1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
/**
* Test resuming a change stream on a node other than the one it was started on. Accomplishes this
* by triggering a stepdown.
*/
// Checking UUID consistency uses cached connections, which are not valid across restarts or
// stepdowns.
TestData.skipCheckingUUIDsConsistentAcrossCluster = true;
(function() {
"use strict";
// For supportsMajorityReadConcern().
load("jstests/multiVersion/libs/causal_consistency_helpers.js");
load("jstests/libs/change_stream_util.js"); // For ChangeStreamTest.
load("jstests/libs/collection_drop_recreate.js"); // For assert[Drop|Create]Collection.
if (!supportsMajorityReadConcern()) {
jsTestLog("Skipping test since storage engine doesn't support majority read concern.");
return;
}
const st = new ShardingTest({
shards: 2,
rs: {nodes: 2, setParameter: {periodicNoopIntervalSecs: 1, writePeriodicNoops: true}}
});
const sDB = st.s.getDB("test");
const kCollName = "change_stream_failover";
for (let key of Object.keys(ChangeStreamTest.WatchMode)) {
const watchMode = ChangeStreamTest.WatchMode[key];
jsTestLog("Running test for mode " + watchMode);
const coll = assertDropAndRecreateCollection(sDB, kCollName);
const nDocs = 100;
// Split so ids < nDocs / 2 are for one shard, ids >= nDocs / 2 + 1 for another.
st.shardColl(coll,
{_id: 1}, // key
{_id: nDocs / 2}, // split
{_id: nDocs / 2 + 1}, // move
"test", // dbName
false // waitForDelete
);
// Be sure we'll only read from the primaries.
st.s.setReadPref("primary");
// Open a changeStream.
const cst = new ChangeStreamTest(ChangeStreamTest.getDBForChangeStream(watchMode, sDB));
let changeStream = cst.getChangeStream({watchMode: watchMode, coll: coll});
// Be sure we can read from the change stream. Write some documents that will end up on
// each shard. Use a bulk write to increase the chance that two of the writes get the same
// cluster time on each shard.
const bulk = coll.initializeUnorderedBulkOp();
const kIds = [];
for (let i = 0; i < nDocs / 2; i++) {
// Interleave elements which will end up on shard 0 with elements that will end up on
// shard 1.
kIds.push(i);
bulk.insert({_id: i});
kIds.push(i + nDocs / 2);
bulk.insert({_id: i + nDocs / 2});
}
// Use {w: "majority"} so that we're still guaranteed to be able to read after the
// failover.
assert.commandWorked(bulk.execute({w: "majority"}));
const firstChange = cst.getOneChange(changeStream);
// Make one of the primaries step down.
const oldPrimary = st.rs0.getPrimary();
const stepDownError = assert.throws(function() {
oldPrimary.adminCommand({replSetStepDown: 300, force: true});
});
assert(isNetworkError(stepDownError),
"replSetStepDown did not disconnect client; failed with " + tojson(stepDownError));
st.rs0.awaitNodesAgreeOnPrimary();
const newPrimary = st.rs0.getPrimary();
// Be sure the new primary is not the previous primary.
assert.neq(newPrimary.port, oldPrimary.port);
// Read the remaining documents from the original stream.
const docsFoundInOrder = [firstChange];
for (let i = 0; i < nDocs - 1; i++) {
const change = cst.getOneChange(changeStream);
assert.docEq(change.ns, {db: sDB.getName(), coll: coll.getName()});
assert.eq(change.operationType, "insert");
docsFoundInOrder.push(change);
}
// Assert that we found the documents we inserted (in any order).
assert.setEq(new Set(kIds), new Set(docsFoundInOrder.map(doc => doc.fullDocument._id)));
// Now resume using the resume token from the first change (which was read before the
// failover). The mongos should talk to the new primary.
const resumeCursor =
cst.getChangeStream({watchMode: watchMode, coll: coll, resumeAfter: firstChange._id});
// Be sure we can read the remaining changes in the same order as we read them initially.
cst.assertNextChangesEqual(
{cursor: resumeCursor, expectedChanges: docsFoundInOrder.splice(1)});
cst.cleanUp();
// Reset the original primary's election timeout.
assert.commandWorked(oldPrimary.adminCommand({replSetFreeze: 0}));
}
st.stop();
}());
|