New probabilistic sampler processor tests for legacy compatibility (#…

…32360) **Description:** Adds new hard-coded test of the TraceID hashing function in the probabilisticsamplerprocessor. This will ensure that changes do not inadvertently modify the hashing function or associated logic for spans. Note that the Logs sampler logic includes a test with exact counts of sampled log records, which serves the same purpose. **Link to tracking Issue:** #31918 **Testing:** This is a test added ahead of #31946, which refactors the hash-based decision but should not change its results. **Documentation:** n/a
open-telemetry · Apr 19, 2024 · 38c77fb · 38c77fb
1 parent 772cbc6
commit 38c77fb
Showing 1 changed file with 153 additions and 0 deletions.
diff --git a/processor/probabilisticsamplerprocessor/tracesprocessor_test.go b/processor/probabilisticsamplerprocessor/tracesprocessor_test.go
@@ -5,6 +5,7 @@ package probabilisticsamplerprocessor
 
 import (
 	"context"
+	"encoding/hex"
 	"math"
 	"math/rand"
 	"testing"
@@ -456,3 +457,155 @@ func assertSampledData(t *testing.T, sampled []ptrace.Traces, serviceName string
 	}
 	return
 }
+
+// mustParseTID generates TraceIDs from their hex encoding, for
+// testing probability sampling.
+func mustParseTID(in string) pcommon.TraceID {
+	b, err := hex.DecodeString(in)
+	if err != nil {
+		panic(err)
+	}
+	if len(b) != len(pcommon.TraceID{}) {
+		panic("incorrect size input")
+	}
+	return pcommon.TraceID(b)
+}
+
+// TestHashingFunction verifies 100 examples of the legacy hash-seed
+// based trace sampling decision.  This test is made prior to refactoring
+// the hash calculation to ensure legacy behavior does not change.
+func TestHashingFunction(t *testing.T) {
+	type expect50PctHashed struct {
+		seed    uint32
+		traceID string
+		sampled bool
+	}
+
+	var expect50PctData = []expect50PctHashed{
+		{653, "474a03c76d75951a4b4c537ced8f1122", true},
+		{563, "53a518291e91307e43cd8467bb06f986", true},
+		{142, "a56a02f843b9bc6ee0b13889249e90e6", true},
+		{904, "4e40762d3ee97a1c0932e4fa584f89a8", false},
+		{445, "5224507db93db513f0ea2a4b4e0578c8", true},
+		{38, "0c8717ced36216037af657e9d7f8b35b", true},
+		{561, "2a8aa76c18d08e1e8be935541f9318c7", false},
+		{757, "9e3d0f9481dc422cb613ea550897ae71", false},
+		{22, "66a66c516ac22054673e5da5e6492545", false},
+		{172, "84a1ce7bcea3e66194e72b4aa2694e31", true},
+		{552, "a811a7def34ca4b98d8e320afd115fad", false},
+		{546, "e3a345cc8dbb6f014bfa1edad3981820", true},
+		{315, "a71effb50e28d27cbdc9892f3765b8c2", false},
+		{510, "55ee665a3fa22f8ea1b744ce15a7339d", false},
+		{230, "7a5006be4d0ce7b542d59f83cd6f1c41", false},
+		{544, "825b8fb9cfd45867794f4cd8a5a699bd", false},
+		{790, "7629ecbea89398bfd9752a2f51c2c137", true},
+		{555, "de6cdfb44d69e211f886c57120d7bda0", true},
+		{147, "a8a5c3bb9205883fae17ead6675b2450", false},
+		{238, "937e6cb3332dbe87062fa3997f48f425", false},
+		{122, "5a357e150995e005847816c431ba502d", false},
+		{963, "20cb3dcebe2cf8abe6102f4a2e548245", false},
+		{141, "1b0afbd09abaaf7996cd26f8f6533795", false},
+		{666, "3ee60b013303bcfda06be89071b90bd1", true},
+		{305, "c90c7cf3471bbc3a804a8a831633705b", true},
+		{270, "18dda74dfca45a7b0261510f385fb4de", true},
+		{381, "600cf70c7bb4918e54aefd78c84f3996", true},
+		{35, "855f493c5b5b1e2fcbc9993f8061eac8", false},
+		{839, "89bc498feb21d969cf0eabf916aa621a", false},
+		{561, "0a0af00f63e098a39883705a423b0aa8", true},
+		{667, "0c38553d71f54dfc37155c22cc8bf243", false},
+		{603, "49493809d1a49ea879e6aba37afde958", true},
+		{92, "eb60d98b8f8fe22d8970f44f0e2b6bad", true},
+		{70, "19c386ee7a9f2d56ff9ab2e6374540af", false},
+		{567, "2a033c15405f1c7a311f653719ed47b7", false},
+		{936, "62dda24e4be24f5198e4d8dd4010c811", true},
+		{210, "bb134e26ee92e282e29cabdb1d00d333", true},
+		{835, "6c77db08bbded7bdd5c99c6e2fea41d2", false},
+		{864, "99f6a7e7b50845b4fb64b7c2ee49f53c", true},
+		{775, "e908cb91224bee8fd4b5f3632f65717f", true},
+		{687, "45a5ace7234d92d9983b4f3858bc0b8e", false},
+		{761, "8c8a25d232fd4d3a37a5f70ccb82d752", false},
+		{400, "54156d7434a894ef07f2a80dbf0f1138", true},
+		{741, "67e3bfb02b0526dbb79420468d7b83dd", false},
+		{871, "f6ea221283dcb42f89bfb15fa33398d2", false},
+		{244, "b663ca45004decf8123a19fb5d7f7115", true},
+		{885, "d0e299d54d6dc6469276fd4e48301d73", true},
+		{607, "03240c2748aa67a185909a9345d84aba", false},
+		{434, "b00de72ba67e6fe0ed661decac911f7e", true},
+		{889, "20fff68a7cc715b30e4e6d69d53e0f60", false},
+		{810, "6bf2bb105e594f6220803da5253551af", false},
+		{494, "54fbb1d3ebe3883b0a01bbf2c9a2bf3e", true},
+		{413, "a8a2ecba129d8537e360cf54de9d7460", false},
+		{215, "2df034262b775136f2a313fdcc09738a", true},
+		{557, "e3c1b943d9c1199d1108a69aa32a4587", false},
+		{662, "1975d5f5640bac1064d53c2c21e02aae", false},
+		{482, "6e4f16727dec3c09539b5f50d35d2c13", false},
+		{223, "63a088446ef0ed60a9cace4698ede026", false},
+		{261, "9b662cd6f67a4e3d1f904b4c5d4275b1", true},
+		{112, "a2db788dbadc402b8c466b93b8749a6c", true},
+		{6, "d6a68b47c66d1f94eed46b8ddc72faf4", false},
+		{575, "e8a83c42f4515568d0942ec4472c9d2c", true},
+		{568, "030e14c2954e3f08134b355f33414ba9", false},
+		{965, "022315846d42a38322d6fd26250444b3", true},
+		{512, "b3ba1ed226288dede87ac1f2ba88de2b", true},
+		{108, "c57d0dcf43d5b154ef04c7953c94cd12", true},
+		{248, "a835fe521d9cbfcfb724b603f87c7403", false},
+		{46, "eda867e6df95e74abefac336c7f4cd1a", false},
+		{879, "09e9e67a261ea3e00d817105b57ffd4e", false},
+		{853, "6a780cf250cb3d2b699394042e6723a8", false},
+		{639, "4c99d7f14c66b3123caf57980f8e2a31", false},
+		{111, "79dc8d7a54bc3e8ef513b9cd8d830564", true},
+		{135, "9c2e5d9d713e5219b0f9e5b884835e69", false},
+		{209, "3ccb300bf7b983229979e0c46db267b0", true},
+		{629, "0bb7b9da64da250c3934bb39130dc990", true},
+		{910, "b25713ca4cea377871eaa334bc2dd382", true},
+		{667, "69afc041003851cec60f41db97e005a9", true},
+		{449, "c844b5428abe0cf82eaf02566781870a", true},
+		{16, "2533c732bed8c1ba4721c25a1205f06c", false},
+		{936, "ecc770b4be885dfc8d6fa135bc2c93bb", true},
+		{595, "63b67cbb42de52e9916241ad94fcd5e8", true},
+		{83, "fc4998bc53ccd42a5b8e7c86a93d4c88", false},
+		{878, "59f0677dffe1a0a8c5895cb263e3a019", false},
+		{206, "eb897eff9e7c7363e063b340a0c6b315", true},
+		{710, "89e4c7e6af305be6cd139abcae953db5", true},
+		{650, "97563d45ee254231e1ace05fb746bcce", false},
+		{233, "3f580864f295ff13f179c3c907032ea9", true},
+		{836, "e9b78e03706265a6936bff2a41530104", false},
+		{568, "c458603ee921fa8711085c15b871b245", false},
+		{816, "4bbfffab5b5975c1b007ebc518bf416d", false},
+		{397, "61a1a65746287d78a431c6848ed1ffb3", false},
+		{847, "53eee02f4672a72e93369b2c2ecf36eb", false},
+		{354, "6ea23c3068a2c304488c8e67a072db97", false},
+		{961, "eed247645e510ded87bd9afcf1d3e237", false},
+		{799, "092af4ff2fdea5bb1c708b2169bdfd95", false},
+		{99, "497f02db51c898ac441aae18a8b7ced9", false},
+		{773, "988481445600bb91bbe23e3103034bcd", true},
+		{928, "f1813835ac0f456721ef3aac39c0269a", true},
+		{235, "1999920085682c007eb3a6984d2a7f05", true},
+		{460, "60c3b9a2dde734d71ba5cca7eb164bce", true},
+	}
+
+	// Note the test data above was created by essentially a
+	// one-off rewrite of the test body below, where instead of
+	// verifying it printed the expected results.
+	for _, tc := range expect50PctData {
+		sink := new(consumertest.TracesSink)
+		tsp, err := newTracesProcessor(context.Background(), processortest.NewNopCreateSettings(), &Config{
+			HashSeed:           tc.seed,
+			SamplingPercentage: 50,
+		}, sink)
+		if err != nil {
+			panic(err)
+		}
+		traces := ptrace.NewTraces()
+		span := traces.ResourceSpans().AppendEmpty().ScopeSpans().AppendEmpty().Spans().AppendEmpty()
+		span.SetTraceID(mustParseTID(tc.traceID))
+		err = tsp.ConsumeTraces(context.Background(), traces)
+		if err != nil {
+			panic(err)
+		}
+
+		wasSampled := len(sink.AllTraces()) == 1
+
+		require.Equal(t, tc.sampled, wasSampled)
+	}
+}