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/**
* Tests that timestamped reads, reads with snapshot and afterClusterTime, wait for the prepare
* transaction oplog entry to be visible before choosing a read timestamp.
*
* @tags: [uses_transactions, uses_prepare_transaction]
*/
(function() {
'use strict';
load("jstests/libs/check_log.js");
load('jstests/core/txns/libs/prepare_helpers.js');
load('jstests/libs/parallel_shell_helpers.js');
TestData.dbName = 'test';
const baseCollName = 'timestamped_reads_wait_for_prepare_oplog_visibility';
const testDB = db.getSiblingDB(TestData.dbName);
TestData.failureTimeout = 1 * 1000; // 1 second.
TestData.successTimeout = 5 * 60 * 1000; // 5 minutes.
TestData.txnDoc = {_id: 1, x: 1};
TestData.otherDoc = {_id: 2, y: 7};
TestData.txnDocFilter = {_id: TestData.txnDoc._id};
TestData.otherDocFilter = {_id: TestData.otherDoc._id};
/**
* A function that accepts a 'readFunc' and a collection name. 'readFunc' accepts a collection
* name and returns an object with an 'oplogVisibility' test field and a 'prepareConflict' test
* field. This function is run in a separate thread and tests that oplog visibility blocks
* certain reads and that prepare conflicts block other types of reads.
*/
const readThreadFunc = function(readFunc, _collName) {
load("jstests/libs/check_log.js");
// Do not start reads until we are blocked in 'prepareTransaction'.
checkLog.contains(db.getMongo(), "hangAfterReservingPrepareTimestamp fail point enabled");
// Create a 'readFuncObj' from the 'readFunc'.
const readFuncObj = readFunc(_collName);
readFuncObj.oplogVisibility();
// Let the transaction finish preparing and wait for 'prepareTransaction' to complete.
assert.commandWorked(db.adminCommand(
{configureFailPoint: 'hangAfterReservingPrepareTimestamp', mode: 'off'}));
checkLog.contains(db.getMongo(), "command: prepareTransaction");
readFuncObj.prepareConflict();
};
function runTest(prefix, readFunc) {
// Reset the log history between tests.
assert.commandWorked(db.adminCommand({clearLog: 'global'}));
jsTestLog('Testing oplog visibility for ' + prefix);
const collName = baseCollName + '_' + prefix;
const testColl = testDB.getCollection(collName);
testColl.drop({writeConcern: {w: "majority"}});
assert.commandWorked(testDB.runCommand({create: collName, writeConcern: {w: 'majority'}}));
assert.commandWorked(testDB.adminCommand(
{configureFailPoint: 'hangAfterReservingPrepareTimestamp', mode: 'alwaysOn'}));
// Insert a document for the transaction.
assert.commandWorked(testColl.insert(TestData.txnDoc));
// Insert a document untouched by the transaction.
assert.commandWorked(testColl.insert(TestData.otherDoc, {writeconcern: {w: "majority"}}));
// Start a transaction with a single update on the 'txnDoc'.
const session = db.getMongo().startSession({causalConsistency: false});
const sessionDB = session.getDatabase(TestData.dbName);
session.startTransaction({readConcern: {level: 'snapshot'}});
assert.commandWorked(sessionDB[collName].update(TestData.txnDoc, {$inc: {x: 1}}));
// We set the log level up to know when 'prepareTransaction' completes.
db.setLogLevel(1);
// Clear the log history to ensure we only see the most recent 'prepareTransaction'
// failpoint log message.
assert.commandWorked(db.adminCommand({clearLog: 'global'}));
const joinReadThread = startParallelShell(funWithArgs(readThreadFunc, readFunc, collName));
jsTestLog("Preparing the transaction for " + prefix);
const prepareTimestamp = PrepareHelpers.prepareTransaction(session);
db.setLogLevel(0);
joinReadThread({checkExitSuccess: true});
PrepareHelpers.commitTransaction(session, prepareTimestamp);
}
const snapshotRead = function(_collName) {
const _db = db.getSiblingDB(TestData.dbName);
const session = db.getMongo().startSession({causalConsistency: false});
const sessionDB = session.getDatabase(TestData.dbName);
const oplogVisibility = function() {
jsTestLog("Snapshot reads should not block on oplog visibility.");
session.startTransaction({readConcern: {level: 'snapshot'}});
let cursor = assert.commandWorked(sessionDB.runCommand({
find: _collName,
filter: TestData.txnDocFilter,
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.txnDoc], tojson(cursor));
assert.commandWorked(session.abortTransaction_forTesting());
session.startTransaction({readConcern: {level: 'snapshot'}});
cursor = assert.commandWorked(sessionDB.runCommand({
find: _collName,
filter: TestData.otherDocFilter,
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.otherDoc], tojson(cursor));
assert.commandWorked(session.abortTransaction_forTesting());
};
const prepareConflict = function() {
jsTestLog("Snapshot reads should block on prepared transactions for " +
"conflicting documents.");
session.startTransaction({readConcern: {level: 'snapshot'}});
let cursor = assert.commandFailedWithCode(sessionDB.runCommand({
find: _collName,
filter: TestData.txnDocFilter,
maxTimeMS: TestData.failureTimeout
}),
ErrorCodes.MaxTimeMSExpired);
assert.commandFailedWithCode(session.abortTransaction_forTesting(),
ErrorCodes.NoSuchTransaction);
jsTestLog("Snapshot reads should succeed on non-conflicting documents while a " +
"transaction is in prepare.");
session.startTransaction({readConcern: {level: 'snapshot'}});
cursor = assert.commandWorked(sessionDB.runCommand({
find: _collName,
filter: TestData.otherDocFilter,
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.otherDoc], tojson(cursor));
assert.commandWorked(session.abortTransaction_forTesting());
};
return {oplogVisibility: oplogVisibility, prepareConflict: prepareConflict};
};
const afterClusterTime = function(_collName) {
const _db = db.getSiblingDB(TestData.dbName);
// Advance the cluster time with an arbitrary other insert.
let res = assert.commandWorked(
_db.runCommand({insert: _collName, documents: [{advanceClusterTime: 1}]}));
assert(res.hasOwnProperty("$clusterTime"), tojson(res));
assert(res.$clusterTime.hasOwnProperty("clusterTime"), tojson(res));
const clusterTime = res.$clusterTime.clusterTime;
jsTestLog("Using afterClusterTime: " + clusterTime);
const oplogVisibility = function() {
jsTestLog("afterClusterTime reads should block on oplog visibility.");
assert.commandFailedWithCode(_db.runCommand({
find: _collName,
filter: TestData.txnDocFilter,
readConcern: {afterClusterTime: clusterTime},
maxTimeMS: TestData.failureTimeout
}),
ErrorCodes.MaxTimeMSExpired);
assert.commandFailedWithCode(_db.runCommand({
find: _collName,
filter: TestData.otherDocFilter,
readConcern: {afterClusterTime: clusterTime},
maxTimeMS: TestData.failureTimeout
}),
ErrorCodes.MaxTimeMSExpired);
};
const prepareConflict = function() {
jsTestLog("afterClusterTime reads should block on prepared transactions for " +
"conflicting documents.");
assert.commandFailedWithCode(_db.runCommand({
find: _collName,
filter: TestData.txnDocFilter,
readConcern: {afterClusterTime: clusterTime},
maxTimeMS: TestData.failureTimeout
}),
ErrorCodes.MaxTimeMSExpired);
jsTestLog("afterClusterTime reads should succeed on non-conflicting documents " +
"while transaction is in prepare.");
let cursor = assert.commandWorked(_db.runCommand({
find: _collName,
filter: TestData.otherDocFilter,
readConcern: {afterClusterTime: clusterTime},
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.otherDoc], tojson(cursor));
};
return {oplogVisibility: oplogVisibility, prepareConflict: prepareConflict};
};
const normalRead = function(_collName) {
const _db = db.getSiblingDB(TestData.dbName);
const oplogVisibility = function() {
jsTestLog("Ordinary reads should not block on oplog visibility.");
let cursor = assert.commandWorked(_db.runCommand({
find: _collName,
filter: TestData.txnDocFilter,
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.txnDoc], tojson(cursor));
cursor = assert.commandWorked(_db.runCommand({
find: _collName,
filter: TestData.otherDocFilter,
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.otherDoc], tojson(cursor));
};
const prepareConflict = function() {
jsTestLog("Ordinary reads should not block on prepared transactions.");
let cursor = assert.commandWorked(_db.runCommand({
find: _collName,
filter: TestData.txnDocFilter,
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.txnDoc], tojson(cursor));
cursor = assert.commandWorked(_db.runCommand({
find: _collName,
filter: TestData.otherDocFilter,
maxTimeMS: TestData.successTimeout
}));
assert.sameMembers(cursor.cursor.firstBatch, [TestData.otherDoc], tojson(cursor));
};
return {oplogVisibility: oplogVisibility, prepareConflict: prepareConflict};
};
runTest('normal_reads', normalRead);
runTest('snapshot_reads', snapshotRead);
runTest('afterClusterTime', afterClusterTime);
})();
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