Files
mongo/jstests/multiVersion/downgrade_replset.js
2017-09-27 23:23:46 -04:00

75 lines
2.7 KiB
JavaScript

// Test the downgrade of a replica set from latest version
// to last-stable version succeeds, while reads and writes continue.
load('./jstests/multiVersion/libs/multi_rs.js');
load('./jstests/libs/test_background_ops.js');
var newVersion = "latest";
var oldVersion = "last-stable";
var name = "replsetdowngrade";
var nodes = {
n1: {binVersion: newVersion},
n2: {binVersion: newVersion},
n3: {binVersion: newVersion}
};
function runDowngradeTest(protocolVersion) {
var rst = new ReplSetTest({name: name, nodes: nodes, waitForKeys: true});
rst.startSet();
var replSetConfig = rst.getReplSetConfig();
replSetConfig.protocolVersion = protocolVersion;
// Hard-code catchup timeout to be compatible with 3.4
replSetConfig.settings = {catchUpTimeoutMillis: 2000};
rst.initiate(replSetConfig);
var primary = rst.getPrimary();
var coll = "test.foo";
// We wait for the feature compatibility version to be set to "3.4" on all nodes of the replica
// set in order to ensure that all nodes can be successfully downgraded. This effectively allows
// us to emulate upgrading to the latest version with existing data files and then trying to
// downgrade back to 3.4.
assert.commandWorked(primary.adminCommand({setFeatureCompatibilityVersion: "3.4"}));
rst.awaitReplication();
jsTest.log("Inserting documents into collection.");
for (var i = 0; i < 10; i++) {
primary.getCollection(coll).insert({_id: i, str: "hello world"});
}
function insertDocuments(rsURL, coll) {
var coll = new Mongo(rsURL).getCollection(coll);
var count = 10;
while (!isFinished()) {
assert.writeOK(coll.insert({_id: count, str: "hello world"}));
count++;
}
}
jsTest.log("Starting parallel operations during downgrade..");
var joinFindInsert = startParallelOps(primary, insertDocuments, [rst.getURL(), coll]);
jsTest.log("Downgrading replica set..");
rst.upgradeSet({binVersion: oldVersion});
jsTest.log("Downgrade complete.");
// We save a reference to the old primary so that we can call reconnect() on it before
// joinFindInsert() would attempt to send the node an update operation that signals the parallel
// shell running the background operations to stop.
var oldPrimary = primary;
primary = rst.getPrimary();
printjson(rst.status());
// Since the old primary was restarted as part of the downgrade process, we explicitly reconnect
// to it so that sending it an update operation silently fails with an unchecked NotMaster error
// rather than a network error.
reconnect(oldPrimary.getDB("admin"));
joinFindInsert();
rst.stopSet();
}
runDowngradeTest(0);
runDowngradeTest(1);