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/**
* Tests that "atClusterTime" is supported by the "dbHash" command.
* @tags: [uses_transactions]
*/
(function() {
"use strict";
const rst = new ReplSetTest({nodes: 2});
rst.startSet();
const replSetConfig = rst.getReplSetConfig();
replSetConfig.members[1].priority = 0;
rst.initiate(replSetConfig);
const primary = rst.getPrimary();
const secondary = rst.getSecondary();
const session = primary.startSession({causalConsistency: false});
const db = session.getDatabase("test");
let txnNumber = 0;
// We also prevent all nodes in the replica set from advancing oldest_timestamp. This ensures
// that the snapshot associated with 'clusterTime' is retained for the duration of this test.
rst.nodes.forEach(conn => {
assert.commandWorked(conn.adminCommand({
configureFailPoint: "WTPreserveSnapshotHistoryIndefinitely",
mode: "alwaysOn",
}));
});
// We insert a document and save the md5sum associated with the opTime of that write.
assert.commandWorked(db.mycoll.insert({_id: 1}, {writeConcern: {w: "majority"}}));
const clusterTime = db.getSession().getOperationTime();
session.startTransaction({readConcern: {level: "snapshot", atClusterTime: clusterTime}});
let res = assert.commandWorked(db.runCommand({dbHash: 1}));
session.commitTransaction();
const hash1 = {collections: res.collections, md5: res.md5};
// We insert another document to ensure the collection's contents have a different md5sum now.
// We use a w=majority write concern to ensure that the insert has also been applied on the
// secondary by the time we go to run the dbHash command later. This avoids a race where the
// replication subsystem could be applying the insert operation when the dbHash command is run
// on the secondary.
assert.commandWorked(db.mycoll.insert({_id: 2}, {writeConcern: {w: "majority"}}));
// However, using atClusterTime to read at the opTime of the first insert should return the same
// md5sum as it did originally.
session.startTransaction({readConcern: {level: "snapshot", atClusterTime: clusterTime}});
res = assert.commandWorked(db.runCommand({dbHash: 1}));
session.commitTransaction();
const hash2 = {collections: res.collections, md5: res.md5};
assert.eq(hash1, hash2, "primary returned different dbhash after second insert");
{
const secondarySession = secondary.startSession({causalConsistency: false});
const secondaryDB = secondarySession.getDatabase("test");
// Using atClusterTime to read at the opTime of the first insert should return the same
// md5sum on the secondary as it did on the primary.
secondarySession.startTransaction(
{readConcern: {level: "snapshot", atClusterTime: clusterTime}});
res = assert.commandWorked(secondaryDB.runCommand({dbHash: 1}));
secondarySession.commitTransaction();
const secondaryHash = {collections: res.collections, md5: res.md5};
assert.eq(hash1, secondaryHash, "primary and secondary have different dbhash");
secondarySession.endSession();
}
{
const otherSession = primary.startSession({causalConsistency: false});
const otherDB = otherSession.getDatabase("test");
// We perform another insert inside a separate transaction to cause a MODE_IX lock to be
// held on the collection.
otherSession.startTransaction();
assert.commandWorked(otherDB.mycoll.insert({_id: 3}));
// It should be possible to run the "dbHash" command with "atClusterTime" concurrently.
session.startTransaction({readConcern: {level: "snapshot", atClusterTime: clusterTime}});
res = assert.commandWorked(db.runCommand({dbHash: 1}));
session.commitTransaction();
const hash3 = {collections: res.collections, md5: res.md5};
assert.eq(hash1, hash3, "primary returned different dbhash after third insert");
// However, the "dbHash" command should block behind the transaction if "atClusterTime"
// wasn't specified.
res = assert.commandFailedWithCode(db.runCommand({dbHash: 1, maxTimeMS: 1000}),
ErrorCodes.MaxTimeMSExpired);
otherSession.abortTransaction();
otherSession.endSession();
}
{
const otherSession = primary.startSession({causalConsistency: false});
const otherDB = otherSession.getDatabase("test");
// We create another collection inside a separate session to modify the collection catalog
// at an opTime later than 'clusterTime'. This prevents further usage of the snapshot
// associated with 'clusterTime' for snapshot reads.
assert.commandWorked(otherDB.runCommand({create: "mycoll2"}));
session.startTransaction({readConcern: {level: "snapshot", atClusterTime: clusterTime}});
assert.commandFailedWithCode(db.runCommand({dbHash: 1}), ErrorCodes.SnapshotUnavailable);
session.abortTransaction();
otherSession.endSession();
}
session.endSession();
rst.stopSet();
})();
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