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
|
/**
* Loading this file overrides DB.prototype.getCollection() with a function that attempts to shard
* the collection before returning it.
*
* The DB.prototype.getCollection() function is called whenever an undefined property is accessed
* on the db object.
*
* DBCollection.prototype.drop() function will re-shard any non-blacklisted collection that is
* dropped in a sharded cluster.
*/
(function() {
'use strict';
// Save a reference to the original getCollection method in the IIFE's scope.
// This scoping allows the original method to be called by the getCollection override below.
var originalGetCollection = DB.prototype.getCollection;
var originalDBCollectionDrop = DBCollection.prototype.drop;
var originalStartParallelShell = startParallelShell;
var testMayRunDropInParallel = false;
// Blacklisted namespaces that should not be sharded.
var blacklistedNamespaces = [
/\$cmd/,
/^admin\./,
/^config\./,
/\.system\./,
];
function shardCollection(collection) {
var db = collection.getDB();
var dbName = db.getName();
var fullName = collection.getFullName();
for (var ns of blacklistedNamespaces) {
if (fullName.match(ns)) {
return;
}
}
var res = db.adminCommand({enableSharding: dbName});
// enableSharding may only be called once for a database.
if (res.code !== ErrorCodes.AlreadyInitialized) {
assert.commandWorked(res, "enabling sharding on the '" + dbName + "' db failed");
}
res = db.adminCommand({shardCollection: fullName, key: {_id: 'hashed'}});
if (res.ok === 0 && testMayRunDropInParallel) {
// We ignore ConflictingOperationInProgress error responses from the
// "shardCollection" command if it's possible the test was running a "drop" command
// concurrently. We could retry running the "shardCollection" command, but tests
// that are likely to trigger this case are also likely running the "drop" command
// in a loop. We therefore just let the test continue with the collection being
// unsharded.
assert.commandFailedWithCode(res, ErrorCodes.ConflictingOperationInProgress);
print("collection '" + fullName +
"' failed to be sharded due to a concurrent drop operation");
} else {
assert.commandWorked(res, "sharding '" + fullName + "' with a hashed _id key failed");
}
}
DB.prototype.getCollection = function() {
var collection = originalGetCollection.apply(this, arguments);
// If the collection exists, there must have been a previous call to getCollection
// where we sharded the collection so there's no need to do it again.
if (collection.exists()) {
return collection;
}
// Attempt to enable sharding on database and collection if not already done.
shardCollection(collection);
return collection;
};
DBCollection.prototype.drop = function() {
var dropResult = originalDBCollectionDrop.apply(this, arguments);
// Attempt to enable sharding on database and collection if not already done.
shardCollection(this);
return dropResult;
};
// Tests may use a parallel shell to run the "drop" command concurrently with other
// operations. This can cause the "shardCollection" command to return a
// ConflictingOperationInProgress error response.
startParallelShell = function() {
testMayRunDropInParallel = true;
return originalStartParallelShell.apply(this, arguments);
};
}());
|
