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
|
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
couchTests.delayed_commits = function(debug) {
var db = new CouchDB("test_suite_db", {"X-Couch-Full-Commit":"false"});
db.deleteDb();
db.createDb();
if (debug) debugger;
run_on_modified_server(
[{section: "couchdb",
key: "delayed_commits",
value: "true"}],
function () {
// By default, couchdb doesn't fully commit documents to disk right away,
// it waits about a second to batch the full commit flush along with any
// other updates. If it crashes or is restarted you may lose the most
// recent commits.
T(db.save({_id:"1",a:2,b:4}).ok);
T(db.open("1") != null);
restartServer();
T(db.open("1") == null); // lost the update.
// note if we waited > 1 sec before the restart, the doc would likely
// commit.
// Retry the same thing but with full commits on.
var db2 = new CouchDB("test_suite_db", {"X-Couch-Full-Commit":"true"});
T(db2.save({_id:"1",a:2,b:4}).ok);
T(db2.open("1") != null);
restartServer();
T(db2.open("1") != null);
// You can update but without committing immediately, and then ensure
// everything is commited in the last step.
T(db.save({_id:"2",a:2,b:4}).ok);
T(db.open("2") != null);
T(db.ensureFullCommit().ok);
restartServer();
T(db.open("2") != null);
// However, it's possible even when flushed, that the server crashed between
// the update and the commit, and you don't want to check to make sure
// every doc you updated actually made it to disk. So record the instance
// start time of the database before the updates and then check it again
// after the flush (the instance start time is returned by the flush
// operation). if they are the same, we know everything was updated
// safely.
// First try it with a crash.
var instanceStartTime = db.info().instance_start_time;
T(db.save({_id:"3",a:2,b:4}).ok);
T(db.open("3") != null);
restartServer();
var commitResult = db.ensureFullCommit();
T(commitResult.ok && commitResult.instance_start_time != instanceStartTime);
// start times don't match, meaning the server lost our change
T(db.open("3") == null); // yup lost it
// retry with no server restart
var instanceStartTime = db.info().instance_start_time;
T(db.save({_id:"4",a:2,b:4}).ok);
T(db.open("4") != null);
var commitResult = db.ensureFullCommit();
T(commitResult.ok && commitResult.instance_start_time == instanceStartTime);
// Successful commit, start times match!
restartServer();
T(db.open("4") != null);
});
// Now test that when we exceed the max_dbs_open, pending commits are safely
// written.
T(db.save({_id:"5",foo:"bar"}).ok);
var max = 2;
run_on_modified_server(
[{section: "couchdb",
key: "delayed_commits",
value: "true"},
{section: "couchdb",
key: "max_dbs_open",
value: max.toString()}],
function () {
for(var i=0; i<max; i++) {
var dbi = new CouchDB("test_suite_db" + i);
dbi.deleteDb();
dbi.createDb();
}
T(db.open("5").foo=="bar");
for(var i=0; i<max+1; i++) {
var dbi = new CouchDB("test_suite_db" + i);
dbi.deleteDb();
}
});
};
|