SERVER-32983 persist a version field in new config.databases entries in fcv>=4.0

1 files changed, 79 insertions, 0 deletions

diff --git a/jstests/sharding/create_database.js b/jstests/sharding/create_database.js
new file mode 100644
index 00000000000..4f31141f830
--- /dev/null
+++ b/jstests/sharding/create_database.js
@@ -0,0 +1,79 @@
+/**
+ * Tests that creating a database causes it to be written to the sharding catalog with a
+ * databaseVersion if FCV > 3.6, but not if FCV <= 3.6.
+ */
+(function() {
+    'use strict';
+
+    function createDatabase(st, dbName) {
+        // A database is implicitly created when a collection inside it is created.
+        assert.commandWorked(st.s.getDB(dbName).runCommand({create: collName}));
+    }
+
+    function cleanUp(st, dbName) {
+        assert.commandWorked(st.s.getDB(dbName).runCommand({dropDatabase: 1}));
+    }
+
+    function assertHasDbVersion(dbEntry) {
+        assert.neq(null, dbEntry);
+        assert.neq(null, dbEntry.version);
+        assert.neq(null, dbEntry.version.uuid);
+        assert.eq(1, dbEntry.version.lastMod);
+    }
+
+    function assertDoesntHaveDbVersion(dbEntry) {
+        assert.neq(null, dbEntry);
+        assert.eq(null, dbEntry.version);
+    }
+
+    const dbName = "db1";
+    const collName = "foo";
+
+    var st = new ShardingTest({shards: 1});
+
+    let dbEntry;
+
+    //
+    // FCV 4.0
+    //
+
+    assert.commandWorked(st.s.adminCommand({setFeatureCompatibilityVersion: "4.0"}));
+
+    // A new database is given a databaseVersion.
+    createDatabase(st, dbName);
+    let dbEntry1 = st.s.getDB("config").getCollection("databases").findOne({_id: dbName});
+    assertHasDbVersion(dbEntry1);
+    cleanUp(st, dbName);
+
+    // A new incarnation of a database that was previously dropped is given a fresh databaseVersion.
+    createDatabase(st, dbName);
+    let dbEntry2 = st.s.getDB("config").getCollection("databases").findOne({_id: dbName});
+    assertHasDbVersion(dbEntry2);
+    assert.neq(dbEntry1.version.uuid, dbEntry2.version.uuid);
+    cleanUp(st, dbName);
+
+    //
+    // FCV 3.6
+    //
+
+    assert.commandWorked(st.s.adminCommand({setFeatureCompatibilityVersion: "3.6"}));
+
+    // A new database is not given a databaseVersion.
+    createDatabase(st, dbName);
+    dbEntry = st.s.getDB("config").getCollection("databases").findOne({_id: dbName});
+    assertDoesntHaveDbVersion(dbEntry);
+    cleanUp(st, dbName);
+
+    //
+    // FCV 3.4 (This section can be deleted once FCV 3.4 is removed).
+    //
+
+    assert.commandWorked(st.s.adminCommand({setFeatureCompatibilityVersion: "3.4"}));
+
+    // A new database is not given a databaseVersion.
+    createDatabase(st, dbName);
+    dbEntry = st.s.getDB("config").getCollection("databases").findOne({_id: dbName});
+    assertDoesntHaveDbVersion(dbEntry);
+    cleanUp(st, dbName);
+
+})();