SERVER-50585: Create set_fcv_downgrade_on_disk_changes.js to include all test cases for downgradeOnDiskChanges behavior

Author: ldennis

jstests/multiVersion/genericSetFCVUsage/set_fcv_downgrade_on_disk_changes.js

@@ -0,0 +1,247 @@
+/**
+ * Unified test that makes sure calling setFeatureCompatibilityVersion with
+ * {downgradeOnDiskChanges: true} is able to successfully downgrade all expected on-disk changes in
+ * one invocation.
+ */
+(function() {
+"use strict";
+
+load('jstests/multiVersion/libs/multi_rs.js');
+load('jstests/multiVersion/libs/multi_cluster.js');
+
+let dbpath = MongoRunner.dataPath + jsTestName();
+resetDbpath(dbpath);
+
+const latest = "latest";
+const lastContinuous = "last-continuous";
+
+/**
+ * Each new feature that adds downgrade logic to the setFeatureCompatibilityVersion command with
+ * {downgradeOnDiskChanges: true} should add their test cases to this test file. Each test case
+ * should follow this 'dummyTest' template and implement the following three test functions:
+ * this.onDiskChangesBeforeDowngrade: This function will be called before the FCV downgrade to
+ * introduce durable on-disk changes that will be downgraded as part the FCV downgrade.
+ * this.validateAfterFCVDowngrade: This function will be called after the FCV downgrade to validate
+ * the downgrade of the incompatible on-disk changes introduced in onDiskChangesBeforeDowngrade.
+ * this.validateAfterBinaryDowngrade: This function will be called after the binary downgrade to
+ * 'last-continuous' binaries to validate the downgrade of the incompatible on-disk changes
+ * introduced in onDiskChangesBeforeDowngrade.
+ *
+ * Each new test should also be added to the downgradeOnDiskChangesTests list below.
+ */
+function dummyTest() {
+    const documents = [{_id: "dummy"}];
+    this.onDiskChangesBeforeDowngrade = function(conn) {
+        jsTestLog("Running onDiskChangesBeforeDowngrade of dummyTest");
+        let testDB = conn.getDB("test");
+        assert.commandWorked(testDB.runCommand({insert: "dummy", documents: documents}));
+    };
+
+    this.validateAfterFCVDowngrade = function(conn) {
+        jsTestLog("Running validateAfterFCVDowngrade of dummyTest");
+        let testDB = conn.getDB("test");
+        let res = testDB.dummy.find({});
+        assert.sameMembers(res.toArray(), documents, () => tojson(res));
+    };
+
+    this.validateAfterBinaryDowngrade = function(conn) {
+        jsTestLog("Running validateAfterBinaryDowngrade of dummyTest");
+        this.validateAfterFCVDowngrade(conn);
+    };
+}
+
+const downgradeOnDiskChangesTests = [
+    new dummyTest(),
+];
+
+function runStandaloneTest() {
+    jsTestLog("Running standalone test");
+
+    let conn;
+    let adminDB;
+
+    // A 'latest' binary standalone should default to 'latestFCV'.
+    conn = MongoRunner.runMongod({dbpath: dbpath, binVersion: latest});
+    assert.neq(
+        null, conn, "mongod was unable to start up with version=" + latest + " and no data files");
+    adminDB = conn.getDB("admin");
+    checkFCV(adminDB, latestFCV);
+
+    jsTestLog("Introducing on-disk changes to be downgraded in FCV downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.onDiskChangesBeforeDowngrade(conn);
+    }
+
+    jsTestLog(
+        "Test that setFeatureCompatibilityVersion succeeds with {downgradeOnDiskChanges: true}");
+    assert.commandWorked(adminDB.runCommand(
+        {setFeatureCompatibilityVersion: lastContinuousFCV, downgradeOnDiskChanges: true}));
+    checkFCV(adminDB, lastContinuousFCV);
+    checkLog.contains(conn, "Downgrading on-disk format");
+
+    jsTestLog("Validating on-disk changes after FCV downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.validateAfterFCVDowngrade(conn);
+    }
+
+    MongoRunner.stopMongod(conn);
+
+    // Test that the node can restart with a last-continuous binary.
+    conn = MongoRunner.runMongod({dbpath: dbpath, binVersion: lastContinuous, noCleanData: true});
+    assert.neq(null,
+               conn,
+               "mongod was unable to start up with binary version=" + lastContinuous +
+                   " and featureCompatibilityVersion=" + lastContinuousFCV);
+    adminDB = conn.getDB("admin");
+    checkFCV(adminDB, lastContinuousFCV);
+
+    jsTestLog("Validating on-disk changes after binary downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.validateAfterBinaryDowngrade(conn);
+    }
+
+    MongoRunner.stopMongod(conn);
+
+    // Test that the node can restart with a latest binary.
+    conn = MongoRunner.runMongod({dbpath: dbpath, binVersion: latest, noCleanData: true});
+    assert.neq(null,
+               conn,
+               "mongod was unable to start up with binary version=" + latest +
+                   " and featureCompatibilityVersion=" + lastContinuousFCV);
+    adminDB = conn.getDB("admin");
+    checkFCV(adminDB, lastContinuousFCV);
+
+    // Test that the FCV can be upgraded back to 'latestFCV'.
+    assert.commandWorked(adminDB.runCommand({setFeatureCompatibilityVersion: latestFCV}));
+    checkFCV(adminDB, latestFCV);
+
+    MongoRunner.stopMongod(conn);
+}
+
+function runReplicaSetTest() {
+    jsTestLog("Running replica set test");
+
+    // 'latest' binary replica set.
+    let rst = new ReplSetTest({nodes: 2, nodeOpts: {binVersion: latest}});
+    rst.startSet();
+    rst.initiateWithHighElectionTimeout();
+    let primaryAdminDB = rst.getPrimary().getDB("admin");
+    let secondaryAdminDB = rst.getSecondary().getDB("admin");
+
+    // FCV should default to 'latestFCV' on primary and secondary in a 'latest' binary replica set.
+    checkFCV(primaryAdminDB, latestFCV);
+    rst.awaitReplication();
+    checkFCV(secondaryAdminDB, latestFCV);
+
+    jsTestLog("Introducing on-disk changes to be downgraded in FCV downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.onDiskChangesBeforeDowngrade(rst.getPrimary());
+    }
+
+    jsTestLog(
+        "Test that setFeatureCompatibilityVersion succeeds with {downgradeOnDiskChanges: true} " +
+        "and propogates to the secondary");
+    assert.commandWorked(primaryAdminDB.runCommand(
+        {setFeatureCompatibilityVersion: lastContinuousFCV, downgradeOnDiskChanges: true}));
+    checkFCV(primaryAdminDB, lastContinuousFCV);
+    rst.awaitReplication();
+    checkFCV(secondaryAdminDB, lastContinuousFCV);
+
+    jsTestLog("Validating on-disk changes after FCV downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.validateAfterFCVDowngrade(rst.getPrimary());
+    }
+
+    // Test that the cluster can restart with a last-continuous binary.
+    rst.upgradeSet({binVersion: lastContinuous});
+    primaryAdminDB = rst.getPrimary().getDB("admin");
+    secondaryAdminDB = rst.getSecondary().getDB("admin");
+    checkFCV(primaryAdminDB, lastContinuousFCV);
+    checkFCV(secondaryAdminDB, lastContinuousFCV);
+
+    jsTestLog("Validating on-disk changes after binary downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.validateAfterBinaryDowngrade(rst.getPrimary());
+    }
+
+    // Test that the cluster can restart with a latest binary.
+    rst.upgradeSet({binVersion: latest});
+    primaryAdminDB = rst.getPrimary().getDB("admin");
+    secondaryAdminDB = rst.getSecondary().getDB("admin");
+    checkFCV(primaryAdminDB, lastContinuousFCV);
+    checkFCV(secondaryAdminDB, lastContinuousFCV);
+
+    // Test that the FCV can be upgraded back to 'latestFCV'.
+    assert.commandWorked(primaryAdminDB.runCommand({setFeatureCompatibilityVersion: latestFCV}));
+    checkFCV(primaryAdminDB, latestFCV);
+    rst.awaitReplication();
+    checkFCV(secondaryAdminDB, latestFCV);
+
+    rst.stopSet();
+}
+
+function runShardingTest() {
+    jsTestLog("Running sharding test");
+
+    // A 'latest' binary cluster started with clean data files will set FCV to 'latestFCV'.
+    let st =
+        new ShardingTest({shards: {rs0: {nodes: [{binVersion: latest}, {binVersion: latest}]}}});
+    let mongosAdminDB = st.s.getDB("admin");
+    let configPrimaryAdminDB = st.configRS.getPrimary().getDB("admin");
+    let shardPrimaryAdminDB = st.rs0.getPrimary().getDB("admin");
+
+    checkFCV(configPrimaryAdminDB, latestFCV);
+    checkFCV(shardPrimaryAdminDB, latestFCV);
+
+    jsTestLog("Introducing on-disk changes to be downgraded in FCV downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.onDiskChangesBeforeDowngrade(st.s);
+    }
+
+    jsTestLog(
+        "Test that setFeatureCompatibilityVersion succeeds with {downgradeOnDiskChanges: true} " +
+        "on mongos");
+    assert.commandWorked(mongosAdminDB.runCommand(
+        {setFeatureCompatibilityVersion: lastContinuousFCV, downgradeOnDiskChanges: true}));
+
+    // FCV propagates to config and shard.
+    checkFCV(configPrimaryAdminDB, lastContinuousFCV);
+    checkFCV(shardPrimaryAdminDB, lastContinuousFCV);
+
+    jsTestLog("Validating on-disk changes after FCV downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.validateAfterFCVDowngrade(st.s);
+    }
+
+    // Test that the cluster can restart with a last-continuous binary.
+    st.upgradeCluster(lastContinuous, {waitUntilStable: true});
+    configPrimaryAdminDB = st.configRS.getPrimary().getDB("admin");
+    shardPrimaryAdminDB = st.rs0.getPrimary().getDB("admin");
+    checkFCV(configPrimaryAdminDB, lastContinuousFCV);
+    checkFCV(shardPrimaryAdminDB, lastContinuousFCV);
+
+    jsTestLog("Validating on-disk changes after binary downgrade");
+    for (let test of downgradeOnDiskChangesTests) {
+        test.validateAfterBinaryDowngrade(st.s);
+    }
+
+    // Test that the cluster can restart with a latest binary.
+    st.upgradeCluster(latest, {waitUntilStable: true});
+    configPrimaryAdminDB = st.configRS.getPrimary().getDB("admin");
+    shardPrimaryAdminDB = st.rs0.getPrimary().getDB("admin");
+    checkFCV(configPrimaryAdminDB, lastContinuousFCV);
+    checkFCV(shardPrimaryAdminDB, lastContinuousFCV);
+
+    // Test that the FCV can be upgraded back to 'latestFCV'.
+    mongosAdminDB = st.s.getDB("admin");
+    assert.commandWorked(mongosAdminDB.runCommand({setFeatureCompatibilityVersion: latestFCV}));
+    checkFCV(configPrimaryAdminDB, latestFCV);
+    checkFCV(shardPrimaryAdminDB, latestFCV);
+
+    st.stop();
+}
+
+runStandaloneTest();
+runReplicaSetTest();
+runShardingTest();
+})();