84 lines
2.9 KiB
JavaScript
84 lines
2.9 KiB
JavaScript
/**
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* Confirms that a sharded $sample which employs the DSSampleFromRandomCursor optimization is
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* capable of yielding.
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*
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* @tags: [assumes_read_concern_unchanged, do_not_wrap_aggregations_in_facets,
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* requires_sharding]
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*/
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import {FixtureHelpers} from "jstests/libs/fixture_helpers.js";
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import {ShardingTest} from "jstests/libs/shardingtest.js";
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// Set up a 2-shard cluster. Configure 'internalQueryExecYieldIterations' on both shards such
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// that operations will yield on each PlanExecuter iteration.
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const st = new ShardingTest({
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name: jsTestName(),
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shards: 2,
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rs: {nodes: 1, setParameter: {internalQueryExecYieldIterations: 1}},
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});
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const mongosDB = st.s.getDB(jsTestName());
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const mongosColl = mongosDB.test;
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// Shard the test collection, split it at {_id: 0}, and move the upper chunk to shard1.
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st.shardColl(mongosColl, {_id: 1}, {_id: 0}, {_id: 0});
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// Insert enough documents on each shard to induce the $sample random-cursor optimization.
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for (let i = -150; i < 150; ++i) {
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assert.commandWorked(mongosColl.insert({_id: i}));
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}
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// Run the initial aggregate for the $sample stage.
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const cmdRes = assert.commandWorked(
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mongosDB.runCommand({
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aggregate: mongosColl.getName(),
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pipeline: [{$sample: {size: 3}}],
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comment: "$sample random",
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cursor: {batchSize: 0},
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}),
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);
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assert.eq(cmdRes.cursor.firstBatch.length, 0);
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// Force each shard to hang on yield to allow for currentOp capture.
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FixtureHelpers.runCommandOnEachPrimary({
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db: mongosDB.getSiblingDB("admin"),
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cmdObj: {
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configureFailPoint: "setYieldAllLocksHang",
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mode: "alwaysOn",
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data: {namespace: mongosColl.getFullName()},
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},
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});
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// Run $currentOp to confirm that the $sample getMore yields on both shards.
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const awaitShell = startParallelShell(async () => {
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const {FixtureHelpers} = await import("jstests/libs/fixture_helpers.js");
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assert.soon(
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() =>
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db
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.getSiblingDB("admin")
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.aggregate([
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{$currentOp: {}},
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{
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$match: {
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"cursor.originatingCommand.comment": "$sample random",
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planSummary: "QUEUED_DATA, MULTI_ITERATOR",
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numYields: {$gt: 0},
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},
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},
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])
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.itcount() === 2,
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);
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// Release the failpoint and allow the getMores to complete.
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FixtureHelpers.runCommandOnEachPrimary({
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db: db.getSiblingDB("admin"),
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cmdObj: {configureFailPoint: "setYieldAllLocksHang", mode: "off"},
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});
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}, mongosDB.getMongo().port);
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// Retrieve the results for the $sample aggregation.
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const sampleCursor = new DBCommandCursor(mongosDB, cmdRes);
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assert.eq(sampleCursor.toArray().length, 3);
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// Confirm that the parallel shell completes successfully, and tear down the cluster.
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awaitShell();
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st.stop();
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