memgraph/tests/stress/long_running.cpp
Matej Ferencevic 84a6ab75cb Fix race condition in long running stress test
Summary:
The long running stress test had a subtle race condition which caused the test
to fail with an error message like "Runner X edges creation failed because of:
Can't serialize due to concurrent operations.". This situation was caused
because some workers could complete their initialization (initial vertex and
edge creation) before other workers. The workers that completed their
initialization would then proceed to execute the test. In the test they could
execute queries that make global updates on the graph that could interfere with
the concurrently running initialization queries of other workers.

This diff makes the runners wait until all initialization queries are fully
executed before they execute global operations on the graph.

Reviewers: teon.banek

Reviewed By: teon.banek

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D2647
2020-01-29 10:19:53 +01:00

475 lines
16 KiB
C++

#include <atomic>
#include <fstream>
#include <random>
#include <set>
#include <thread>
#include <fmt/format.h>
#include <gflags/gflags.h>
#include <glog/logging.h>
#include "communication/bolt/client.hpp"
#include "io/network/endpoint.hpp"
#include "utils/exceptions.hpp"
#include "utils/timer.hpp"
using EndpointT = io::network::Endpoint;
using ClientContextT = communication::ClientContext;
using ClientT = communication::bolt::Client;
using ValueT = communication::bolt::Value;
using QueryDataT = communication::bolt::QueryData;
using ExceptionT = communication::bolt::ClientQueryException;
DEFINE_string(address, "127.0.0.1", "Server address");
DEFINE_int32(port, 7687, "Server port");
DEFINE_string(username, "", "Username for the database");
DEFINE_string(password, "", "Password for the database");
DEFINE_bool(use_ssl, false, "Set to true to connect with SSL to the server.");
DEFINE_int32(vertex_count, 0,
"The average number of vertices in the graph per worker");
DEFINE_int32(edge_count, 0,
"The average number of edges in the graph per worker");
DEFINE_int32(prop_count, 5, "The max number of properties on a node");
DEFINE_uint64(max_queries, 1 << 30, "Maximum number of queries to execute");
DEFINE_int32(max_time, 1, "Maximum execution time in minutes");
DEFINE_int32(verify, 0, "Interval (seconds) between checking local info");
DEFINE_int32(worker_count, 1,
"The number of workers that operate on the graph independently");
DEFINE_bool(global_queries, true,
"If queries that modifiy globally should be executed sometimes");
DEFINE_string(stats_file, "", "File into which to write statistics.");
/**
* Encapsulates a Graph and a Bolt session and provides CRUD op functions.
* Also defines a run-loop for a generic exectutor, and a graph state
* verification function.
*/
class GraphSession {
public:
GraphSession(int id, std::atomic<uint64_t> *init_complete)
: id_(id),
init_complete_(init_complete),
indexed_label_(fmt::format("indexed_label{}", id)),
generator_{std::random_device{}()} {
for (int i = 0; i < FLAGS_prop_count; ++i) {
auto label = fmt::format("label{}", i);
labels_.insert(label);
labels_vertices_.insert({label, {}});
}
EndpointT endpoint(FLAGS_address, FLAGS_port);
client_ = std::make_unique<ClientT>(&context_);
client_->Connect(endpoint, FLAGS_username, FLAGS_password);
}
private:
uint64_t id_;
std::atomic<uint64_t> *init_complete_;
ClientContextT context_{FLAGS_use_ssl};
std::unique_ptr<ClientT> client_;
uint64_t vertex_id_{0};
uint64_t edge_id_{0};
std::set<uint64_t> vertices_;
std::set<uint64_t> edges_;
std::string indexed_label_;
std::set<std::string> labels_;
std::map<std::string, std::set<uint64_t>> labels_vertices_;
uint64_t executed_queries_{0};
std::map<std::string, uint64_t> query_failures_;
std::mt19937 generator_;
utils::Timer timer_;
private:
double GetRandom() { return std::generate_canonical<double, 10>(generator_); }
bool Bernoulli(double p) { return GetRandom() < p; }
uint64_t RandomElement(std::set<uint64_t> &data) {
uint64_t min = *data.begin(), max = *data.rbegin();
uint64_t val = std::floor(GetRandom() * (max - min) + min);
auto it = data.lower_bound(val);
return *it;
}
std::string RandomElement(std::set<std::string> &data) {
uint64_t pos = std::floor(GetRandom() * data.size());
auto it = data.begin();
std::advance(it, pos);
return *it;
}
void AddQueryFailure(const std::string &what) {
auto it = query_failures_.find(what);
if (it != query_failures_.end()) {
++it->second;
} else {
query_failures_.insert(std::make_pair(what, 1));
}
}
QueryDataT ExecuteWithoutCatch(const std::string &query) {
DLOG(INFO) << "Runner " << id_ << " executing query: " << query;
executed_queries_ += 1;
return client_->Execute(query, {});
}
QueryDataT Execute(const std::string &query) {
try {
return ExecuteWithoutCatch(query);
} catch (const ExceptionT &e) {
AddQueryFailure(e.what());
return QueryDataT();
}
}
void CreateVertices(uint64_t vertices_count) {
if (vertices_count == 0) return;
QueryDataT ret;
try {
ret = ExecuteWithoutCatch(fmt::format(
"UNWIND RANGE({}, {}) AS r CREATE (n:{} {{id: r}}) RETURN count(n)",
vertex_id_, vertex_id_ + vertices_count - 1, indexed_label_));
} catch (const ExceptionT &e) {
LOG(FATAL) << "Runner " << id_
<< " vertices creation failed because of: " << e.what();
}
CHECK(ret.records.size())
<< "Runner " << id_
<< " the vertices creation query should have returned a row!";
CHECK(ret.records[0][0].ValueInt() == vertices_count)
<< "Runner " << id_ << " created " << ret.records[0][0].ValueInt()
<< " vertices instead of " << vertices_count << "!";
for (uint64_t i = 0; i < vertices_count; ++i) {
CHECK(vertices_.insert(vertex_id_ + i).second)
<< "Runner " << id_ << " vertex with ID " << vertex_id_ + i
<< " shouldn't exist!";
}
vertex_id_ += vertices_count;
}
void RemoveVertex() {
auto vertex_id = RandomElement(vertices_);
auto ret = Execute(fmt::format(
"MATCH (n:{} {{id: {}}}) OPTIONAL MATCH (n)-[r]-() "
"WITH n, n.id as n_id, labels(n) as labels_n, collect(r.id) as r_ids "
"DETACH DELETE n RETURN n_id, labels_n, r_ids",
indexed_label_, vertex_id));
if (ret.records.size() > 0) {
std::set<uint64_t> processed_vertices;
auto &record = ret.records[0];
// remove vertex but note there could be duplicates
auto n_id = record[0].ValueInt();
if (processed_vertices.insert(n_id).second) {
CHECK(vertices_.erase(n_id)) << "Runner " << id_ << " vertex with ID "
<< n_id << " should exist!";
for (auto &label : record[1].ValueList()) {
if (label.ValueString() == indexed_label_) {
continue;
}
labels_vertices_[label.ValueString()].erase(n_id);
}
}
// remove edge
auto &edges = record[2];
for (auto &edge : edges.ValueList()) {
if (edge.type() == ValueT::Type::Int) {
CHECK(edges_.erase(edge.ValueInt()))
<< "Runner " << id_ << " edge with ID " << edge.ValueInt()
<< " should exist!";
}
}
}
}
void CreateEdges(uint64_t edges_count) {
if (edges_count == 0) return;
auto edges_per_node = (double)edges_count / vertices_.size();
CHECK(std::abs(edges_per_node - (int64_t)edges_per_node) < 0.0001)
<< "Runner " << id_ << " edges per node not a whole number!";
QueryDataT ret;
try {
ret = ExecuteWithoutCatch(fmt::format(
"MATCH (a:{0}) WITH a "
"UNWIND range(0, {1}) AS i WITH a, tointeger(rand() * {2}) AS id "
"MATCH (b:{0} {{id: id}}) WITH a, b "
"CREATE (a)-[e:EdgeType {{id: counter(\"edge\", {3})}}]->(b) "
"RETURN count(e)",
indexed_label_, (int64_t)edges_per_node - 1, vertices_.size(),
edge_id_));
} catch (const ExceptionT &e) {
LOG(FATAL) << "Runner " << id_
<< " edges creation failed because of: " << e.what();
}
CHECK(ret.records.size())
<< "Runner " << id_
<< " the edges creation query should have returned a row!";
uint64_t count = ret.records[0][0].ValueInt();
for (uint64_t i = 0; i < count; ++i) {
CHECK(edges_.insert(edge_id_ + i).second)
<< "Runner " << id_ << " edge with ID " << edge_id_ + i
<< " shouldn't exist!";
}
edge_id_ += count;
}
void CreateEdge() {
auto ret = Execute(
fmt::format("MATCH (from:{} {{id: {}}}), (to:{} {{id: {}}}) "
"CREATE (from)-[e:EdgeType {{id: {}}}]->(to) RETURN 1",
indexed_label_, RandomElement(vertices_), indexed_label_,
RandomElement(vertices_), edge_id_));
if (ret.records.size() > 0) {
CHECK(edges_.insert(edge_id_).second)
<< "Runner " << id_ << " edge with ID " << edge_id_
<< " shouldn't exist!";
++edge_id_;
}
}
void AddLabel() {
auto vertex_id = RandomElement(vertices_);
auto label = RandomElement(labels_);
// add a label on a vertex that didn't have that label
// yet (we need that for book-keeping)
auto ret = Execute(
fmt::format("MATCH (v:{} {{id: {}}}) WHERE not v:{} SET v:{} RETURN 1",
indexed_label_, vertex_id, label, label));
if (ret.records.size() > 0) {
labels_vertices_[label].insert(vertex_id);
}
}
void UpdateGlobalVertices() {
uint64_t vertex_id = *vertices_.rbegin();
uint64_t lo = std::floor(GetRandom() * vertex_id);
uint64_t hi = std::floor(lo + vertex_id * 0.01);
uint64_t num = std::floor(GetRandom() * (1 << 30));
Execute(
fmt::format("MATCH (n) WHERE n.id > {} AND n.id < {} SET n.value = {}",
lo, hi, num));
}
void UpdateGlobalEdges() {
uint64_t vertex_id = *vertices_.rbegin();
uint64_t lo = std::floor(GetRandom() * vertex_id);
uint64_t hi = std::floor(lo + vertex_id * 0.01);
uint64_t num = std::floor(GetRandom() * (1 << 30));
Execute(fmt::format(
"MATCH ()-[e]->() WHERE e.id > {} AND e.id < {} SET e.value = {}", lo,
hi, num));
}
/** Checks if the local info corresponds to DB state */
void VerifyGraph() {
// helper lambda for set verification
auto test_set = [this](const auto &query, const auto &container,
const auto &what) {
QueryDataT ret;
try {
ret = ExecuteWithoutCatch(query);
} catch (const ExceptionT &e) {
LOG(FATAL) << "Runner " << id_ << " couldn't execute " << what
<< " ID retrieval because of: " << e.what();
}
CHECK(ret.records.size() == container.size())
<< "Runner " << id_ << " expected " << container.size() << " " << what
<< ", found " << ret.records.size() << "!";
for (size_t i = 0; i < ret.records.size(); ++i) {
CHECK(ret.records[i].size() == 1)
<< "Runner " << id_ << " received an invalid ID row for " << what
<< "!";
auto id = ret.records[i][0].ValueInt();
CHECK(container.find(id) != container.end())
<< "Runner " << id_ << " couldn't find ID " << id << " for " << what
<< "! Examined " << i << " items out of " << ret.records.size()
<< " items!";
}
};
test_set(fmt::format("MATCH (n:{}) RETURN n.id", indexed_label_), vertices_,
"vertices");
test_set(
fmt::format("MATCH (:{0})-[r]->(:{0}) RETURN r.id", indexed_label_),
edges_, "edges");
for (auto &item : labels_vertices_) {
test_set(fmt::format("MATCH (n:{}:{}) RETURN n.id", indexed_label_,
item.first),
item.second,
fmt::format("vertices with label '{}'", item.first));
}
// generate report
std::ostringstream report;
report << fmt::format("Runner {} graph verification success:", id_)
<< std::endl
<< fmt::format("\tExecuted {} queries in {:.2f} seconds",
executed_queries_, timer_.Elapsed().count())
<< std::endl
<< fmt::format("\tGraph has {} vertices and {} edges",
vertices_.size(), edges_.size())
<< std::endl;
for (auto &label : labels_) {
report << fmt::format("\tVertices with label '{}': {}", label,
labels_vertices_[label].size())
<< std::endl;
}
if (query_failures_.size() > 0) {
report << "\tQuery failed (reason: count)" << std::endl;
for (auto &item : query_failures_) {
report << fmt::format("\t\t'{}': {}", item.first, item.second)
<< std::endl;
}
}
LOG(INFO) << report.str();
}
public:
void Run() {
// initial vertex creation
CreateVertices(FLAGS_vertex_count);
// initial edge creation
CreateEdges(FLAGS_edge_count);
VerifyGraph();
double last_verify = timer_.Elapsed().count();
// notify that we completed our initialization
init_complete_->fetch_add(-1, std::memory_order_acq_rel);
// run rest
while (executed_queries_ < FLAGS_max_queries &&
timer_.Elapsed().count() / 60.0 < FLAGS_max_time) {
if (FLAGS_verify > 0 &&
timer_.Elapsed().count() - last_verify > FLAGS_verify) {
VerifyGraph();
last_verify = timer_.Elapsed().count();
}
double ratio_e = (double)edges_.size() / (double)FLAGS_edge_count;
double ratio_v = (double)vertices_.size() / (double)FLAGS_vertex_count;
// try to edit vertices globally if all workers completed their
// initialization
if (FLAGS_global_queries &&
init_complete_->load(std::memory_order_acquire) == 0) {
if (Bernoulli(0.01)) {
UpdateGlobalVertices();
}
// try to edit edges globally
if (Bernoulli(0.01)) {
UpdateGlobalEdges();
}
}
// if we're missing edges (due to vertex detach delete), add some!
if (Bernoulli(ratio_e < 0.9)) {
CreateEdge();
continue;
}
// if we are near vertex balance, we can also do updates
// instad of update / deletes
if (std::fabs(1.0 - ratio_v) < 0.5 && Bernoulli(0.5)) {
AddLabel();
continue;
}
if (Bernoulli(ratio_v / 2.0)) {
RemoveVertex();
} else {
CreateVertices(1);
}
}
// final verification
VerifyGraph();
}
uint64_t GetExecutedQueries() { return executed_queries_; }
uint64_t GetFailedQueries() {
uint64_t failed = 0;
for (const auto &item : query_failures_) {
failed += item.second;
}
return failed;
}
};
int main(int argc, char **argv) {
gflags::ParseCommandLineFlags(&argc, &argv, true);
google::InitGoogleLogging(argv[0]);
communication::Init();
CHECK(FLAGS_vertex_count > 0) << "Vertex count must be greater than 0!";
CHECK(FLAGS_edge_count > 0) << "Edge count must be greater than 0!";
LOG(INFO) << "Starting Memgraph long running test";
// create client
EndpointT endpoint(FLAGS_address, FLAGS_port);
ClientContextT context(FLAGS_use_ssl);
ClientT client(&context);
client.Connect(endpoint, FLAGS_username, FLAGS_password);
// cleanup and create indexes
client.Execute("MATCH (n) DETACH DELETE n", {});
for (int i = 0; i < FLAGS_worker_count; ++i) {
client.Execute(fmt::format("CREATE INDEX ON :indexed_label{}", i), {});
client.Execute(fmt::format("CREATE INDEX ON :indexed_label{}(id)", i), {});
}
// close client
client.Close();
// sessions
std::vector<GraphSession> sessions;
std::atomic<uint64_t> init_complete(FLAGS_worker_count);
sessions.reserve(FLAGS_worker_count);
for (int i = 0; i < FLAGS_worker_count; ++i) {
sessions.emplace_back(i, &init_complete);
}
// workers
std::vector<std::thread> threads;
for (int i = 0; i < FLAGS_worker_count; ++i) {
threads.push_back(std::thread([&, i]() { sessions[i].Run(); }));
}
for (int i = 0; i < FLAGS_worker_count; ++i) {
threads[i].join();
}
if (FLAGS_stats_file != "") {
uint64_t executed = 0, failed = 0;
for (int i = 0; i < FLAGS_worker_count; ++i) {
executed += sessions[i].GetExecutedQueries();
failed += sessions[i].GetFailedQueries();
}
std::ofstream stream(FLAGS_stats_file);
stream << executed << std::endl << failed << std::endl;
LOG(INFO) << fmt::format("Written statistics to file: {}",
FLAGS_stats_file);
}
LOG(INFO) << "All query runners done";
return 0;
}