources/lookup/lookup_foreign_collation.js
-  - jstests/aggregation/dbref.js
 
   # TODO: SERVER-83351 (failing due to incorrect explain expectations). Reenable:
   - jstests/aggregation/explain_writing_aggs.js

jstests/core/views/views_validation.js

@@ -134,6 +134,19 @@ makeView("v0", "ok", [makeFacet("v1")], ErrorCodes.ViewDepthLimitExceeded);
 makeView("v0", "ok", [makeUnion("v1")], ErrorCodes.ViewDepthLimitExceeded);
 
 // Test that querying a view that descends more than 20 views will fail.
+
+// If this is a sharded cluster, we run the initial aggregate once. If this doesn't have the
+// necessary routing information to detect that the view is invalid, this will throw a StaleConfig
+// error instead. In doing so it will obtain the routing information for 10 of our views (one on
+// each attempt), which will allow the subsequent aggregates to discover that the view chain is 20
+// deep and fail as expected.
+// TODO SERVER-85941: This ticket aims to prevent needing an extra aggregate to get some of the
+// routing information.
+if (db.getMongo().isMongos()) {
+    assert.commandFailedWithCode(
+        viewsDb.runCommand({aggregate: "v10", pipeline: [makeUnion("v1")], cursor: {}}),
+        [ErrorCodes.ViewDepthLimitExceeded, ErrorCodes.StaleConfig]);
+}
 assert.commandFailedWithCode(
     viewsDb.runCommand({aggregate: "v10", pipeline: [makeUnion("v1")], cursor: {}}),
     ErrorCodes.ViewDepthLimitExceeded);

jstests/libs/shard_targeting_util.js

@@ -93,6 +93,10 @@ export class ShardTargetingTest {
             const split = explain.splitPipeline;
             assert(split.hasOwnProperty("mergerPart"), explain);
             const mergerPart = split.mergerPart;
+            assert(
+                expectedMergingStages,
+                "Should have specified merging stages for test case if 'expectedMergingShard' was specified" +
+                    tojson(explain));
             assert(expectedMergingStages, explain);
             this._assertExpectedStages(expectedMergingStages, mergerPart, explain);
         } else {
@@ -117,10 +121,11 @@ export class ShardTargetingTest {
                 this._assertExpectedStages(expectedShardStages, stages, explain);
             }
 
+            const stage = getAggPlanStage(shard, "EQ_LOOKUP", true /* useQueryPlannerSection */);
             if (assertSBELookupPushdown) {
-                const stage =
-                    getAggPlanStage(shard, "EQ_LOOKUP", true /* useQueryPlannerSection */);
                 assert.neq(stage, null, shard);
+            } else {
+                assert.eq(stage, null, shard);
             }
         }
     }