mongo/jstests/replsets/rollback_collMod_PowerOf2Sizes.js

// Test that a rollback of collModding usePowerOf2Sizes and validator can be rolled back.
//
// If all data-bearing nodes in a replica set are using an ephemeral storage engine, the set will
// not be able to survive a scenario where all data-bearing nodes are down simultaneously. In such a
// scenario, none of the members will have any data, and upon restart will each look for a member to
// inital sync from, so no primary will be elected. This test induces such a scenario, so cannot be
// run on ephemeral storage engines.
// @tags: [requires_persistence]
(function() {
"use strict";

function getOptions(conn) {
    return conn.getDB(name).foo.exists().options;
}

// Set up a set and grab things for later.
var name = "rollback_collMod_PowerOf2Sizes";
var replTest = new ReplSetTest({name: name, nodes: 3});
var nodes = replTest.nodeList();
var conns = replTest.startSet();
replTest.initiate({"_id": name,
                   "members": [
                       { "_id": 0, "host": nodes[0] },
                       { "_id": 1, "host": nodes[1] },
                       { "_id": 2, "host": nodes[2], arbiterOnly: true}]
                  });
// Get master and do an initial write.
var master = replTest.getPrimary();
var a_conn = master;
var slaves = replTest.liveNodes.slaves;
var b_conn = slaves[0];
var AID = replTest.getNodeId(a_conn);
var BID = replTest.getNodeId(b_conn);

// Create collection with custom options.
var originalCollectionOptions = {flags: 0,
                                 validator: {x: {$exists: 1}},
                                 validationLevel: "moderate",
                                 validationAction: "warn"};
assert.commandWorked(a_conn.getDB(name).createCollection('foo', originalCollectionOptions));

var options = {writeConcern: {w: 2, wtimeout: 60000}, upsert: true};
assert.writeOK(a_conn.getDB(name).foo.insert({x: 1}, options));

assert.eq(getOptions(a_conn), originalCollectionOptions);
assert.eq(getOptions(b_conn), originalCollectionOptions);

// Stop the slave so it never sees the collMod.
replTest.stop(BID);

// Run the collMod only on A.
assert.commandWorked(a_conn.getDB(name).runCommand({collMod: "foo",
                                                    usePowerOf2Sizes: false,
                                                    noPadding: true,
                                                    validator: {a: 1},
                                                    validationLevel: "moderate",
                                                    validationAction: "warn"}));
assert.eq(getOptions(a_conn), {flags: 2,
                               validator: {a: 1},
                               validationLevel: "moderate",
                               validationAction: "warn"});

// Shut down A and fail over to B.
replTest.stop(AID);
replTest.restart(BID);
master = replTest.getPrimary();
assert.eq(b_conn.host, master.host, "b_conn assumed to be master");
b_conn = master;

// Do a write on B so that A will have to roll back.
options = {writeConcern: {w: 1, wtimeout: 60000}, upsert: true};
assert.writeOK(b_conn.getDB(name).foo.insert({x: 2}, options));

// Restart A, which should rollback the collMod before becoming primary.
replTest.restart(AID);
try {
    b_conn.adminCommand({replSetStepDown: 60, secondaryCatchUpPeriodSecs: 60});
}
catch (e) {
    // Ignore network disconnect.
}
replTest.waitForState(a_conn, ReplSetTest.State.PRIMARY);
assert.eq(getOptions(a_conn), originalCollectionOptions);
}());