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/**
* Tests that index builds don't block on operations that conflict because they are in a prepared
* state.
*
* @tags: [
* requires_document_locking,
* requires_replication,
* two_phase_index_builds_unsupported,
* uses_prepare_transaction,
* uses_transactions,
* ]
*/
(function() {
"use strict";
load("jstests/core/txns/libs/prepare_helpers.js"); // for PrepareHelpers
load("jstests/noPassthrough/libs/index_build.js"); // for IndexBuildTest
const replSetTest = new ReplSetTest({
name: "index_builds_ignore_prepare_conflicts",
nodes: [
{},
{rsConfig: {priority: 0}},
],
});
replSetTest.startSet();
replSetTest.initiate();
const primary = replSetTest.getPrimary();
const primaryDB = primary.getDB('test');
let numDocs = 10;
let setUp = function(coll) {
coll.drop();
let bulk = coll.initializeUnorderedBulkOp();
for (let i = 0; i < numDocs; i++) {
bulk.insert({i: i});
}
assert.commandWorked(bulk.execute());
};
/**
* Run a background index build, and depending on the provided node, 'conn', ensure that a
* prepared update does not introduce prepare conflicts on the index builder.
*/
let runTest = function(conn) {
const testDB = conn.getDB('test');
const collName = 'index_builds_ignore_prepare_conflicts';
const coll = primaryDB.getCollection(collName);
setUp(coll);
// Start and pause an index build.
IndexBuildTest.pauseIndexBuilds(conn);
const awaitBuild = IndexBuildTest.startIndexBuild(primary, coll.getFullName(), {i: 1});
const opId = IndexBuildTest.waitForIndexBuildToScanCollection(testDB, collName, 'i_1');
// This insert will block until the index build pauses and releases its exclusive lock.
// This guarantees that the subsequent transaction can immediately acquire a lock and not
// fail with a LockTimeout error.
assert.commandWorked(coll.insert({i: numDocs++}));
// Start a session and introduce a document that is in a prepared state, but should be
// ignored by the index build, at least until the transaction commits.
const session = primaryDB.getMongo().startSession();
const sessionDB = session.getDatabase('test');
const sessionColl = sessionDB.getCollection(collName);
session.startTransaction();
assert.commandWorked(sessionColl.update({i: 0}, {i: "prepared"}));
// Use w:1 because the secondary will be unable to replicate the prepare while an index
// build is running.
const prepareTimestamp = PrepareHelpers.prepareTransaction(session, {w: 1});
// Let the index build continue until just before it completes. Set the failpoint just
// before the second drain, which would take lock that conflicts with the prepared
// transaction and prevent the index build from completing entirely.
const failPointName = "hangAfterIndexBuildFirstDrain";
clearRawMongoProgramOutput();
assert.commandWorked(conn.adminCommand({configureFailPoint: failPointName, mode: "alwaysOn"}));
// Unpause the index build from the first failpoint so that it can resume and pause at the
// next failpoint.
IndexBuildTest.resumeIndexBuilds(conn);
assert.soon(() =>
rawMongoProgramOutput().indexOf("Hanging after index build first drain") >= 0);
// Right before the index build completes, ensure no prepare conflicts were hit.
IndexBuildTest.assertIndexBuildCurrentOpContents(testDB, opId, (op) => {
printjson(op);
assert.eq(undefined, op.prepareReadConflicts);
});
// Because prepare uses w:1, ensure it is majority committed before committing the
// transaction.
PrepareHelpers.awaitMajorityCommitted(replSetTest, prepareTimestamp);
// Commit the transaction before completing the index build, releasing locks which will
// allow the index build to complete.
assert.commandWorked(PrepareHelpers.commitTransaction(session, prepareTimestamp));
// Allow the index build to complete.
assert.commandWorked(conn.adminCommand({configureFailPoint: failPointName, mode: "off"}));
awaitBuild();
IndexBuildTest.waitForIndexBuildToStop(testDB, collName, "i_1");
assert.eq(numDocs, coll.count());
assert.eq(numDocs, coll.find().itcount());
};
runTest(replSetTest.getPrimary());
replSetTest.stopSet();
})();
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