Mooncake/mooncake-store/tests/allocation_strategy_test.cpp

756 lines
31 KiB
C++

#include "allocation_strategy.h"
#include <gtest/gtest.h>
#include <algorithm>
#include <array>
#include <cmath>
#include <iomanip>
#include <memory>
#include <numeric>
#include <set>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "allocator.h"
#include "types.h"
namespace mooncake {
// Size units for better readability
static constexpr size_t MiB = 1024 * 1024;
// Strategy types for parameterized tests
const auto kStrategyTypes = ::testing::Values(
AllocationStrategyType::RANDOM, AllocationStrategyType::FREE_RATIO_FIRST);
const auto kAllocatorTypes = ::testing::Values(BufferAllocatorType::CACHELIB,
BufferAllocatorType::OFFSET);
// Base class for non-parameterized tests
class AllocationStrategyTest : public ::testing::Test {
protected:
void SetUp() override {
strategy_ = std::make_unique<RandomAllocationStrategy>();
}
std::unique_ptr<RandomAllocationStrategy> strategy_;
};
// Parameterized test class for strategy and allocator type variations
class AllocationStrategyParameterizedTest
: public ::testing::TestWithParam<
std::tuple<AllocationStrategyType, BufferAllocatorType>> {
protected:
void SetUp() override {
auto [strategy_type, allocator_type] = GetParam();
strategy_ = CreateAllocationStrategy(strategy_type);
allocator_type_ = allocator_type;
}
// Helper function to create a BufferAllocator for testing
// Using segment_name as transport_endpoint for simplicity
std::shared_ptr<BufferAllocatorBase> CreateTestAllocator(
const std::string& segment_name, size_t base_offset,
size_t size = 64 * MiB) {
const size_t base = 0x100000000ULL + base_offset; // 4GB + offset
switch (allocator_type_) {
case BufferAllocatorType::CACHELIB:
return std::make_shared<CachelibBufferAllocator>(
segment_name, base, size, segment_name);
case BufferAllocatorType::OFFSET:
return std::make_shared<OffsetBufferAllocator>(
segment_name, base, size, segment_name);
default:
throw std::invalid_argument("Invalid allocator type");
}
}
BufferAllocatorType allocator_type_;
std::shared_ptr<AllocationStrategy> strategy_;
};
// Instantiate parameterized tests for all strategy and allocator combinations
INSTANTIATE_TEST_SUITE_P(
AllCombinations, AllocationStrategyParameterizedTest,
::testing::Combine(kStrategyTypes, kAllocatorTypes),
[](const ::testing::TestParamInfo<
std::tuple<AllocationStrategyType, BufferAllocatorType>>& info) {
AllocationStrategyType strategy_type = std::get<0>(info.param);
BufferAllocatorType allocator_type = std::get<1>(info.param);
std::string strategy_str;
switch (strategy_type) {
case AllocationStrategyType::RANDOM:
strategy_str = "Random";
break;
case AllocationStrategyType::FREE_RATIO_FIRST:
strategy_str = "FreeRatioFirst";
break;
default:
strategy_str = "Unknown";
}
std::string allocator_str =
(allocator_type == BufferAllocatorType::CACHELIB) ? "Cachelib"
: "Offset";
return strategy_str + "_" + allocator_str;
});
// Test basic functionality with empty allocators map (non-parameterized)
TEST_F(AllocationStrategyTest, EmptyAllocatorsMap) {
AllocatorManager allocator_manager;
size_t slice_length = 100;
auto result =
strategy_->Allocate(allocator_manager, slice_length, 1, {}, {});
EXPECT_FALSE(result.has_value());
EXPECT_EQ(result.error(), ErrorCode::NO_AVAILABLE_HANDLE);
}
// Test preferred segment behavior with empty allocators (non-parameterized)
TEST_F(AllocationStrategyTest, PreferredSegmentWithEmptyAllocators) {
AllocatorManager allocator_manager;
size_t slice_length = 100;
std::vector<std::string> preferred_segments = {"preferred_segment"};
auto result = strategy_->Allocate(allocator_manager, slice_length, 1,
preferred_segments, {});
EXPECT_FALSE(result.has_value());
EXPECT_EQ(result.error(), ErrorCode::NO_AVAILABLE_HANDLE);
}
// Test preferred segment allocation when available
TEST_P(AllocationStrategyParameterizedTest, PreferredSegmentAllocation) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("preferred", 0x10000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("preferred", allocator2);
size_t slice_length = 1024;
std::vector<std::string> preferred_segments = {"preferred"};
auto result = strategy_->Allocate(allocator_manager, slice_length, 1,
preferred_segments, {});
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 1);
ASSERT_FALSE(result.value().empty());
const auto& replica = result.value()[0];
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
EXPECT_EQ(mem_desc.buffer_descriptor.transport_endpoint_, "preferred");
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
// Test fallback to random allocation when preferred segment doesn't exist
TEST_P(AllocationStrategyParameterizedTest, PreferredSegmentNotFound) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("segment2", 0x10000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("segment2", allocator2);
size_t slice_length = 1024;
std::vector<std::string> preferred_segments = {"nonexistent"};
auto result = strategy_->Allocate(allocator_manager, slice_length, 1,
preferred_segments, {});
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 1);
const auto& replica = result.value()[0];
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
std::string segment_ep = mem_desc.buffer_descriptor.transport_endpoint_;
EXPECT_TRUE(segment_ep == "segment1" || segment_ep == "segment2");
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
// Test single slice allocation
TEST_P(AllocationStrategyParameterizedTest, SingleSliceAllocation) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("segment2", 0x10000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("segment2", allocator2);
size_t slice_length = 1024;
auto result =
strategy_->Allocate(allocator_manager, slice_length, 1, {}, {});
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 1);
const auto& replica = result.value()[0];
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
// Test multiple replicas allocation
TEST_P(AllocationStrategyParameterizedTest, MultipleReplicasAllocation) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("segment2", 0x10000000ULL);
auto allocator3 = CreateTestAllocator("segment3", 0x20000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("segment2", allocator2);
allocator_manager.addAllocator("segment3", allocator3);
size_t slice_length = 1024;
auto result = strategy_->Allocate(allocator_manager, slice_length, 3, {},
{}); // Request 3 replicas
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 3);
// Check each replica has the correct slice size
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
// Check that replicas are on different segments
std::set<std::string> used_segments;
for (const auto& replica : result.value()) {
auto segment_names = replica.get_segment_names();
for (const auto& name_ptr : segment_names) {
if (name_ptr) {
used_segments.insert(*name_ptr);
}
}
}
}
// Test allocation when preferred segment has insufficient space
TEST_P(AllocationStrategyParameterizedTest, PreferredSegmentInsufficientSpace) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("preferred", 0x10000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("preferred", allocator2);
// First, fill up the preferred allocator
std::vector<std::string> preferred_segments = {"preferred"};
// Store the results of the allocations to avoid deallocation of the buffers
// before the test is done
std::vector<std::vector<Replica>> results;
// Allocate multiple times to fill up the preferred allocator
for (int i = 0; i < 4; ++i) {
size_t large_slice = 15 * 1024 * 1024; // 15MB
auto large_result = strategy_->Allocate(allocator_manager, large_slice,
1, preferred_segments, {});
ASSERT_TRUE(large_result.has_value());
auto last_desc = large_result.value()[0].get_descriptor();
ASSERT_TRUE(last_desc.is_memory_replica());
EXPECT_EQ(last_desc.get_memory_descriptor()
.buffer_descriptor.transport_endpoint_,
"preferred");
results.emplace_back(std::move(large_result.value()));
}
// Now try to allocate more than remaining space in preferred segment
size_t small_slice = 5 * 1024 * 1024; // 5MB
auto result = strategy_->Allocate(allocator_manager, small_slice, 1,
preferred_segments, {});
ASSERT_TRUE(result.has_value());
auto small_desc = result.value()[0].get_descriptor();
ASSERT_TRUE(small_desc.is_memory_replica());
const auto& mem_desc = small_desc.get_memory_descriptor();
EXPECT_EQ(mem_desc.buffer_descriptor.transport_endpoint_,
"segment1"); // Falls back to other segment
EXPECT_EQ(mem_desc.buffer_descriptor.size_, small_slice);
}
// Test allocation when all allocators are full
TEST_P(AllocationStrategyParameterizedTest, AllAllocatorsFull) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("segment2", 0x10000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("segment2", allocator2);
// Fill up both allocators
size_t large_slice = 15 * 1024 * 1024; // 15MB
// Store the results of the allocations to avoid deallocation of the buffers
// before the test is done
std::vector<std::vector<Replica>> results;
// Allocate 8 times to use 120MB total
for (int i = 0; i < 8; ++i) {
auto result =
strategy_->Allocate(allocator_manager, large_slice, 1, {}, {});
ASSERT_TRUE(result.has_value());
results.emplace_back(std::move(result.value()));
}
// Try to allocate more than remaining space
size_t impossible_slice = 5 * 1024 * 1024; // 5MB (more than remaining)
auto result =
strategy_->Allocate(allocator_manager, impossible_slice, 1, {}, {});
EXPECT_FALSE(result.has_value());
EXPECT_EQ(result.error(), ErrorCode::NO_AVAILABLE_HANDLE);
}
// Test allocation with zero size
TEST_P(AllocationStrategyParameterizedTest, ZeroSizeAllocation) {
auto allocator = CreateTestAllocator("segment1", 0);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator);
size_t zero_slice = 0;
auto result = strategy_->Allocate(allocator_manager, zero_slice, 1, {}, {});
EXPECT_FALSE(result.has_value());
EXPECT_EQ(result.error(), ErrorCode::INVALID_PARAMS);
}
// Test allocation with very large size
TEST_P(AllocationStrategyParameterizedTest, VeryLargeSizeAllocation) {
auto allocator = CreateTestAllocator("segment1", 0);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator);
size_t huge_slice = 100 * 1024 * 1024; // 100MB (larger than 64MB capacity)
auto result = strategy_->Allocate(allocator_manager, huge_slice, 1, {}, {});
EXPECT_FALSE(result.has_value());
EXPECT_EQ(result.error(), ErrorCode::NO_AVAILABLE_HANDLE);
}
// Test zero slice length (already covered by ZeroSizeAllocation test)
// Test invalid replication count
TEST_F(AllocationStrategyTest, InvalidReplicationCount) {
auto allocator = std::make_shared<OffsetBufferAllocator>(
"segment1", 0x100000000ULL, 64 * MiB, "segment1");
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator);
size_t slice_length = 1024;
auto result = strategy_->Allocate(allocator_manager, slice_length, 0, {},
{}); // Invalid: 0 replicas
EXPECT_FALSE(result.has_value());
EXPECT_EQ(result.error(), ErrorCode::INVALID_PARAMS);
}
// Test best-effort behavior when insufficient allocators for requested replica
// count
TEST_F(AllocationStrategyTest, InsufficientAllocatorsForReplicas) {
auto allocator1 = std::make_shared<OffsetBufferAllocator>(
"segment1", 0x100000000ULL, 64 * MiB, "segment1");
auto allocator2 = std::make_shared<OffsetBufferAllocator>(
"segment2", 0x100000000ULL + 0x10000000ULL, 64 * MiB, "segment2");
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("segment2", allocator2);
size_t slice_length = 1024;
auto result = strategy_->Allocate(
allocator_manager, slice_length, 5, {},
{}); // Request 5 replicas, but only 2 segments available
// With best-effort semantics, should succeed with available replicas
EXPECT_TRUE(result.has_value());
// Should get 2 replicas (limited by number of segments)
EXPECT_EQ(2u, result.value().size());
// Verify each replica has the expected slice structure
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024u);
}
// Verify replicas are on different segments
std::unordered_set<std::string> segment_names;
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
const auto& mem_desc = descriptor.get_memory_descriptor();
segment_names.insert(mem_desc.buffer_descriptor.transport_endpoint_);
}
EXPECT_EQ(2u, segment_names.size());
}
// Test allocation with multiple preferred segments
TEST_P(AllocationStrategyParameterizedTest,
MultiplePreferredSegmentsAllocation) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("preferred1", 0x10000000ULL);
auto allocator3 = CreateTestAllocator("preferred2", 0x20000000ULL);
auto allocator4 = CreateTestAllocator("segment4", 0x30000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("preferred1", allocator2);
allocator_manager.addAllocator("preferred2", allocator3);
allocator_manager.addAllocator("segment4", allocator4);
size_t slice_length = 1024;
std::vector<std::string> preferred_segments = {
"preferred1", "preferred2"}; // Multiple preferred segments
auto result = strategy_->Allocate(allocator_manager, slice_length, 2,
preferred_segments, {});
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 2);
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
std::string segment_ep = mem_desc.buffer_descriptor.transport_endpoint_;
EXPECT_TRUE(segment_ep == "preferred1" || segment_ep == "preferred2");
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
}
// Test allocation with excluded segments
TEST_P(AllocationStrategyParameterizedTest, ExcludedSegmentsAllocation) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("segment2", 0x10000000ULL);
auto allocator3 = CreateTestAllocator("segment3", 0x20000000ULL);
auto allocator4 = CreateTestAllocator("segment4", 0x30000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("segment2", allocator2);
allocator_manager.addAllocator("segment3", allocator3);
allocator_manager.addAllocator("segment4", allocator4);
size_t slice_length = 1024;
std::set<std::string> excluded_segments = {"segment1", "segment3"};
auto result = strategy_->Allocate(allocator_manager, slice_length,
3, // Requires 3 replicas
{}, excluded_segments);
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 2); // Only 2 replicas should be allocated
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
std::string segment_ep = mem_desc.buffer_descriptor.transport_endpoint_;
// Should not be allocated from excluded segments
EXPECT_NE(segment_ep, "segment1");
EXPECT_NE(segment_ep, "segment3");
EXPECT_TRUE(segment_ep == "segment2" || segment_ep == "segment4");
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
}
// Test allocation when all available segments are excluded
TEST_F(AllocationStrategyTest, AllSegmentsExcluded) {
auto allocator1 = std::make_shared<OffsetBufferAllocator>(
"segment1", 0x100000000ULL, 64 * MiB, "segment1");
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
size_t slice_length = 1024;
std::set<std::string> excluded_segments = {"segment1"};
auto result = strategy_->Allocate(allocator_manager, slice_length, 1, {},
excluded_segments);
EXPECT_FALSE(result.has_value());
EXPECT_EQ(result.error(), ErrorCode::NO_AVAILABLE_HANDLE);
}
// Test allocation with preferred segments and excluded segments combination
TEST_P(AllocationStrategyParameterizedTest,
PreferredAndExcludedSegmentsCombination) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("preferred", 0x10000000ULL);
auto allocator3 = CreateTestAllocator("segment3", 0x20000000ULL);
auto allocator4 = CreateTestAllocator("segment4", 0x30000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("preferred", allocator2);
allocator_manager.addAllocator("segment3", allocator3);
allocator_manager.addAllocator("segment4", allocator4);
size_t slice_length = 1024;
std::vector<std::string> preferred_segments = {"preferred"};
std::set<std::string> excluded_segments = {
"segment1"}; // Exclude a different segment
auto result = strategy_->Allocate(allocator_manager, slice_length,
3, // Requires 3 replicas
preferred_segments, excluded_segments);
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 3);
bool has_preferred_replica = false;
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
std::string segment_ep = mem_desc.buffer_descriptor.transport_endpoint_;
// Should not be allocated from excluded segments
EXPECT_NE(segment_ep, "segment1");
if (segment_ep == "preferred") {
has_preferred_replica = true;
}
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
EXPECT_TRUE(has_preferred_replica);
}
// Test allocation with preferred segments that are also excluded (exclude takes
// precedence)
TEST_P(AllocationStrategyParameterizedTest,
PreferredAndExcludedSegmentsConflict) {
auto allocator1 = CreateTestAllocator("segment1", 0);
auto allocator2 = CreateTestAllocator("segment2", 0x10000000ULL);
auto allocator3 = CreateTestAllocator("segment3", 0x20000000ULL);
AllocatorManager allocator_manager;
allocator_manager.addAllocator("segment1", allocator1);
allocator_manager.addAllocator("segment2", allocator2);
allocator_manager.addAllocator("segment3", allocator3);
size_t slice_length = 1024;
std::vector<std::string> preferred_segments = {
"segment1"}; // Will be excluded
std::set<std::string> excluded_segments = {
"segment1"}; // Exclude the preferred
auto result = strategy_->Allocate(allocator_manager, slice_length,
3, // Requires 3 replicas
preferred_segments, excluded_segments);
ASSERT_TRUE(result.has_value()); // Should still succeed by falling back to
// other segments
EXPECT_EQ(result.value().size(), 2); // Only 2 replicas should be allocated
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
std::string segment_ep = mem_desc.buffer_descriptor.transport_endpoint_;
EXPECT_NE(
segment_ep,
"segment1"); // Should not be allocated from excluded segments
EXPECT_TRUE(segment_ep == "segment2" || segment_ep == "segment3");
EXPECT_EQ(mem_desc.buffer_descriptor.size_, 1024);
}
}
// Test the performance of AllocationStrategy.
// Test FreeRatioFirst load balancing distribution with different sized segments
TEST_P(AllocationStrategyParameterizedTest,
FreeRatioFirstLoadBalancingDistribution) {
auto [strategy_type, allocator_type] = GetParam();
if (strategy_type != AllocationStrategyType::FREE_RATIO_FIRST) {
// This test is only for FreeRatioFirst strategy
GTEST_SKIP();
}
const auto kNumSegments = 3;
// Different sized segments to test utilization ratio balancing
std::array<size_t, kNumSegments> kSegmentSizes = {32 * MiB, 64 * MiB,
128 * MiB};
AllocatorManager allocator_manager;
for (size_t i = 0; i < kNumSegments; i++) {
const auto name = std::to_string(i) + "-segment";
allocator_manager.addAllocator(
name, CreateTestAllocator(name, i * 128 * MiB, kSegmentSizes[i]));
}
std::array<size_t, kNumSegments> count = {0};
size_t slice_length = 64 * 1024; // 64KB per allocation
const size_t kNumAllocations = 3000; // Total 192MB allocated
std::vector<std::vector<Replica>> test_replicas;
for (size_t i = 0; i < kNumAllocations; i++) {
auto result = strategy_->Allocate(allocator_manager, slice_length);
ASSERT_TRUE(result.has_value());
EXPECT_EQ(result.value().size(), 1);
for (const auto& replica : result.value()) {
auto descriptor = replica.get_descriptor();
ASSERT_TRUE(descriptor.is_memory_replica());
const auto& mem_desc = descriptor.get_memory_descriptor();
std::string segment_name =
mem_desc.buffer_descriptor.transport_endpoint_;
EXPECT_EQ(mem_desc.buffer_descriptor.size_, slice_length);
// Extract segment index from name "X-segment"
size_t segment_idx = segment_name[0] - '0';
ASSERT_LT(segment_idx, kNumSegments);
count[segment_idx]++;
}
test_replicas.push_back(std::move(result.value()));
}
// Calculate utilization ratio for each segment
std::cout << "\nFreeRatioFirst Load Balancing Results (Different Sized "
"Segments):\n";
std::cout << "Total allocations: " << kNumAllocations << " x "
<< (slice_length / 1024)
<< "KB = " << (kNumAllocations * slice_length / MiB) << "MB\n\n";
std::array<double, kNumSegments> utilization_ratios;
for (size_t i = 0; i < kNumSegments; i++) {
size_t allocated_bytes = count[i] * slice_length;
double utilization = (allocated_bytes * 100.0) / kSegmentSizes[i];
utilization_ratios[i] = utilization;
std::cout << "Segment " << i << " (" << (kSegmentSizes[i] / MiB)
<< "MB capacity):\n"
<< " Allocations: " << count[i] << " (" << std::fixed
<< std::setprecision(1)
<< (count[i] * 100.0 / kNumAllocations) << "% of total)\n"
<< " Allocated: " << (allocated_bytes / MiB) << "MB\n"
<< " Utilization: " << std::setprecision(1) << utilization
<< "%\n\n";
}
// FreeRatioFirst should balance utilization ratios across segments
// Even though segments have different capacities (32MB, 64MB, 128MB),
// their utilization ratios should be similar (within 15% difference)
double max_util =
*std::max_element(utilization_ratios.begin(), utilization_ratios.end());
double min_util =
*std::min_element(utilization_ratios.begin(), utilization_ratios.end());
double util_diff = max_util - min_util;
std::cout << "Utilization difference: " << std::setprecision(1) << util_diff
<< "%\n";
std::cout << "Expected: < 15% for good load balancing\n\n";
// Verify that utilization ratios are balanced (within 15%)
EXPECT_LT(util_diff, 15.0)
<< "FreeRatioFirst should balance utilization ratios";
}
// Test the performance comparison between strategies
TEST_F(AllocationStrategyTest, PerformanceComparison) {
const auto kNumSegments = 512;
const auto kSegmentBase = 0x100000000ULL;
const auto kSegmentSize = 64 * MiB;
const auto kNumAllocations = 5000;
const auto kAllocationSize = 4 * MiB;
// Construct and add allocators
AllocatorManager allocator_manager;
for (size_t i = 0; i < kNumSegments; i++) {
const auto name = "segment_" + std::to_string(i);
allocator_manager.addAllocator(
name, std::make_shared<OffsetBufferAllocator>(name, kSegmentBase,
kSegmentSize, name));
}
// Test Random strategy
auto random_strategy = std::make_unique<RandomAllocationStrategy>();
std::vector<std::vector<Replica>> random_replicas;
random_replicas.reserve(kNumAllocations);
auto random_start = std::chrono::steady_clock::now();
for (size_t i = 0; i < kNumAllocations; i++) {
auto result =
random_strategy->Allocate(allocator_manager, kAllocationSize);
ASSERT_TRUE(result.has_value());
ASSERT_EQ(result.value().size(), 1);
random_replicas.emplace_back(std::move(result.value()));
}
auto random_elapsed_us =
std::chrono::duration_cast<std::chrono::microseconds>(
std::chrono::steady_clock::now() - random_start);
random_replicas.clear();
// Test FreeRatioFirst strategy
auto frf_strategy = std::make_unique<FreeRatioFirstAllocationStrategy>();
std::vector<std::vector<Replica>> frf_replicas;
frf_replicas.reserve(kNumAllocations);
auto frf_start = std::chrono::steady_clock::now();
for (size_t i = 0; i < kNumAllocations; i++) {
auto result =
frf_strategy->Allocate(allocator_manager, kAllocationSize);
ASSERT_TRUE(result.has_value());
ASSERT_EQ(result.value().size(), 1);
frf_replicas.emplace_back(std::move(result.value()));
}
auto frf_elapsed_us = std::chrono::duration_cast<std::chrono::microseconds>(
std::chrono::steady_clock::now() - frf_start);
std::cout << "\nAllocation Strategy Performance Comparison:\n"
<< "Num segments: " << kNumSegments << "\n"
<< "Num allocations: " << kNumAllocations << "\n"
<< "Random strategy: " << random_elapsed_us.count() << " us\n"
<< "FreeRatioFirst strategy: " << frf_elapsed_us.count()
<< " us\n"
<< "Speedup: " << std::fixed << std::setprecision(2)
<< (static_cast<double>(random_elapsed_us.count()) /
frf_elapsed_us.count())
<< "x\n\n";
}
TEST_F(AllocationStrategyTest, PerformanceTest) {
const auto kNumSegments = 512;
const auto kSegmentBase = 0x100000000ULL;
const auto kSegmentSize = 64 * MiB;
const auto kNumAllocations = 5000;
const auto kAllocationSize = 4 * MiB;
// Construct and add allocators.
AllocatorManager allocator_manager;
for (size_t i = 0; i < kNumSegments; i++) {
const auto name = "segment_" + std::to_string(i);
allocator_manager.addAllocator(
name, std::make_shared<OffsetBufferAllocator>(name, kSegmentBase,
kSegmentSize, name));
}
std::vector<std::vector<Replica>> replicas;
replicas.reserve(kNumAllocations);
// Do allocations.
auto start = std::chrono::steady_clock::now();
for (size_t i = 0; i < kNumAllocations; i++) {
auto result = strategy_->Allocate(allocator_manager, kAllocationSize);
ASSERT_TRUE(result.has_value());
ASSERT_EQ(result.value().size(), 1);
replicas.emplace_back(std::move(result.value()));
}
auto elapsed_us = std::chrono::duration_cast<std::chrono::microseconds>(
std::chrono::steady_clock::now() - start);
std::cout << "\nAllocation Strategy Performance Test:\n"
<< "Num segments: " << kNumSegments << "\n"
<< "Num allocations: " << kNumAllocations << "\n"
<< "Time elapsed: " << elapsed_us.count() << " us\n\n";
}
// Note: The following unit tests for internal helper methods have been removed
// because those methods (allocateSingleBuffer, tryRandomAllocate,
// allocateSlice, resetRetryCount, getRetryCount) are no longer part of the
// public API. The functionality is now encapsulated within the Allocate()
// method.
} // namespace mooncake