mirror of https://github.com/mongodb/mongo
80 lines
2.4 KiB
JavaScript
80 lines
2.4 KiB
JavaScript
/**
|
|
* Test the $sampleRate match expression.
|
|
* @tags: [
|
|
* # TODO(SERVER-60823): remove incompatible_with_gcov
|
|
* incompatible_with_gcov,
|
|
* ]
|
|
*/
|
|
(function() {
|
|
"use strict";
|
|
|
|
const coll = db.expression_sample_rate;
|
|
coll.drop();
|
|
|
|
print("Generating test collection...");
|
|
const N = 3000;
|
|
let i;
|
|
const bulk = coll.initializeUnorderedBulkOp();
|
|
for (i = 0; i < N; i++) {
|
|
bulk.insert({_id: i, v: 1});
|
|
}
|
|
assert.commandWorked(bulk.execute());
|
|
|
|
const p = 0.5;
|
|
const k = 1000;
|
|
|
|
// Average the number of docs sampled over k iterations.
|
|
const pipeline = [{$match: {$sampleRate: p}}, {$count: "n"}];
|
|
let nSampled = 0;
|
|
for (i = 0; i < k; i++) {
|
|
const resultArray = coll.aggregate(pipeline).toArray();
|
|
assert.eq(1, resultArray.length);
|
|
nSampled += resultArray[0]["n"];
|
|
}
|
|
const avg = nSampled / k;
|
|
print("Average docs sampled: ", avg);
|
|
|
|
// Test that the average number of sampled docs is within 10 standard deviations using the
|
|
// binomial distribution over k runs, 10 * sqrt(N * p * (1 - p) / k).
|
|
const mu = p * N;
|
|
const err = 10.0 * Math.sqrt(mu * (1 - p) / k);
|
|
assert.between(mu - err, avg, mu + err);
|
|
|
|
// Test that we accept 0.0 and 1.0.
|
|
let resultArray = coll.aggregate([{$match: {$sampleRate: 0.0}}]).toArray();
|
|
assert.eq(0, resultArray.length);
|
|
|
|
resultArray = coll.aggregate([{$match: {$sampleRate: 0}}]).toArray();
|
|
assert.eq(0, resultArray.length);
|
|
|
|
resultArray = coll.aggregate([{$match: {$sampleRate: 1.0}}, {$count: "n"}]).toArray();
|
|
assert.eq(1, resultArray.length);
|
|
assert.eq(resultArray[0]["n"], N);
|
|
|
|
resultArray = coll.aggregate([{$match: {$sampleRate: 1}}, {$count: "n"}]).toArray();
|
|
assert.eq(1, resultArray.length);
|
|
assert.eq(resultArray[0]["n"], N);
|
|
|
|
// Test parser failure cases.
|
|
assert.commandFailedWithCode(
|
|
db.runCommand({aggregate: coll.getName(), cursor: {}, pipeline: [{$match: {$sampleRate: -1}}]}),
|
|
ErrorCodes.BadValue);
|
|
|
|
assert.commandFailedWithCode(
|
|
db.runCommand(
|
|
{aggregate: coll.getName(), cursor: {}, pipeline: [{$match: {$sampleRate: -1.0}}]}),
|
|
ErrorCodes.BadValue);
|
|
|
|
assert.commandFailedWithCode(
|
|
db.runCommand(
|
|
{aggregate: coll.getName(), cursor: {}, pipeline: [{$match: {$sampleRate: 2.0}}]}),
|
|
ErrorCodes.BadValue);
|
|
|
|
assert.commandFailedWithCode(db.runCommand({
|
|
aggregate: coll.getName(),
|
|
cursor: {},
|
|
pipeline: [{$match: {$sampleRate: {$const: 0.25}}}]
|
|
}),
|
|
ErrorCodes.BadValue);
|
|
}());
|