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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/**
* Test that transactions are only allowed on primaries, and prohibited from running on secondaries.
*
* @tags: [uses_transactions]
*/
(function() {
"use strict";
// In 4.0, we allow read-only transactions on secondaries when test commands are enabled, so we
// disable them in this test, to test that transactions on secondaries will be disallowed
// for production users.
jsTest.setOption('enableTestCommands', false);
TestData.authenticationDatabase = "local";
const dbName = "test";
const collName = "transactions_only_allowed_on_primaries";
// Start up the replica set. We want a stable topology, so make the secondary unelectable.
const replTest = new ReplSetTest({name: collName, nodes: 2});
replTest.startSet();
let config = replTest.getReplSetConfig();
config.members[1].priority = 0;
replTest.initiate(config);
const primary = replTest.getPrimary();
const secondary = replTest.getSecondary();
// Set slaveOk=true so that normal read commands would be allowed on the secondary.
secondary.setSlaveOk(true);
// Create a test collection that we can run commands against.
const primaryDB = primary.getDB(dbName);
assert.commandWorked(primary.getDB(dbName).createCollection(collName));
assert.commandWorked(primaryDB.runCommand({
createIndexes: collName,
indexes: [
{name: "geo_2d", key: {geo: "2d"}},
{key: {haystack: "geoHaystack", a: 1}, name: "haystack_geo", bucketSize: 1}
]
}));
replTest.awaitLastOpCommitted();
/**
* Verify that all given commands are disallowed from starting a transaction on a secondary by
* checking that each command fails with the expected error code.
*/
function testCommands(session, commands, expectedErrorCode, readPref) {
const sessionDb = session.getDatabase(dbName);
for (let i = 0; i < commands.length; i++) {
session.startTransaction();
// Use a read preference that would normally allow read commands to run on secondaries.
if (readPref !== null) {
session.getOptions().setReadPreference(readPref);
}
const cmdObject = commands[i];
jsTestLog("Trying to start transaction on secondary with command: " +
tojson(cmdObject));
assert.commandFailedWithCode(sessionDb.runCommand(cmdObject), expectedErrorCode);
// Call abort for good measure, even though the transaction should have already been
// aborted on the server.
session.abortTransaction();
}
}
//
// Make sure transactions are disallowed on secondaries.
//
// Initiate a session on the secondary.
const sessionOptions = {causalConsistency: false};
const secondarySession = secondary.getDB(dbName).getMongo().startSession(sessionOptions);
// Test read commands that are supported in transactions.
let readCommands = [
{find: collName},
{aggregate: collName, pipeline: [{$project: {_id: 1}}], cursor: {}},
{distinct: collName, key: "_id"},
{geoSearch: collName, near: [0, 0]}
];
jsTestLog("Testing read commands.");
// Make sure read commands can not start transactions with any supported read preference.
testCommands(secondarySession, readCommands, ErrorCodes.NotMaster, "secondary");
testCommands(secondarySession, readCommands, ErrorCodes.NotMaster, "secondaryPreferred");
testCommands(secondarySession, readCommands, ErrorCodes.NotMaster, "primaryPreferred");
testCommands(secondarySession, readCommands, ErrorCodes.NotMaster, null);
// Test one write command. Normal write commands should already be
// disallowed on secondaries so we don't test them exhaustively here.
let writeCommands = [{insert: collName, documents: [{_id: 0}]}];
jsTestLog("Testing write commands.");
testCommands(secondarySession, writeCommands, ErrorCodes.NotMaster, "secondary");
secondarySession.endSession();
//
// Make sure transactions are allowed on primaries with any valid read preference.
//
const primarySession = primary.getDB(dbName).getMongo().startSession(sessionOptions);
const primarySessionDb = primarySession.getDatabase(dbName);
primarySession.startTransaction();
assert.commandWorked(
primarySessionDb.runCommand({find: collName, $readPreference: {mode: "primary"}}));
primarySession.commitTransaction();
primarySession.startTransaction();
assert.commandWorked(
primarySessionDb.runCommand({find: collName, $readPreference: {mode: "primaryPreferred"}}));
primarySession.commitTransaction();
primarySession.startTransaction();
assert.commandWorked(primarySessionDb.runCommand(
{find: collName, $readPreference: {mode: "secondaryPreferred"}}));
primarySession.commitTransaction();
primarySession.startTransaction();
assert.commandWorked(
primarySessionDb.runCommand({find: collName, $readPreference: {mode: "nearest"}}));
primarySession.commitTransaction();
primarySession.endSession();
replTest.stopSet();
}());
|
