mongodb/jstests/replsets/not_master_unacknowledged_write.js

/**
 * Test that a secondary hangs up on an unacknowledged write.
 */

(function() {
"use strict";

function getNotMasterUnackWritesCounter() {
    return assert.commandWorked(primaryDB.adminCommand({serverStatus: 1}))
        .metrics.repl.network.notMasterUnacknowledgedWrites;
}

const collName = "not_master_unacknowledged_write";

var rst = new ReplSetTest({nodes: [{}, {rsConfig: {priority: 0}}]});
rst.startSet();
rst.initiate();
var primary = rst.getPrimary();
var secondary = rst.getSecondary();
var primaryDB = primary.getDB("test");
var secondaryDB = secondary.getDB("test");
var primaryColl = primaryDB[collName];
var secondaryColl = secondaryDB[collName];

// Verify that reading from secondaries does not impact `notMasterUnacknowledgedWrites`.
const preReadingCounter = getNotMasterUnackWritesCounter();
jsTestLog("Reading from secondary ...");
[{name: "findOne", fn: () => secondaryColl.findOne()},
 {name: "distinct", fn: () => secondaryColl.distinct("item")},
 {name: "count", fn: () => secondaryColl.find().count()},
].map(({name, fn}) => {
    assert.doesNotThrow(fn);
    assert.eq(assert.commandWorked(secondary.getDB("admin").isMaster()).ismaster, false);
});
const postReadingCounter = getNotMasterUnackWritesCounter();
assert.eq(preReadingCounter, postReadingCounter);

jsTestLog("Primary on port " + primary.port + " hangs up on unacknowledged writes");
// Do each write method with unacknowledged write concern, "wc".
[{name: "insertOne", fn: (wc) => secondaryColl.insertOne({}, wc)},
 {name: "insertMany", fn: (wc) => secondaryColl.insertMany([{}], wc)},
 {name: "deleteOne", fn: (wc) => secondaryColl.deleteOne({}, wc)},
 {name: "deleteMany", fn: (wc) => secondaryColl.deleteMany({}, wc)},
 {name: "updateOne", fn: (wc) => secondaryColl.updateOne({}, {$set: {x: 1}}, wc)},
 {name: "updateMany", fn: (wc) => secondaryColl.updateMany({}, {$set: {x: 1}}, wc)},
 {name: "replaceOne", fn: (wc) => secondaryColl.replaceOne({}, {}, wc)},
].map(({name, fn}) => {
    var result = assert.throws(function() {
        // Provoke the server to hang up.
        fn({writeConcern: {w: 0}});
        // The connection is now broken and isMaster throws a network error.
        secondary.getDB("admin").isMaster();
    }, [], "network error from " + name);

    assert.includes(result.toString(),
                    "network error while attempting to run command 'isMaster'",
                    "after " + name);
});

// Unacknowledged write in progress when a stepdown occurs provokes a hangup.
assert.commandWorked(primaryDB.adminCommand({
    configureFailPoint: "hangAfterCollectionInserts",
    mode: "alwaysOn",
    data: {collectionNS: primaryColl.getFullName()}
}));

var command =
    `
      checkLog.contains(db.getMongo(), "hangAfterCollectionInserts fail point enabled");
      db.adminCommand({replSetStepDown: 60, force: true});`;

var awaitShell = startParallelShell(command, primary.port);

let failedUnackWritesBefore = getNotMasterUnackWritesCounter();

jsTestLog("Beginning unacknowledged insert");
primaryColl.insertOne({}, {writeConcern: {w: 0}});

jsTestLog("Step down primary on port " + primary.port);
awaitShell({checkExitSuccess: false});

jsTestLog("Unacknowledged insert during stepdown provoked disconnect");
var result = assert.throws(function() {
    primary.getDB("admin").isMaster();
}, [], "network");
assert.includes(result.toString(), "network error while attempting to run command 'isMaster'");

// Validate the number of unacknowledged writes failed due to step down resulted in network
// disconnection.
let failedUnackWritesAfter = getNotMasterUnackWritesCounter();
assert.eq(failedUnackWritesAfter, failedUnackWritesBefore + 1);

rst.stopSet();
})();