mongodb/jstests/noPassthrough/timestamp_index_builds.js

/**
 * This test exercises a few important properties of timestamping index builds. First, it ensures
 * background index builds on primaries and secondaries timestamp both `init` and `commit`
 * operations on the catalog.
 *
 * Second, this test ensures the entire index build is ahead of the majority point. Thus when
 * restarting as a standalone, those indexes are not observed. When restarted with `--replSet`,
 * the indexes will be rebuilt. Currently performing a background index build at startup before
 * the logical clock is initialized will fail to timestamp index completion. The code currently
 * fixes this by foregrounding those index builds. We can observe the correctness of this behavior
 * by once again restarting the node as a standalone and not seeing any evidence of the second
 * index.
 *
 * This test does not guarantee that background index builds are foregrounded to correct
 * timestamping, merely that the catalog state is not corrupted due to the existence of background
 * index builds.
 *
 * @tags: [requires_replication, requires_persistence]
 */
(function() {
    "use strict";

    const rst = new ReplSetTest({
        name: "timestampingIndexBuilds",
        nodes: 2,
        nodeOptions:
            {setParameter: {logComponentVerbosity: tojsononeline({storage: {recovery: 2}})}}
    });
    const nodes = rst.startSet();
    rst.initiate();

    if (!rst.getPrimary().adminCommand("serverStatus").storageEngine.supportsSnapshotReadConcern) {
        // Only snapshotting storage engines require correct timestamping of index builds.
        rst.stopSet();
        return;
    }

    function getColl(conn) {
        return conn.getDB("timestampingIndexBuild")["coll"];
    }

    let coll = getColl(rst.getPrimary());

    // Create a collection and wait for the stable timestamp to exceed its creation on both nodes.
    assert.commandWorked(
        coll.insert({}, {writeConcern: {w: "majority", wtimeout: rst.kDefaultTimeoutMS}}));

    // Wait for the stable timestamp to match the latest oplog entry on both nodes.
    rst.awaitLastOpCommitted();

    // Disable snapshotting on all members of the replica set so that further operations do not
    // enter the majority snapshot.
    nodes.forEach(node => assert.commandWorked(node.adminCommand(
                      {configureFailPoint: "disableSnapshotting", mode: "alwaysOn"})));

    assert.commandWorked(coll.createIndexes([{foo: 1}], {background: true}));
    rst.awaitReplication();

    rst.stopSet(undefined, true);

    // The `disableSnapshotting` failpoint is no longer in effect. Bring up and analyze each node
    // separately. The client does not need to perform any writes from here on out.
    for (let nodeIdx = 0; nodeIdx < 2; ++nodeIdx) {
        let node = nodes[nodeIdx];
        let nodeIdentity = tojsononeline({nodeIdx: nodeIdx, dbpath: node.dbpath, port: node.port});

        // Bringing up the node as a standalone should only find the `_id` index.
        {
            jsTestLog("Starting as a standalone. Ensure only the `_id` index exists. Node: " +
                      nodeIdentity);
            let conn = rst.start(nodeIdx, {noReplSet: true, noCleanData: true});
            assert.neq(null, conn, "failed to restart node");
            assert.eq(1, getColl(conn).getIndexes().length);
            rst.stop(nodeIdx);
        }

        // Bringing up the node with `--replSet` will run oplog recovery. The `foo` index will be
        // rebuilt, but not become "stable".
        {
            jsTestLog("Starting as a replica set. Both indexes should exist. Node: " +
                      nodeIdentity);
            let conn = rst.start(nodeIdx, {startClean: false}, true);
            conn.setSlaveOk();
            assert.eq(2, getColl(conn).getIndexes().length);
            rst.stop(nodeIdx);
        }

        // Restarting the node as a standalone once again only shows the `_id` index.
        {
            jsTestLog(
                "Starting as a standalone after replication startup recovery. Ensure only the `_id` index exists. Node: " +
                nodeIdentity);
            let conn = rst.start(nodeIdx, {noReplSet: true, noCleanData: true});
            assert.neq(null, conn, "failed to restart node");
            assert.eq(1, getColl(conn).getIndexes().length);
            rst.stop(nodeIdx);
        }
    }

    rst.stopSet();
}());