SERVER-47189 Do a reconfig on upgrade to FCV 4.4 to add a config term

2 files changed, 67 insertions, 1 deletions

diff --git a/jstests/multiVersion/add_config_term_on_replset_upgrade.js b/jstests/multiVersion/add_config_term_on_replset_upgrade.js
new file mode 100644
index 00000000000..6ea1cb4b498
--- /dev/null
+++ b/jstests/multiVersion/add_config_term_on_replset_upgrade.js
@@ -0,0 +1,66 @@
+/**
+ * Test the upgrade of a replica set from last-stable to latest version succeeds and adds the "term"
+ * field of the config document.
+ */
+
+(function() {
+'use strict';
+
+load('jstests/multiVersion/libs/multi_rs.js');
+load('jstests/libs/test_background_ops.js');
+
+const newVersion = "latest";
+const oldVersion = "last-stable";
+
+let nodes = {
+    n1: {binVersion: oldVersion},
+    n2: {binVersion: oldVersion},
+    n3: {binVersion: oldVersion}
+};
+let replicaSetName = 'add_config_term_on_replset_upgrade';
+let rst = new ReplSetTest({name: replicaSetName, nodes: nodes});
+let nodenames = rst.nodeList();
+rst.startSet();
+rst.initiate({
+    "_id": replicaSetName,
+    "members": [
+        {"_id": 0, "host": nodenames[0]},
+        {"_id": 1, "host": nodenames[1]},
+        {"_id": 2, "host": nodenames[2]}
+    ]
+});
+
+// Upgrade the set.
+jsTest.log("Upgrading replica set..");
+rst.upgradeSet({binVersion: newVersion});
+jsTest.log("Upgrade complete.");
+
+let config = rst.getPrimary().getDB("local").getCollection("system.replset").findOne();
+assert(!config.hasOwnProperty("term"));
+
+let configInOldVersion = rst.getReplSetConfigFromNode();
+
+jsTest.log("Upgrading FCV to 4.4");
+let primary = rst.getPrimary();
+assert.commandWorked(primary.adminCommand({setFeatureCompatibilityVersion: latestFCV}));
+
+// Check that the term field exists in the config document on all nodes. The term of the config
+// should match the node's current term.
+rst.nodes.forEach(function(node) {
+    reconnect(node);
+    jsTestLog("Checking the config term on node " + tojson(node.host) + " after binary upgrade.");
+    let config = node.getDB("local").getCollection("system.replset").findOne();
+    let currentTerm = node.adminCommand({replSetGetStatus: 1}).term;
+    // Config should have a term field that matches the node's current term.
+    assert(config.hasOwnProperty("term"), tojson(config));
+    assert.eq(config.term, currentTerm, tojson(config));
+    // The configs can only differ in config versions and terms. Versions differ because of the
+    // force reconfig on upgrade.
+    configInOldVersion.term = config.term;
+    assert.eq(config.version, configInOldVersion.version + 1);
+    config.version = configInOldVersion.version;
+    assert.docEq(configInOldVersion, config);
+});
+
+rst.stopSet();
+})();
diff --git a/jstests/multiVersion/genericSetFCVUsage/set_feature_compatibility_version.js b/jstests/multiVersion/genericSetFCVUsage/set_feature_compatibility_version.js
index 02e6fbb9d40..9f820eb407b 100644
--- a/jstests/multiVersion/genericSetFCVUsage/set_feature_compatibility_version.js
+++ b/jstests/multiVersion/genericSetFCVUsage/set_feature_compatibility_version.js
@@ -221,7 +221,7 @@ secondaryAdminDB = secondary.getDB("admin");
 // Rig the election so that the first node running latest version remains the primary after the
 // 'lastStable' secondary is added to the replica set.
 replSetConfig = rst.getReplSetConfig();
-replSetConfig.version = 4;
+replSetConfig.version = rst.getReplSetConfigFromNode().version + 1;
 replSetConfig.members[2].priority = 0;
 reconfig(rst, replSetConfig);