mongodb/jstests/replsets/change_stream_speculative_majority.js

/**
 * Test basic, steady-state replication change stream functionality with speculative majority reads.
 *
 * @tags: [uses_speculative_majority]
 */
(function() {
    "use strict";

    load("jstests/libs/write_concern_util.js");  // for [stop|restart]ServerReplication.

    const name = "change_stream_speculative_majority";
    const replTest = new ReplSetTest({
        name: name,
        nodes: [{}, {rsConfig: {priority: 0}}],
        nodeOptions: {enableMajorityReadConcern: 'false'}
    });
    replTest.startSet();
    replTest.initiate();

    const dbName = name;
    const collName = "coll";

    let primary = replTest.getPrimary();
    let secondary = replTest.getSecondary();
    let primaryDB = primary.getDB(dbName);
    let primaryColl = primaryDB[collName];

    // Open a change stream.
    let res = primaryDB.runCommand(
        {aggregate: collName, pipeline: [{$changeStream: {}}], cursor: {}, maxTimeMS: 5000});
    assert.commandWorked(res);
    let cursorId = res.cursor.id;

    // Insert a document on primary and let it majority commit.
    assert.commandWorked(primaryColl.insert({_id: 1}, {writeConcern: {w: "majority"}}));

    // Receive the first change event.
    res = primary.getDB(dbName).runCommand({getMore: cursorId, collection: collName});
    let changes = res.cursor.nextBatch;
    assert.eq(changes.length, 1);
    assert.eq(changes[0]["fullDocument"], {_id: 1});
    assert.eq(changes[0]["operationType"], "insert");

    // Save the resume token.
    let resumeToken = changes[0]["_id"];

    // This query should time out waiting for new results and return an empty batch.
    res = primary.getDB(dbName).runCommand(
        {getMore: cursorId, collection: collName, maxTimeMS: 5000});
    assert.eq(res.cursor.nextBatch, []);

    // Pause replication on the secondary so that writes won't majority commit.
    stopServerReplication(secondary);

    // Do a new write on primary.
    assert.commandWorked(primaryColl.insert({_id: 2}));

    // The change stream query should time out waiting for the new result to majority commit.
    res = primary.getDB(dbName).runCommand(
        {getMore: cursorId, collection: collName, maxTimeMS: 5000});
    assert.commandFailedWithCode(res, ErrorCodes.MaxTimeMSExpired);

    // An aggregate trying to resume a stream that includes the change should also time out.
    res = primaryDB.runCommand({
        aggregate: collName,
        pipeline: [{$changeStream: {resumeAfter: resumeToken}}],
        cursor: {},
        maxTimeMS: 5000
    });
    assert.commandFailedWithCode(res, ErrorCodes.MaxTimeMSExpired);

    // Resume the stream after restarting replication. We should now be able to see the new event.
    restartServerReplication(secondary);
    replTest.awaitReplication();

    // Re-open the stream, and receive the new event.
    res = primaryDB.runCommand(
        {aggregate: collName, pipeline: [{$changeStream: {resumeAfter: resumeToken}}], cursor: {}});
    assert.commandWorked(res);
    changes = res.cursor.firstBatch;
    assert.eq(changes.length, 1);
    assert.eq(changes[0]["fullDocument"], {_id: 2});
    assert.eq(changes[0]["operationType"], "insert");

    replTest.stopSet();
})();