mongo/jstests/sharding/query/agg/agg_explain_fmt.js

65 lines
3.2 KiB
JavaScript

/* This test ensures that explain of an aggregate through mongos has the intended format.
* @tags: [
* # $mergeCursors was added to explain output in 5.3.
* requires_fcv_80
* ]
*/
import {planHasStage} from "jstests/libs/query/analyze_plan.js";
import {ShardingTest} from "jstests/libs/shardingtest.js";
const st = new ShardingTest({shards: 2});
const mongosDB = st.s.getDB("test");
const coll = mongosDB.agg_explain_fmt;
// Insert documents with {_id: -5} to {_id: 4}.
assert.commandWorked(coll.insert(Array.from({length: 10}, (_, i) => ({_id: i - 5}))));
// Test that with an unsharded collection we don't get any kind of 'splitPipeline', just the
// normal explain with 'stages'.
let explain = coll.explain().aggregate([{$project: {a: 1}}]);
if (explain.hasOwnProperty("splitPipeline")) {
assert.eq(explain.splitPipeline, null, explain);
}
assert(planHasStage(mongosDB, explain, "PROJECTION_SIMPLE"), explain);
// Now shard the collection by _id and move a chunk to each shard.
st.shardColl(coll, {_id: 1}, {_id: 0}, {_id: 0});
// Test that we now have a split pipeline with information about what pipeline ran on each
// shard.
explain = coll.explain().aggregate([{$project: {a: 1}}]);
assert(explain.hasOwnProperty("splitPipeline"), explain);
assert(explain.splitPipeline.hasOwnProperty("shardsPart"), explain.splitPipeline);
assert(explain.splitPipeline.hasOwnProperty("mergerPart"), explain.splitPipeline);
assert(explain.hasOwnProperty("shards"), explain);
for (let shardId in explain.shards) {
const shardExplain = explain.shards[shardId];
assert(shardExplain.hasOwnProperty("explainVersion"));
assert(shardExplain.hasOwnProperty("host"), shardExplain);
assert(shardExplain.hasOwnProperty("stages") || shardExplain.hasOwnProperty("queryPlanner"), shardExplain);
}
// Test that the $mergeCursors stage is present in the mergerPart of the pipeline.
explain = coll.explain().aggregate([{$match: {mykey: {"$in": [0, 1, 3, 7]}}}, {"$sort": {favColor: 1}}, {$limit: 5}]);
assert(explain.hasOwnProperty("splitPipeline"), explain);
assert(explain.splitPipeline.hasOwnProperty("shardsPart"), explain.splitPipeline);
assert(explain.splitPipeline.hasOwnProperty("mergerPart"), explain.splitPipeline);
assert(explain.splitPipeline.mergerPart[0], explain.splitPipeline);
assert(explain.splitPipeline.mergerPart[0].hasOwnProperty("$mergeCursors"), explain.splitPipeline);
const mergeCursors = explain.splitPipeline.mergerPart[0]["$mergeCursors"];
assert.eq(mergeCursors.sort, {favColor: 1}, mergeCursors);
assert.eq(mergeCursors.compareWholeSortKey, false, mergeCursors);
assert(!mergeCursors.hasOwnProperty("remotes"), mergeCursors);
assert.eq(mergeCursors.tailableMode, "normal", mergeCursors);
assert.eq(mergeCursors.nss, "test.agg_explain_fmt", mergeCursors); // This test manually sets collection and db at the top.
assert.eq(mergeCursors.allowPartialResults, false, mergeCursors);
// Do a sharded explain from a mongod, not mongos, to ensure that it does not have a
// SHARDING_FILTER stage.");
const shardDB = st.shard0.getDB(mongosDB.getName());
explain = shardDB[coll.getName()].explain().aggregate([{$match: {}}]);
assert(!planHasStage(shardDB, explain.queryPlanner.winningPlan, "SHARDING_FILTER"), explain);
st.stop();