memgraph/tests/unit/durability.cpp
Teon Banek d7a9c5bab8 Extract TypedValue/DecodedValue conversion to higher component
Summary:
This is the first step in cutting the crazy dependencies of
communication module to the whole database. Includes have been
reorganized and conversion between DecodedValue and other Memgraph types
(TypedValue and PropertyValue) has been extracted to a higher level
component called `communication/conversion`. Encoder, like Decoder, now
relies only on DecodedValue. Hopefully the conversion operations will
not significantly slow down streaming Bolt data.

Additionally, Bolt ID is now wrapped in a class. Our storage model uses
*unsigned* int64, while Bolt expects *signed* int64. The implicit
conversions may lead to encode/decode errors, so the wrapper should
enforce some type safety to prevent such errors.

Reviewers: mferencevic, buda, msantl, mtomic

Reviewed By: mferencevic, mtomic

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D1453
2018-07-11 12:51:31 +02:00

873 lines
28 KiB
C++

#include <experimental/filesystem>
#include <experimental/optional>
#include <functional>
#include <random>
#include <thread>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "gflags/gflags.h"
#include "glog/logging.h"
#include "gtest/gtest.h"
#include "database/graph_db.hpp"
#include "database/graph_db_accessor.hpp"
#include "database/state_delta.hpp"
#include "durability/hashed_file_reader.hpp"
#include "durability/paths.hpp"
#include "durability/recovery.hpp"
#include "durability/snapshooter.hpp"
#include "durability/snapshot_decoder.hpp"
#include "durability/version.hpp"
#include "utils/string.hpp"
DECLARE_int32(wal_flush_interval_millis);
DECLARE_int32(wal_rotate_deltas_count);
DECLARE_string(durability_directory);
using namespace std::literals::chrono_literals;
namespace fs = std::experimental::filesystem;
// Helper class for performing random CRUD ops on a database.
class DbGenerator {
static constexpr int kLabelCount = 3;
static constexpr int kPropertyCount = 4;
static constexpr int kEdgeTypeCount = 2;
auto Label(int i) { return dba_.Label("label" + std::to_string(i)); }
auto Property(int i) { return dba_.Property("property" + std::to_string(i)); }
auto EdgeType(int i) {
return dba_.EdgeType("edge_type" + std::to_string(i));
}
public:
DbGenerator(database::GraphDbAccessor &dba) : dba_(dba) {}
void BuildIndex(int seq_number) {
dba_.BuildIndex(Label(seq_number % kLabelCount),
Property(seq_number % kPropertyCount));
}
EdgeAccessor RandomEdge(bool remove_from_ids = false) {
return dba_.FindEdge(RandomElement(edge_ids_, remove_from_ids), true);
}
VertexAccessor RandomVertex(bool remove_from_ids = false) {
return dba_.FindVertex(RandomElement(vertex_ids_, remove_from_ids), true);
}
VertexAccessor InsertVertex() {
auto vertex = dba_.InsertVertex();
vertex_ids_.emplace_back(vertex.gid());
return vertex;
}
void DetachRemoveVertex() {
auto vertex = RandomVertex(true);
dba_.RemoveVertex(vertex);
}
EdgeAccessor InsertEdge() {
auto from = RandomVertex();
auto to = RandomVertex();
auto edge = dba_.InsertEdge(from, to, EdgeType(RandomInt(kEdgeTypeCount)));
edge_ids_.emplace_back(edge.gid());
return edge;
}
EdgeAccessor InsertCycleEdge() {
auto vertex = RandomVertex();
auto edge =
dba_.InsertEdge(vertex, vertex, EdgeType(RandomInt(kEdgeTypeCount)));
edge_ids_.emplace_back(edge.gid());
return edge;
}
void RemoveEdge() {
auto edge = RandomEdge(true);
dba_.RemoveEdge(edge);
}
void SetVertexProperty() {
auto vertex = RandomVertex();
vertex.PropsSet(Property(RandomInt(kPropertyCount)), RandomValue());
}
void EraseVertexProperty() {
auto v = RandomVertex();
for (int i = 0; i < kPropertyCount; i++) v.PropsErase(Property(i));
}
void ClearVertexProperties() { RandomVertex().PropsClear(); }
void SetEdgeProperty() {
auto edge = RandomEdge();
edge.PropsSet(Property(RandomInt(kPropertyCount)), RandomValue());
}
void EraseEdgeProperty() {
auto e = RandomEdge();
for (int i = 0; i < kPropertyCount; i++) e.PropsErase(Property(i));
}
void ClearEdgeProperties() { RandomEdge().PropsClear(); }
void AddLabel() {
auto vertex = RandomVertex();
vertex.add_label(Label(RandomInt(kLabelCount)));
}
void ClearLabels() {
auto vertex = RandomVertex();
auto labels = vertex.labels();
for (auto label : labels) vertex.remove_label(label);
}
private:
database::GraphDbAccessor &dba_;
std::vector<int64_t> vertex_ids_;
std::vector<int64_t> edge_ids_;
std::mt19937 gen_{std::random_device{}()};
std::uniform_real_distribution<> rand_{0.0, 1.0};
int64_t RandomElement(std::vector<int64_t> &collection, bool remove = false) {
DCHECK(!collection.empty()) << "Random element from empty collection";
int64_t id = RandomInt(collection.size());
int64_t r_val = collection[id];
if (remove) {
collection[id] = collection.back();
collection.resize(collection.size() - 1);
}
return r_val;
}
int64_t RandomInt(int64_t upper_bound) { return rand_(gen_) * upper_bound; }
PropertyValue RandomValue() {
switch (RandomInt(3)) {
case 0:
return rand_(gen_); // Float
case 1:
return RandomInt(1000);
case 2:
return rand_(gen_) < 0.5;
default:
LOG(FATAL) << "Unsupported random value";
}
}
};
/** Checks if the given databases have the same contents (indices,
* vertices and edges). */
void CompareDbs(database::GraphDb &a, database::GraphDb &b) {
database::GraphDbAccessor dba_a(a);
database::GraphDbAccessor dba_b(b);
{
auto index_a = dba_a.IndexInfo();
auto index_b = dba_b.IndexInfo();
EXPECT_TRUE(
index_a.size() == index_b.size() &&
std::is_permutation(index_a.begin(), index_a.end(), index_b.begin()))
<< "Indexes not equal [" << utils::Join(index_a, ", ") << "] != ["
<< utils::Join(index_b, ", ");
}
auto is_permutation_props = [&dba_a, &dba_b](const auto &p1_id,
const auto &p2_id) {
std::vector<std::pair<std::string, query::TypedValue>> p1;
std::vector<std::pair<std::string, query::TypedValue>> p2;
for (auto x : p1_id) p1.push_back({dba_a.PropertyName(x.first), x.second});
for (auto x : p2_id) p2.push_back({dba_b.PropertyName(x.first), x.second});
// Don't use a binary predicate which depends on different value getters
// semantics for two containers because is_permutation might call the
// predicate with both arguments on the same container
return p1.size() == p2.size() &&
std::is_permutation(p1.begin(), p1.end(), p2.begin(),
[](const auto &p1, const auto &p2) {
return p1.first == p2.first &&
query::TypedValue::BoolEqual{}(
p1.second, p2.second);
});
};
{
int vertices_a_count = 0;
for (auto v_a : dba_a.Vertices(false)) {
vertices_a_count++;
auto v_b = dba_b.FindVertexOptional(v_a.gid(), false);
ASSERT_TRUE(v_b) << "Vertex not found, id: " << v_a.gid();
ASSERT_EQ(v_a.labels().size(), v_b->labels().size());
std::vector<std::string> v_a_labels;
std::vector<std::string> v_b_labels;
for (auto x : v_a.labels()) v_a_labels.push_back(dba_a.LabelName(x));
for (auto x : v_b->labels()) v_b_labels.push_back(dba_b.LabelName(x));
EXPECT_TRUE(std::is_permutation(v_a_labels.begin(), v_a_labels.end(),
v_b_labels.begin()));
EXPECT_TRUE(is_permutation_props(v_a.Properties(), v_b->Properties()));
}
auto vertices_b = dba_b.Vertices(false);
EXPECT_EQ(std::distance(vertices_b.begin(), vertices_b.end()),
vertices_a_count);
}
{
int edges_a_count = 0;
for (auto e_a : dba_a.Edges(false)) {
edges_a_count++;
auto e_b = dba_b.FindEdgeOptional(e_a.gid(), false);
ASSERT_TRUE(e_b);
ASSERT_TRUE(e_b) << "Edge not found, id: " << e_a.gid();
EXPECT_EQ(dba_a.EdgeTypeName(e_a.EdgeType()),
dba_b.EdgeTypeName(e_b->EdgeType()));
EXPECT_EQ(e_a.from().gid(), e_b->from().gid());
EXPECT_EQ(e_a.to().gid(), e_b->to().gid());
EXPECT_TRUE(is_permutation_props(e_a.Properties(), e_b->Properties()));
}
auto edges_b = dba_b.Edges(false);
EXPECT_EQ(std::distance(edges_b.begin(), edges_b.end()), edges_a_count);
}
}
std::vector<fs::path> DirFiles(fs::path dir) {
std::vector<fs::path> files;
if (fs::exists(dir))
for (auto &file : fs::directory_iterator(dir)) files.push_back(file.path());
return files;
}
fs::path GetLastFile(fs::path dir) {
std::vector<fs::path> files = DirFiles(dir);
CHECK(static_cast<int>(files.size()) > 0) << "No files in folder.";
return *std::max_element(files.begin(), files.end());
}
void MakeDb(durability::WriteAheadLog &wal, database::GraphDbAccessor &dba,
int scale, std::vector<int> indices = {}) {
DbGenerator generator{dba};
for (int i = 0; i < scale; i++) generator.InsertVertex();
for (int i = 0; i < scale * 2; i++) generator.InsertEdge();
for (int i = 0; i < scale / 2; i++) generator.InsertCycleEdge();
wal.Flush();
for (int i = 0; i < scale * 3; i++) {
generator.SetVertexProperty();
generator.SetEdgeProperty();
generator.AddLabel();
if (i % 500 == 0)
std::this_thread::sleep_for(std::chrono::milliseconds(30));
}
for (int i = 0; i < scale / 2; i++) {
generator.ClearLabels();
generator.EraseEdgeProperty();
generator.EraseVertexProperty();
generator.ClearEdgeProperties();
generator.ClearVertexProperties();
if (i % 500 == 0)
std::this_thread::sleep_for(std::chrono::milliseconds(30));
}
for (auto index : indices) generator.BuildIndex(index);
}
void MakeDb(database::GraphDb &db, int scale, std::vector<int> indices = {}) {
database::GraphDbAccessor dba{db};
MakeDb(db.wal(), dba, scale, indices);
dba.Commit();
}
class Durability : public ::testing::Test {
protected:
fs::path tmp_dir_ = fs::temp_directory_path() / "MG_test_unit_durability";
fs::path durability_dir_;
fs::path snapshot_dir_;
fs::path wal_dir_;
void CleanDurability() {
if (fs::exists(tmp_dir_)) fs::remove_all(tmp_dir_);
}
auto DbConfig() {
database::Config config;
config.durability_enabled = false;
config.durability_directory = durability_dir_;
config.snapshot_on_exit = false;
config.db_recover_on_startup = false;
return config;
}
void MakeSnapshot(database::GraphDb &db, int snapshot_max_retained = -1) {
database::GraphDbAccessor dba(db);
ASSERT_TRUE(durability::MakeSnapshot(db, dba, durability_dir_,
snapshot_max_retained));
}
void SetUp() override {
durability_dir_ = tmp_dir_ / utils::RandomString(24);
snapshot_dir_ = durability_dir_ / durability::kSnapshotDir;
wal_dir_ = durability_dir_ / durability::kWalDir;
FLAGS_wal_rotate_deltas_count = 1000;
FLAGS_durability_directory = "MG_test_unit_durability";
CleanDurability();
}
void TearDown() override { CleanDurability(); }
};
// Tests wal encoder to encode correctly non-CRUD deltas, and that all deltas
// are written in the correct order
TEST_F(Durability, WalEncoding) {
gid::Generator generator(0);
auto gid0 = generator.Next();
auto gid1 = generator.Next();
{
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
database::GraphDbAccessor dba(db);
auto v0 = dba.InsertVertex();
ASSERT_EQ(v0.gid(), gid0);
v0.add_label(dba.Label("l0"));
v0.PropsSet(dba.Property("p0"), 42);
auto v1 = dba.InsertVertex();
ASSERT_EQ(v1.gid(), gid1);
auto e0 = dba.InsertEdge(v0, v1, dba.EdgeType("et0"));
ASSERT_EQ(e0.gid(), gid0);
e0.PropsSet(dba.Property("p0"), std::vector<PropertyValue>{1, 2, 3});
dba.BuildIndex(dba.Label("l1"), dba.Property("p1"));
dba.Commit();
db.wal().Flush();
}
HashedFileReader reader;
ASSERT_EQ(DirFiles(wal_dir_).size(), 1);
ASSERT_TRUE(reader.Open(GetLastFile(wal_dir_)));
communication::bolt::Decoder<HashedFileReader> decoder{reader};
std::vector<database::StateDelta> deltas;
while (true) {
auto delta = database::StateDelta::Decode(reader, decoder);
if (delta) {
deltas.emplace_back(*delta);
} else {
break;
}
}
reader.Close();
ASSERT_EQ(deltas.size(), 11);
using Type = enum database::StateDelta::Type;
EXPECT_EQ(deltas[0].type, Type::TRANSACTION_BEGIN);
EXPECT_EQ(deltas[0].transaction_id, 1);
EXPECT_EQ(deltas[1].type, Type::CREATE_VERTEX);
EXPECT_EQ(deltas[1].transaction_id, 1);
EXPECT_EQ(deltas[2].type, Type::ADD_LABEL);
EXPECT_EQ(deltas[2].transaction_id, 1);
EXPECT_EQ(deltas[3].type, Type::SET_PROPERTY_VERTEX);
EXPECT_EQ(deltas[3].transaction_id, 1);
EXPECT_EQ(deltas[4].type, Type::CREATE_VERTEX);
EXPECT_EQ(deltas[4].transaction_id, 1);
EXPECT_EQ(deltas[5].type, Type::CREATE_EDGE);
EXPECT_EQ(deltas[5].transaction_id, 1);
EXPECT_EQ(deltas[6].type, Type::SET_PROPERTY_EDGE);
EXPECT_EQ(deltas[6].transaction_id, 1);
// The next two deltas are the BuildIndex internal transactions.
EXPECT_EQ(deltas[7].type, Type::TRANSACTION_BEGIN);
EXPECT_EQ(deltas[8].type, Type::BUILD_INDEX);
EXPECT_EQ(deltas[8].label_name, "l1");
EXPECT_EQ(deltas[8].property_name, "p1");
EXPECT_EQ(deltas[9].type, Type::TRANSACTION_COMMIT);
EXPECT_EQ(deltas[10].type, Type::TRANSACTION_COMMIT);
EXPECT_EQ(deltas[10].transaction_id, 1);
}
TEST_F(Durability, SnapshotEncoding) {
gid::Generator generator(0);
auto gid0 = generator.Next();
auto gid1 = generator.Next();
auto gid2 = generator.Next();
{
database::SingleNode db{DbConfig()};
database::GraphDbAccessor dba(db);
auto v0 = dba.InsertVertex();
ASSERT_EQ(v0.gid(), gid0);
v0.add_label(dba.Label("l0"));
v0.PropsSet(dba.Property("p0"), 42);
auto v1 = dba.InsertVertex();
ASSERT_EQ(v1.gid(), gid1);
v1.add_label(dba.Label("l0"));
v1.add_label(dba.Label("l1"));
auto v2 = dba.InsertVertex();
ASSERT_EQ(v2.gid(), gid2);
v2.PropsSet(dba.Property("p0"), true);
v2.PropsSet(dba.Property("p1"), "Johnny");
auto e0 = dba.InsertEdge(v0, v1, dba.EdgeType("et0"));
ASSERT_EQ(e0.gid(), gid0);
e0.PropsSet(dba.Property("p0"), std::vector<PropertyValue>{1, 2, 3});
auto e1 = dba.InsertEdge(v2, v1, dba.EdgeType("et1"));
ASSERT_EQ(e1.gid(), gid1);
dba.BuildIndex(dba.Label("l1"), dba.Property("p1"));
dba.Commit();
MakeSnapshot(db);
}
auto snapshot = GetLastFile(snapshot_dir_);
HashedFileReader buffer;
durability::SnapshotDecoder<HashedFileReader> decoder(buffer);
int64_t vertex_count, edge_count;
uint64_t hash;
ASSERT_TRUE(buffer.Open(snapshot));
ASSERT_TRUE(
durability::ReadSnapshotSummary(buffer, vertex_count, edge_count, hash));
ASSERT_EQ(vertex_count, 3);
ASSERT_EQ(edge_count, 2);
auto magic_number = durability::kMagicNumber;
buffer.Read(magic_number.data(), magic_number.size());
ASSERT_EQ(magic_number, durability::kMagicNumber);
communication::bolt::DecodedValue dv;
decoder.ReadValue(&dv);
ASSERT_EQ(dv.ValueInt(), durability::kVersion);
// Worker id
decoder.ReadValue(&dv);
ASSERT_EQ(dv.ValueInt(), 0);
// Number of generated vertex ids.
decoder.ReadValue(&dv);
ASSERT_TRUE(dv.IsInt());
// Number of generated edge ids.
decoder.ReadValue(&dv);
ASSERT_TRUE(dv.IsInt());
// Transaction ID.
decoder.ReadValue(&dv);
ASSERT_TRUE(dv.IsInt());
// Transactional snapshot.
decoder.ReadValue(&dv);
ASSERT_TRUE(dv.IsList());
// Label property indices.
decoder.ReadValue(&dv);
ASSERT_EQ(dv.ValueList().size(), 2);
EXPECT_EQ(dv.ValueList()[0].ValueString(), "l1");
EXPECT_EQ(dv.ValueList()[1].ValueString(), "p1");
std::map<gid::Gid, durability::DecodedSnapshotVertex> decoded_vertices;
// Decode vertices.
for (int i = 0; i < vertex_count; ++i) {
auto vertex = decoder.ReadSnapshotVertex();
ASSERT_NE(vertex, std::experimental::nullopt);
decoded_vertices.emplace(vertex->gid, *vertex);
}
ASSERT_EQ(decoded_vertices.size(), 3);
ASSERT_EQ(decoded_vertices[gid0].labels.size(), 1);
EXPECT_EQ(decoded_vertices[gid0].labels[0], "l0");
ASSERT_EQ(decoded_vertices[gid0].properties.size(), 1);
EXPECT_EQ(decoded_vertices[gid0].properties["p0"].ValueInt(), 42);
EXPECT_EQ(decoded_vertices[gid1].labels.size(), 2);
EXPECT_EQ(decoded_vertices[gid1].properties.size(), 0);
EXPECT_EQ(decoded_vertices[gid2].labels.size(), 0);
EXPECT_EQ(decoded_vertices[gid2].properties.size(), 2);
std::map<gid::Gid, communication::bolt::DecodedEdge> decoded_edges;
// Decode edges.
for (int i = 0; i < edge_count; ++i) {
decoder.ReadValue(&dv);
ASSERT_EQ(dv.type(), communication::bolt::DecodedValue::Type::Edge);
auto &edge = dv.ValueEdge();
decoded_edges.emplace(edge.id.AsUint(), edge);
// Read cypher_id.
decoder.ReadValue(&dv);
ASSERT_EQ(dv.type(), communication::bolt::DecodedValue::Type::Int);
}
EXPECT_EQ(decoded_edges.size(), 2);
EXPECT_EQ(decoded_edges[gid0].from.AsUint(), gid0);
EXPECT_EQ(decoded_edges[gid0].to.AsUint(), gid1);
EXPECT_EQ(decoded_edges[gid0].type, "et0");
EXPECT_EQ(decoded_edges[gid0].properties.size(), 1);
EXPECT_EQ(decoded_edges[gid1].from.AsUint(), gid2);
EXPECT_EQ(decoded_edges[gid1].to.AsUint(), gid1);
EXPECT_EQ(decoded_edges[gid1].type, "et1");
EXPECT_EQ(decoded_edges[gid1].properties.size(), 0);
// Vertex and edge counts are included in the hash. Re-read them to update
// the hash.
buffer.ReadType(vertex_count);
buffer.ReadType(edge_count);
buffer.Close();
EXPECT_EQ(buffer.hash(), hash);
}
TEST_F(Durability, SnapshotRecovery) {
database::SingleNode db{DbConfig()};
MakeDb(db, 300, {0, 1, 2});
MakeDb(db, 300);
MakeDb(db, 300, {3, 4});
MakeSnapshot(db);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
CompareDbs(db, recovered);
}
}
TEST_F(Durability, SnapshotNoVerticesIdRecovery) {
database::SingleNode db{DbConfig()};
MakeDb(db, 10);
// Erase all vertices, this should cause snapshot to not have any more
// vertices which should make it not change any id after snapshot recovery,
// but we still have to make sure that the id for generators is recovered
{
database::GraphDbAccessor dba(db);
for (auto vertex : dba.Vertices(false)) dba.RemoveVertex(vertex);
dba.Commit();
}
MakeSnapshot(db);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
EXPECT_EQ(db.storage().VertexGenerator().LocalCount(),
recovered.storage().VertexGenerator().LocalCount());
EXPECT_EQ(db.storage().EdgeGenerator().LocalCount(),
recovered.storage().EdgeGenerator().LocalCount());
}
}
TEST_F(Durability, SnapshotAndWalIdRecovery) {
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
MakeDb(db, 300);
MakeSnapshot(db);
MakeDb(db, 300);
db.wal().Flush();
ASSERT_EQ(DirFiles(snapshot_dir_).size(), 1);
EXPECT_GT(DirFiles(wal_dir_).size(), 1);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
EXPECT_EQ(db.storage().VertexGenerator().LocalCount(),
recovered.storage().VertexGenerator().LocalCount());
EXPECT_EQ(db.storage().EdgeGenerator().LocalCount(),
recovered.storage().EdgeGenerator().LocalCount());
}
}
TEST_F(Durability, OnlyWalIdRecovery) {
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
MakeDb(db, 300);
db.wal().Flush();
ASSERT_EQ(DirFiles(snapshot_dir_).size(), 0);
EXPECT_GT(DirFiles(wal_dir_).size(), 1);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
EXPECT_EQ(db.storage().VertexGenerator().LocalCount(),
recovered.storage().VertexGenerator().LocalCount());
EXPECT_EQ(db.storage().EdgeGenerator().LocalCount(),
recovered.storage().EdgeGenerator().LocalCount());
}
}
TEST_F(Durability, WalRecovery) {
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
MakeDb(db, 300, {0, 1, 2});
MakeDb(db, 300);
MakeDb(db, 300, {3, 4});
db.wal().Flush();
ASSERT_EQ(DirFiles(snapshot_dir_).size(), 0);
EXPECT_GT(DirFiles(wal_dir_).size(), 1);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
CompareDbs(db, recovered);
}
}
TEST_F(Durability, SnapshotAndWalRecovery) {
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
MakeDb(db, 300, {0, 1, 2});
MakeDb(db, 300);
MakeSnapshot(db);
MakeDb(db, 300, {3, 4});
MakeDb(db, 300);
MakeDb(db, 300, {5});
db.wal().Flush();
ASSERT_EQ(DirFiles(snapshot_dir_).size(), 1);
EXPECT_GT(DirFiles(wal_dir_).size(), 1);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
CompareDbs(db, recovered);
}
}
TEST_F(Durability, SnapshotAndWalRecoveryAfterComplexTxSituation) {
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
// The first transaction modifies and commits.
database::GraphDbAccessor dba_1{db};
MakeDb(db.wal(), dba_1, 100);
dba_1.Commit();
// The second transaction will commit after snapshot.
database::GraphDbAccessor dba_2{db};
MakeDb(db.wal(), dba_2, 100);
// The third transaction modifies and commits.
database::GraphDbAccessor dba_3{db};
MakeDb(db.wal(), dba_3, 100);
dba_3.Commit();
MakeSnapshot(db); // Snapshooter takes the fourth transaction.
dba_2.Commit();
// The fifth transaction starts and commits after snapshot.
database::GraphDbAccessor dba_5{db};
MakeDb(db.wal(), dba_5, 100);
dba_5.Commit();
// The sixth transaction will not commit at all.
database::GraphDbAccessor dba_6{db};
MakeDb(db.wal(), dba_6, 100);
auto VisibleVertexCount = [](database::GraphDb &db) {
database::GraphDbAccessor dba{db};
auto vertices = dba.Vertices(false);
return std::distance(vertices.begin(), vertices.end());
};
ASSERT_EQ(VisibleVertexCount(db), 400);
db.wal().Flush();
ASSERT_EQ(DirFiles(snapshot_dir_).size(), 1);
EXPECT_GT(DirFiles(wal_dir_).size(), 1);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
ASSERT_EQ(VisibleVertexCount(recovered), 400);
CompareDbs(db, recovered);
}
}
TEST_F(Durability, NoWalDuringRecovery) {
size_t wal_files_before;
{
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
MakeDb(db, 300, {0, 1, 2});
db.wal().Flush();
}
wal_files_before = DirFiles(wal_dir_).size();
ASSERT_GT(wal_files_before, 3);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
database::SingleNode recovered{recovered_config};
EXPECT_EQ(DirFiles(wal_dir_).size(), wal_files_before);
}
}
TEST_F(Durability, SnapshotRetention) {
database::SingleNode db{DbConfig()};
for (auto &pair : {std::pair<int, int>{5, 10}, {5, 3}, {7, -1}}) {
CleanDurability();
int count, retain;
std::tie(count, retain) = pair;
// Track the added snapshots to ensure the correct ones are pruned.
std::unordered_set<std::string> snapshots;
for (int i = 0; i < count; ++i) {
MakeSnapshot(db, retain);
auto latest = GetLastFile(snapshot_dir_);
snapshots.emplace(GetLastFile(snapshot_dir_));
// Ensures that the latest snapshot was not in the snapshots collection
// before. Thus ensures that it wasn't pruned.
EXPECT_EQ(snapshots.size(), i + 1);
}
EXPECT_EQ(DirFiles(snapshot_dir_).size(),
std::min(count, retain < 0 ? count : retain));
};
}
TEST_F(Durability, WalRetention) {
FLAGS_wal_rotate_deltas_count = 100;
{
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
MakeDb(db, 100);
MakeSnapshot(db);
MakeDb(db, 100);
EXPECT_EQ(DirFiles(snapshot_dir_).size(), 1);
db.wal().Flush();
// 1 current WAL file, plus retained ones
EXPECT_GT(DirFiles(wal_dir_).size(), 1);
MakeSnapshot(db);
db.wal().Flush();
}
// only 1 current WAL file
EXPECT_EQ(DirFiles(snapshot_dir_).size(), 2);
// There can only be one extra wal file (two total) because that file could
// have been written after the snapshot WAL cleanup
EXPECT_LE(DirFiles(wal_dir_).size(), 2);
}
TEST_F(Durability, SnapshotOnExit) {
{
auto config = DbConfig();
config.snapshot_on_exit = true;
database::SingleNode graph_db{config};
}
EXPECT_EQ(DirFiles(snapshot_dir_).size(), 1);
}
TEST_F(Durability, WorkerIdRecovery) {
auto config = DbConfig();
config.worker_id = 5;
database::SingleNode db{config};
MakeDb(db, 100);
MakeSnapshot(db);
EXPECT_EQ(DirFiles(snapshot_dir_).size(), 1);
// WorkerIds are equal and recovery should be sucessful
{
auto config = DbConfig();
config.worker_id = 5;
config.db_recover_on_startup = true;
database::SingleNode recovered{config};
EXPECT_EQ(recovered.WorkerId(), config.worker_id);
CompareDbs(db, recovered);
database::GraphDbAccessor dba(recovered);
EXPECT_NE(dba.VerticesCount(), 0);
EXPECT_NE(dba.EdgesCount(), 0);
}
// WorkerIds are not equal and recovery should fail
{
auto config = DbConfig();
config.worker_id = 10;
config.db_recover_on_startup = true;
database::SingleNode recovered{config};
EXPECT_NE(recovered.WorkerId(), db.WorkerId());
database::GraphDbAccessor dba(recovered);
EXPECT_EQ(dba.VerticesCount(), 0);
EXPECT_EQ(dba.EdgesCount(), 0);
}
}
TEST_F(Durability, SequentialRecovery) {
const int kNumWorkers = 6;
const int kNumVertices = 1000;
auto random_int = [](int upper_exclusive) {
static thread_local std::mt19937 pseudo_rand_gen{std::random_device{}()};
static thread_local std::uniform_int_distribution<int> rand_dist;
return rand_dist(pseudo_rand_gen) % upper_exclusive;
};
auto init_db = [](database::GraphDb &db) {
database::GraphDbAccessor dba{db};
for (int i = 0; i < kNumVertices; ++i) dba.InsertVertex(i);
dba.Commit();
};
auto run_updates = [&random_int](database::GraphDb &db,
std::atomic<bool> &keep_running) {
std::vector<std::thread> threads;
for (int i = 0; i < kNumWorkers; ++i) {
threads.emplace_back([&random_int, &db, &keep_running]() {
while (keep_running) {
database::GraphDbAccessor dba{db};
auto v = dba.FindVertex(random_int(kNumVertices), false);
try {
v.PropsSet(dba.Property("prop"), random_int(100));
} catch (utils::LockTimeoutException &) {
} catch (mvcc::SerializationError &) {
}
dba.InsertVertex();
dba.Commit();
}
});
}
return threads;
};
auto make_updates = [&run_updates, this](database::GraphDb &db,
bool snapshot_during,
bool snapshot_after) {
std::atomic<bool> keep_running{true};
auto update_theads = run_updates(db, keep_running);
std::this_thread::sleep_for(25ms);
if (snapshot_during) {
MakeSnapshot(db);
}
std::this_thread::sleep_for(25ms);
keep_running = false;
for (auto &t : update_theads) t.join();
if (snapshot_after) {
MakeSnapshot(db);
}
db.wal().Flush();
};
const std::vector<std::pair<bool, bool>> combinations{{0, 0}, {1, 0}, {0, 1}};
for (auto &combo : combinations) {
CleanDurability();
auto config = DbConfig();
config.durability_enabled = true;
database::SingleNode db{config};
init_db(db);
make_updates(db, combo.first, combo.second);
{
auto recovered_config = DbConfig();
recovered_config.db_recover_on_startup = true;
recovered_config.durability_enabled = true;
database::SingleNode recovered{recovered_config};
CompareDbs(db, recovered);
{
for (auto &combo2 : combinations) {
make_updates(recovered, combo2.first, combo2.second);
database::SingleNode recovered_2{recovered_config};
CompareDbs(recovered, recovered_2);
}
}
}
}
}