SERVER-31275 Ensure causal consistency guarantees on secondaries during chunk migration commits, and fully invalidate metadata.

3 files changed, 33 insertions, 14 deletions

diff --git a/jstests/sharding/safe_secondary_reads_drop_recreate.js b/jstests/sharding/safe_secondary_reads_drop_recreate.js
index d5be9f69efd..4e43675e86f 100644
--- a/jstests/sharding/safe_secondary_reads_drop_recreate.js
+++ b/jstests/sharding/safe_secondary_reads_drop_recreate.js
@@ -562,13 +562,21 @@
             // Do any test-specific setup.
             test.setUp(staleMongos);
 
+            // Do dummy read from the stale mongos so it loads the routing table into memory once.
+            // Additionally, do a secondary read to ensure that the secondary has loaded the initial
+            // routing table -- the first read to the primary will refresh the mongos' shardVersion,
+            // which will then be used against the secondary to ensure the secondary is fresh.
+            assert.commandWorked(staleMongos.getDB(db).runCommand({find: coll}));
+            assert.commandWorked(freshMongos.getDB(db).runCommand({
+                find: coll,
+                $readPreference: {mode: 'secondary'},
+                readConcern: {'level': 'local'}
+            }));
+
             // Turn on system profiler on both secondaries.
             assert.commandWorked(st.rs0.getSecondary().getDB(db).setProfilingLevel(2));
             assert.commandWorked(st.rs1.getSecondary().getDB(db).setProfilingLevel(2));
 
-            // Do dummy read from the stale mongos so it loads the routing table into memory once.
-            assert.commandWorked(staleMongos.getDB(db).runCommand({find: coll}));
-
             scenarios[scenario](staleMongos, freshMongos, test, commandProfile);
 
             // Clean up the database by dropping it; this is the only way to drop the profiler
diff --git a/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js b/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js
index 6d0248e60b6..aa9ca818d8c 100644
--- a/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js
+++ b/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js
@@ -391,8 +391,13 @@
         assert.commandWorked(freshMongos.adminCommand({shardCollection: nss, key: {x: 1}}));
         assert.commandWorked(freshMongos.adminCommand({split: nss, middle: {x: 0}}));
 
-        // Do dummy read from the stale mongos so that it loads the routing table into memory once.
+        // Do dummy read from the stale mongos so it loads the routing table into memory once.
+        // Additionally, do a secondary read to ensure that the secondary has loaded the initial
+        // routing table -- the first read to the primary will refresh the mongos' shardVersion,
+        // which will then be used against the secondary to ensure the secondary is fresh.
         assert.commandWorked(staleMongos.getDB(db).runCommand({find: coll}));
+        assert.commandWorked(freshMongos.getDB(db).runCommand(
+            {find: coll, $readPreference: {mode: 'secondary'}, readConcern: {'level': 'local'}}));
 
         // Do any test-specific setup.
         test.setUp(staleMongos);
diff --git a/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js b/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js
index 7204a4b83c7..129197b42a8 100644
--- a/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js
+++ b/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js
@@ -332,13 +332,6 @@
     let freshMongos = st.s0;
     let staleMongos = st.s1;
 
-    assert.commandWorked(staleMongos.adminCommand({enableSharding: db}));
-    st.ensurePrimaryShard(db, st.shard0.shardName);
-
-    // Turn on system profiler on secondaries to collect data on all database operations.
-    assert.commandWorked(donorShardSecondary.getDB(db).setProfilingLevel(2));
-    assert.commandWorked(recipientShardSecondary.getDB(db).setProfilingLevel(2));
-
     let res = st.s.adminCommand({listCommands: 1});
     assert.commandWorked(res);
 
@@ -356,15 +349,26 @@
 
         jsTest.log("testing command " + tojson(test.command));
 
+        assert.commandWorked(staleMongos.adminCommand({enableSharding: db}));
+        st.ensurePrimaryShard(db, st.shard0.shardName);
         assert.commandWorked(staleMongos.adminCommand({shardCollection: nss, key: {x: 1}}));
         assert.commandWorked(staleMongos.adminCommand({split: nss, middle: {x: 0}}));
 
-        // Do dummy read from the stale mongos so that it loads the routing table into memory once.
+        // Do dummy read from the stale mongos so it loads the routing table into memory once.
+        // Additionally, do a secondary read to ensure that the secondary has loaded the initial
+        // routing table -- the first read to the primary will refresh the mongos' shardVersion,
+        // which will then be used against the secondary to ensure the secondary is fresh.
         assert.commandWorked(staleMongos.getDB(db).runCommand({find: coll}));
+        assert.commandWorked(freshMongos.getDB(db).runCommand(
+            {find: coll, $readPreference: {mode: 'secondary'}, readConcern: {'level': 'local'}}));
 
         // Do any test-specific setup.
         test.setUp(staleMongos);
 
+        // Turn on system profiler on secondaries to collect data on all database operations.
+        assert.commandWorked(donorShardSecondary.getDB(db).setProfilingLevel(2));
+        assert.commandWorked(recipientShardSecondary.getDB(db).setProfilingLevel(2));
+
         // Do a moveChunk from the fresh mongos to make the other mongos stale.
         // Use {w:2} (all) write concern so the metadata change gets persisted to the secondary
         // before stalely versioned commands are sent against the secondary.
@@ -450,8 +454,10 @@
             });
         }
 
-        // Clean up the collection by dropping it. This also drops all associated indexes.
-        assert.commandWorked(freshMongos.getDB(db).runCommand({drop: coll}));
+        // Clean up the database by dropping it; this is the only way to drop the profiler
+        // collection on secondaries. This also drops all associated indexes.
+        // Do this from staleMongos, so staleMongos purges the database entry from its cache.
+        assert.commandWorked(staleMongos.getDB(db).runCommand({dropDatabase: 1}));
     }
 
     st.stop();