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// Tests the behaviour of an agg with $_requestReshardingResumeToken on an oplog which rolls over.
// @tags: [
// requires_journaling,
// requires_majority_read_concern,
// ]
(function() {
"use strict";
load('jstests/replsets/rslib.js'); // For getLatestOp, getFirstOplogEntry.
const oplogSize = 1; // size in MB
const rst = new ReplSetTest({nodes: 1, oplogSize: oplogSize});
rst.startSet();
rst.initiate();
const testDB = rst.getPrimary().getDB(jsTestName());
const testColl = testDB[jsTestName()];
const localDB = testDB.getSiblingDB("local");
const oplogColl = localDB.oplog.rs;
// Insert one document into the test collection.
const insertCmdRes = assert.commandWorked(testDB.runCommand(
{insert: testColl.getName(), documents: [{_id: 1}], writeConcern: {w: "majority"}}));
// Record the optime of the insert to resume from later in the test.
const resumeTimeFirstInsert = insertCmdRes.operationTime;
// Update the document to create another oplog entry.
assert.commandWorked(testColl.update({_id: 1}, {$set: {updated: true}}));
// Verify that an aggregation which requests a resharding resume token but does not include a filter
// on 'ts' is rejected.
assert.commandFailedWithCode(localDB.runCommand({
aggregate: oplogColl.getName(),
pipeline: [{$match: {ns: testColl.getFullName()}}],
cursor: {},
$_requestReshardingResumeToken: true
}),
ErrorCodes.InvalidOptions);
// Verify that we can start an aggregation from the timestamp that we took earlier, and that we see
// the subsequent update operation.
let aggCmdRes = assert.commandWorked(localDB.runCommand({
aggregate: oplogColl.getName(),
pipeline: [{$match: {ts: {$gt: resumeTimeFirstInsert}, ns: testColl.getFullName()}}],
cursor: {},
$_requestReshardingResumeToken: true
}));
const aggCmdCursor = new DBCommandCursor(localDB, aggCmdRes);
assert.soon(() => aggCmdCursor.hasNext());
let next = aggCmdCursor.next();
assert.eq(next.op, "u");
assert.eq(next.o2._id, 1);
// Confirm that we can begin an aggregation at a timestamp that precedes the start of the oplog, if
// the first entry in the oplog is the replica set initialization message.
const firstOplogEntry = getFirstOplogEntry(rst.getPrimary());
assert.eq(firstOplogEntry.o.msg, "initiating set");
assert.eq(firstOplogEntry.op, "n");
aggCmdRes = assert.commandWorked(localDB.runCommand({
aggregate: oplogColl.getName(),
pipeline: [{$match: {ts: {$gte: Timestamp(1, 1)}, ns: testColl.getFullName()}}],
cursor: {},
$_requestReshardingResumeToken: true
}));
const startAtDawnOfTimeCursor = new DBCommandCursor(localDB, aggCmdRes);
for (let expectedOp of [{op: "i", _id: 1}, {op: "u", _id: 1}]) {
assert.soon(() => startAtDawnOfTimeCursor.hasNext());
next = startAtDawnOfTimeCursor.next();
assert.eq(next.op, expectedOp.op);
assert.eq((next.o._id || next.o2._id), expectedOp._id);
}
// Roll over the entire oplog such that none of the events are still present.
const primaryNode = rst.getPrimary();
const mostRecentOplogEntry = getLatestOp(primaryNode);
assert.neq(mostRecentOplogEntry, null);
const largeStr = new Array(4 * 1024 * oplogSize).join('abcdefghi');
function oplogIsRolledOver() {
// The oplog has rolled over if the op that used to be newest is now older than the
// oplog's current oldest entry. Said another way, the oplog is rolled over when
// everything in the oplog is newer than what used to be the newest entry.
return bsonWoCompare(mostRecentOplogEntry.ts,
getFirstOplogEntry(primaryNode, {readConcern: "majority"}).ts) < 0;
}
while (!oplogIsRolledOver()) {
assert.commandWorked(testColl.insert({long_str: largeStr}, {writeConcern: {w: "majority"}}));
}
// Test that attempting to start from a timestamp that has already fallen off the oplog fails, if we
// specify $_requestReshardingResumeToken.
assert.commandFailedWithCode(localDB.runCommand({
aggregate: oplogColl.getName(),
pipeline: [{$match: {ts: {$gte: resumeTimeFirstInsert}, ns: testColl.getFullName()}}],
cursor: {},
$_requestReshardingResumeToken: true
}),
ErrorCodes.OplogQueryMinTsMissing);
assert.commandFailedWithCode(localDB.runCommand({
aggregate: oplogColl.getName(),
pipeline: [{$match: {ts: {$gte: Timestamp(1, 1)}, ns: testColl.getFullName()}}],
cursor: {},
$_requestReshardingResumeToken: true
}),
ErrorCodes.OplogQueryMinTsMissing);
// However, the same aggregation succeeds if we do not specify $_requestReshardingResumeToken. Since
// we have just rolled over the oplog, we may encounter a "CappedPositionLost" error, which can be
// safely retried.
assert.soon(() => {
let commandRes = localDB.runCommand({
aggregate: oplogColl.getName(),
pipeline: [{$match: {ts: {$gte: Timestamp(1, 1)}, ns: testColl.getFullName()}}],
cursor: {},
});
if (!commandRes.ok && commandRes.code == ErrorCodes.CappedPositionLost) {
jsTestLog("Encountered a CappedPositionLost error, retrying the command.");
return false;
}
assert.commandWorked(commandRes);
return true;
});
// Requesting resume tokens on a find command does not imply 'assertMinTsHasNotFallenOffOplog'.
// Since we have just rolled over the oplog, we may encounter a "CappedPositionLost" error, which
// can be safely retried.
assert.soon(() => {
let commandRes = localDB.runCommand({
find: oplogColl.getName(),
filter: {ts: {$gte: Timestamp(1, 1)}, ns: testColl.getFullName()},
tailable: true,
hint: {$natural: 1},
$_requestResumeToken: true
});
if (!commandRes.ok && commandRes.code == ErrorCodes.CappedPositionLost) {
jsTestLog("Encountered a CappedPositionLost error, retrying the command.");
return false;
}
assert.commandWorked(commandRes);
return true;
});
rst.stopSet();
})();
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