mongo/jstests/multiVersion/genericSetFCVUsage/upgrade_downgrade_while_creating_collection.js

/*
 * Tests that upgrade/downgrade works correctly even while creating a new collection.
 */
import {funWithArgs} from "jstests/libs/parallel_shell_helpers.js";
import {ReplSetTest} from "jstests/libs/replsettest.js";

function runTest(downgradeFCV) {
    jsTestLog("Running test with downgradeFCV: " + downgradeFCV);
    const rst = new ReplSetTest({nodes: 2});
    rst.startSet();

    // Rig the election so that the first node is always primary and that modifying the
    // featureCompatibilityVersion document doesn't need to wait for data to replicate.
    let replSetConfig = rst.getReplSetConfig();
    replSetConfig.members[1].priority = 0;
    replSetConfig.members[1].votes = 0;

    rst.initiate(replSetConfig);

    const primary = rst.getPrimary();
    const primaryDB = primary.getDB("test");

    for (let versions of [
        {from: downgradeFCV, to: latestFCV},
        {from: latestFCV, to: downgradeFCV},
    ]) {
        jsTestLog(
            "Changing FeatureCompatibilityVersion from " +
                versions.from +
                " to " +
                versions.to +
                " while creating a collection",
        );
        assert.commandWorked(primaryDB.adminCommand({setFeatureCompatibilityVersion: versions.from, confirm: true}));

        assert.commandWorked(
            primaryDB.adminCommand({configureFailPoint: "hangBeforeLoggingCreateCollection", mode: "alwaysOn"}),
        );
        primaryDB.mycoll.drop();

        let awaitCreateCollection;
        let awaitUpgradeFCV;

        try {
            awaitCreateCollection = startParallelShell(function () {
                assert.commandWorked(db.runCommand({create: "mycoll"}));
            }, primary.port);

            assert.soon(function () {
                return rawMongoProgramOutput('"id":20320').match(/\"id\":20320.*test.mycoll/); // Create Collection log
            });

            awaitUpgradeFCV = startParallelShell(
                funWithArgs(function (version) {
                    assert.commandWorked(db.adminCommand({setFeatureCompatibilityVersion: version, confirm: true}));
                }, versions.to),
                primary.port,
            );

            {
                let res;
                assert.soon(
                    function () {
                        res = assert.commandWorked(
                            primaryDB.adminCommand({getParameter: 1, featureCompatibilityVersion: 1}),
                        );
                        return (
                            res.featureCompatibilityVersion.version === versions.from &&
                            res.featureCompatibilityVersion.targetVersion === versions.new
                        );
                    },
                    function () {
                        return (
                            "targetVersion of featureCompatibilityVersion document wasn't " +
                            "updated on primary: " +
                            tojson(res)
                        );
                    },
                );
            }
        } finally {
            assert.commandWorked(
                primaryDB.adminCommand({configureFailPoint: "hangBeforeLoggingCreateCollection", mode: "off"}),
            );
        }

        awaitCreateCollection();
        awaitUpgradeFCV();
        rst.checkReplicatedDataHashes();
    }
    rst.stopSet();
}

runTest(lastContinuousFCV);
runTest(lastLTSFCV);