SERVER-26156 Add migration tests for collections with V2 indexes

1 files changed, 72 insertions, 0 deletions

diff --git a/jstests/multiVersion/index_v2_migration.js b/jstests/multiVersion/index_v2_migration.js
new file mode 100644
index 00000000000..ea0fd1b9390
--- /dev/null
+++ b/jstests/multiVersion/index_v2_migration.js
@@ -0,0 +1,72 @@
+// Test chunk migration from collections with V2 indexes.
+
+(function() {
+    'use strict';
+    load('jstests/libs/get_index_helpers.js');
+    load('jstests/libs/override_methods/multiversion_override_balancer_control.js');
+    const latest = 'latest';
+    const downgrade = '3.2';
+    var testDb = 'test';
+
+    //
+    // Ensure that we can successfully migrate a chunk of a collection with a V2 index between 3.4
+    // shards with featureCompatibilityVersion 3.2.
+    //
+
+    // Create a 3.4 sharded cluster.
+    var st = new ShardingTest({mongos: 1, shards: 2});
+    var shard0 = st.shard0.shardName;
+    var shard1 = st.shard1.shardName;
+
+    // Create a sharded collection with a V2 index.
+    assert.commandWorked(st.s.adminCommand({enableSharding: testDb}));
+    st.ensurePrimaryShard(testDb, shard1);
+    assert.commandWorked(st.s.getDB(testDb).createCollection('foo'));
+    assert.commandWorked(st.s.getDB(testDb).foo.createIndex({a: 1}, {v: 2}));
+    assert.commandWorked(st.s.adminCommand({shardCollection: testDb + '.foo', key: {a: 1}}));
+    var indexSpec = GetIndexHelpers.findByName(st.shard1.getDB(testDb).foo.getIndexes(), 'a_1');
+    assert.neq(null, indexSpec);
+    assert.eq(2, indexSpec.v, tojson(indexSpec));
+
+    // Successfully migrate a chunk from the collection with a V2 index between shards.
+    assert.commandWorked(st.s.adminCommand({setFeatureCompatibilityVersion: '3.2'}));
+    assert.commandWorked(st.s.adminCommand({moveChunk: testDb + '.foo', find: {a: 1}, to: shard0}));
+
+    // Make sure the index is V2 on the destination shard.
+    indexSpec = GetIndexHelpers.findByName(st.shard0.getDB(testDb).foo.getIndexes(), 'a_1');
+    assert.neq(null, indexSpec);
+    assert.eq(2, indexSpec.v, tojson(indexSpec));
+    st.stop();
+
+    //
+    // Ensure that we fail to migrate a chunk of a collection with a V2 index from a 3.4 mongod
+    // shard to a 3.2 mongod shard.
+    //
+
+    // Create a 3.4 mongod with a collection that has a V2 index.
+    var chunkSource = MongoRunner.runMongod({shardsvr: '', binVersion: latest});
+    assert.neq(null, chunkSource);
+    assert.commandWorked(chunkSource.adminCommand({setFeatureCompatibilityVersion: '3.4'}));
+    assert.commandWorked(chunkSource.getDB(testDb).createCollection('foo'));
+    assert.commandWorked(chunkSource.getDB(testDb).foo.createIndex({a: 1}, {v: 2}));
+
+    // Set mongod's featureCompatibilityVersion to 3.2 so that we can add it to a 3.2 cluster.
+    assert.commandWorked(chunkSource.adminCommand({setFeatureCompatibilityVersion: '3.2'}));
+
+    // Create a 3.2 sharded cluster with one shard and add the 3.4 mongod to it.
+    st = new ShardingTest({
+        shards: 1,
+        other: {mongosOptions: {binVersion: downgrade}, shardOptions: {binVersion: downgrade}}
+    });
+    assert.commandWorked(st.s.adminCommand({addShard: chunkSource.name}));
+    assert.commandWorked(st.s.adminCommand({enableSharding: testDb}));
+    st.ensurePrimaryShard(testDb, shard1);
+    assert.commandWorked(st.s.adminCommand({shardCollection: testDb + '.foo', key: {a: 1}}));
+
+    // Fail to migrate a chunk of the collection with a V2 index to the 3.2 shard.
+    assert.commandFailedWithCode(
+        st.s.adminCommand({moveChunk: testDb + '.foo', find: {a: 1}, to: shard0}),
+        ErrorCodes.OperationFailed,
+        'Move chunk unexpectedly succeeded. Expected to fail since 3.2 cannot build V2 indexes.');
+    st.stop();
+})();