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/**
* Test setting minSnapshotHistoryWindowInSeconds at runtime and that server keeps history for up to
* minSnapshotHistoryWindowInSeconds.
*
* @tags: [requires_majority_read_concern, requires_replication]
*/
(function() {
"use strict";
const replSet = new ReplSetTest({nodes: 1});
replSet.startSet();
replSet.initiate();
const collName = "coll";
const primary = replSet.getPrimary();
const primaryDB = primary.getDB('test');
const historyWindowSecs = 10;
assert.commandWorked(primaryDB.adminCommand(
{setParameter: 1, minSnapshotHistoryWindowInSeconds: historyWindowSecs}));
const startTime = Date.now();
const insertTimestamp =
assert.commandWorked(primaryDB.runCommand({insert: collName, documents: [{_id: 0}]}))
.operationTime;
let nextId = 1;
// Test snapshot window with 1s margin.
const testMarginMS = 1000;
// Test that reading from a snapshot at insertTimestamp is valid for up to historyWindowSecs minus
// the testMarginMS (as a buffer) to avoid races between the client's snapshot read and the update
// of the oldest timestamp in the server.
const testWindowMS = historyWindowSecs * 1000 - testMarginMS;
while (Date.now() - startTime < testWindowMS) {
// Test that reading from a snapshot at insertTimestamp is still valid.
assert.commandWorked(primaryDB.runCommand(
{find: collName, readConcern: {level: "snapshot", atClusterTime: insertTimestamp}}));
// Perform writes to advance stable timestamp and oldest timestamp. We use majority writeConcern
// so that we can make sure the stable timestamp and the oldest timestamp are updated after each
// insert.
assert.commandWorked(primaryDB.runCommand(
{insert: collName, documents: [{_id: nextId}], writeConcern: {w: "majority"}}));
nextId++;
sleep(50);
}
// Sleep enough to make sure the insertTimestamp falls off the snapshot window.
sleep(testMarginMS * 2);
// Perform another majority write to advance the stable timestamp and the oldest timestamp again.
assert.commandWorked(primaryDB.runCommand(
{insert: collName, documents: [{_id: nextId}], writeConcern: {w: "majority"}}));
// Test that reading from a snapshot at insertTimestamp returns SnapshotTooOld.
assert.commandFailedWithCode(
primaryDB.runCommand(
{find: collName, readConcern: {level: "snapshot", atClusterTime: insertTimestamp}}),
ErrorCodes.SnapshotTooOld);
// Test that the SnapshotTooOld is recorded in serverStatus.
const serverStatusWT = assert.commandWorked(primaryDB.adminCommand({serverStatus: 1})).wiredTiger;
assert.eq(1,
serverStatusWT["snapshot-window-settings"]["total number of SnapshotTooOld errors"],
tojson(serverStatusWT));
replSet.stopSet();
})();
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