add SetCapacity and GetCapacity for secondary cache (#10712)

Summary:
To support tuning secondary cache dynamically, add `SetCapacity()` and `GetCapacity()` for CompressedSecondaryCache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10712

Test Plan: Unit Tests

Reviewed By: anand1976

Differential Revision: D39685212

Pulled By: gitbw95

fbshipit-source-id: 19573c67237011927320207732b5de083cb87240

cache/compressed_secondary_cache.cc

@@ -178,6 +178,19 @@ Status CompressedSecondaryCache::Insert(const Slice& key, void* value,
 
 void CompressedSecondaryCache::Erase(const Slice& key) { cache_->Erase(key); }
 
+Status CompressedSecondaryCache::SetCapacity(size_t capacity) {
+  MutexLock l(&capacity_mutex_);
+  cache_options_.capacity = capacity;
+  cache_->SetCapacity(capacity);
+  return Status::OK();
+}
+
+Status CompressedSecondaryCache::GetCapacity(size_t& capacity) {
+  MutexLock l(&capacity_mutex_);
+  capacity = cache_options_.capacity;
+  return Status::OK();
+}
+
 std::string CompressedSecondaryCache::GetPrintableOptions() const {
   std::string ret;
   ret.reserve(20000);
@@ -194,8 +207,8 @@ std::string CompressedSecondaryCache::GetPrintableOptions() const {
 }
 
 CompressedSecondaryCache::CacheValueChunk*
-CompressedSecondaryCache::SplitValueIntoChunks(
-    const Slice& value, const CompressionType compression_type,
+CompressedSecondaryCache::SplitValueIntoChunks(const Slice& value,
+                                               CompressionType compression_type,
                                                size_t& charge) {
   assert(!value.empty());
   const char* src_ptr = value.data();

cache/compressed_secondary_cache.h

@@ -15,6 +15,7 @@
 #include "rocksdb/slice.h"
 #include "rocksdb/status.h"
 #include "util/compression.h"
+#include "util/mutexlock.h"
 
 namespace ROCKSDB_NAMESPACE {
 
@@ -22,7 +23,7 @@ class CompressedSecondaryCacheResultHandle : public SecondaryCacheResultHandle {
  public:
   CompressedSecondaryCacheResultHandle(void* value, size_t size)
       : value_(value), size_(size) {}
-  virtual ~CompressedSecondaryCacheResultHandle() override = default;
+  ~CompressedSecondaryCacheResultHandle() override = default;
 
   CompressedSecondaryCacheResultHandle(
       const CompressedSecondaryCacheResultHandle&) = delete;
@@ -78,7 +79,7 @@ class CompressedSecondaryCache : public SecondaryCache {
       CompressionType compression_type = CompressionType::kLZ4Compression,
       uint32_t compress_format_version = 2,
       bool enable_custom_split_merge = false);
-  virtual ~CompressedSecondaryCache() override;
+  ~CompressedSecondaryCache() override;
 
   const char* Name() const override { return "CompressedSecondaryCache"; }
 
@@ -95,6 +96,10 @@ class CompressedSecondaryCache : public SecondaryCache {
 
   void WaitAll(std::vector<SecondaryCacheResultHandle*> /*handles*/) override {}
 
+  Status SetCapacity(size_t capacity) override;
+
+  Status GetCapacity(size_t& capacity) override;
+
   std::string GetPrintableOptions() const override;
 
  private:
@@ -116,7 +121,7 @@ class CompressedSecondaryCache : public SecondaryCache {
   // are stored in CacheValueChunk and extra charge is needed for each chunk,
   // so the cache charge is recalculated here.
   CacheValueChunk* SplitValueIntoChunks(const Slice& value,
-                                        const CompressionType compression_type,
+                                        CompressionType compression_type,
                                         size_t& charge);
 
   // After merging chunks, the extra charge for each chunk is removed, so
@@ -128,6 +133,7 @@ class CompressedSecondaryCache : public SecondaryCache {
   static Cache::DeleterFn GetDeletionCallback(bool enable_custom_split_merge);
   std::shared_ptr<Cache> cache_;
   CompressedSecondaryCacheOptions cache_options_;
+  mutable port::Mutex capacity_mutex_;
 };
 
 }  // namespace ROCKSDB_NAMESPACE

cache/compressed_secondary_cache_test.cc

@@ -5,28 +5,21 @@
 
 #include "cache/compressed_secondary_cache.h"
 
-#include <algorithm>
-#include <cstdint>
 #include <iterator>
+#include <memory>
 #include <tuple>
 
-#include "cache/lru_cache.h"
 #include "memory/jemalloc_nodump_allocator.h"
-#include "memory/memory_allocator.h"
-#include "rocksdb/compression_type.h"
 #include "rocksdb/convenience.h"
-#include "rocksdb/secondary_cache.h"
 #include "test_util/testharness.h"
 #include "test_util/testutil.h"
-#include "util/compression.h"
-#include "util/random.h"
 
 namespace ROCKSDB_NAMESPACE {
 
 class CompressedSecondaryCacheTest : public testing::Test {
  public:
   CompressedSecondaryCacheTest() : fail_create_(false) {}
-  ~CompressedSecondaryCacheTest() {}
+  ~CompressedSecondaryCacheTest() override = default;
 
  protected:
   class TestItem {
@@ -34,10 +27,10 @@ class CompressedSecondaryCacheTest : public testing::Test {
     TestItem(const char* buf, size_t size) : buf_(new char[size]), size_(size) {
       memcpy(buf_.get(), buf, size);
     }
-    ~TestItem() {}
+    ~TestItem() = default;
 
     char* Buf() { return buf_.get(); }
-    size_t Size() { return size_; }
+    [[nodiscard]] size_t Size() const { return size_; }
 
    private:
     std::unique_ptr<char[]> buf_;
@@ -50,7 +43,7 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
   static Status SaveToCallback(void* from_obj, size_t from_offset,
                                size_t length, void* out) {
-    TestItem* item = reinterpret_cast<TestItem*>(from_obj);
+    auto item = reinterpret_cast<TestItem*>(from_obj);
     const char* buf = item->Buf();
     EXPECT_EQ(length, item->Size());
     EXPECT_EQ(from_offset, 0);
@@ -315,12 +308,12 @@ class CompressedSecondaryCacheTest : public testing::Test {
     get_perf_context()->Reset();
     Random rnd(301);
     std::string str1 = rnd.RandomString(1001);
-    TestItem* item1_1 = new TestItem(str1.data(), str1.length());
+    auto item1_1 = new TestItem(str1.data(), str1.length());
     ASSERT_OK(cache->Insert(
         "k1", item1_1, &CompressedSecondaryCacheTest::helper_, str1.length()));
 
     std::string str2 = rnd.RandomString(1012);
-    TestItem* item2_1 = new TestItem(str2.data(), str2.length());
+    auto item2_1 = new TestItem(str2.data(), str2.length());
     // After this Insert, primary cache contains k2 and secondary cache contains
     // k1's dummy item.
     ASSERT_OK(cache->Insert(
@@ -330,7 +323,7 @@ class CompressedSecondaryCacheTest : public testing::Test {
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
 
     std::string str3 = rnd.RandomString(1024);
-    TestItem* item3_1 = new TestItem(str3.data(), str3.length());
+    auto item3_1 = new TestItem(str3.data(), str3.length());
     // After this Insert, primary cache contains k3 and secondary cache contains
     // k1's dummy item and k2's dummy item.
     ASSERT_OK(cache->Insert(
@@ -339,14 +332,14 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
     // After this Insert, primary cache contains k1 and secondary cache contains
     // k1's dummy item, k2's dummy item, and k3's dummy item.
-    TestItem* item1_2 = new TestItem(str1.data(), str1.length());
+    auto item1_2 = new TestItem(str1.data(), str1.length());
     ASSERT_OK(cache->Insert(
         "k1", item1_2, &CompressedSecondaryCacheTest::helper_, str1.length()));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 3);
 
     // After this Insert, primary cache contains k2 and secondary cache contains
     // k1's item, k2's dummy item, and k3's dummy item.
-    TestItem* item2_2 = new TestItem(str2.data(), str2.length());
+    auto item2_2 = new TestItem(str2.data(), str2.length());
     ASSERT_OK(cache->Insert(
         "k2", item2_2, &CompressedSecondaryCacheTest::helper_, str2.length()));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 1);
@@ -362,7 +355,7 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
     // After this Insert, primary cache contains k3 and secondary cache contains
     // k1's item and k2's item.
-    TestItem* item3_2 = new TestItem(str3.data(), str3.length());
+    auto item3_2 = new TestItem(str3.data(), str3.length());
     ASSERT_OK(cache->Insert(
         "k3", item3_2, &CompressedSecondaryCacheTest::helper_, str3.length()));
     ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 2);
@@ -381,7 +374,7 @@ class CompressedSecondaryCacheTest : public testing::Test {
                            test_item_creator, Cache::Priority::LOW, true,
                            stats.get());
     ASSERT_NE(handle, nullptr);
-    TestItem* val3 = static_cast<TestItem*>(cache->Value(handle));
+    auto val3 = static_cast<TestItem*>(cache->Value(handle));
     ASSERT_NE(val3, nullptr);
     ASSERT_EQ(memcmp(val3->Buf(), item3_2->Buf(), item3_2->Size()), 0);
     cache->Release(handle);
@@ -399,18 +392,20 @@ class CompressedSecondaryCacheTest : public testing::Test {
                            stats.get());
     ASSERT_NE(handle, nullptr);
     ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 1);
-    TestItem* val1_1 = static_cast<TestItem*>(cache->Value(handle));
+    auto val1_1 = static_cast<TestItem*>(cache->Value(handle));
     ASSERT_NE(val1_1, nullptr);
     ASSERT_EQ(memcmp(val1_1->Buf(), str1.data(), str1.size()), 0);
     cache->Release(handle);
 
     // This Lookup should erase k1 from the secondary cache and insert
     // it into primary cache; then k3 is demoted.
+    // k2 and k3 are in secondary cache.
     handle = cache->Lookup("k1", &CompressedSecondaryCacheTest::helper_,
                            test_item_creator, Cache::Priority::LOW, true,
                            stats.get());
     ASSERT_NE(handle, nullptr);
     ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 1);
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 3);
     cache->Release(handle);
 
     // k2 is still in secondary cache.
@@ -421,6 +416,54 @@ class CompressedSecondaryCacheTest : public testing::Test {
     ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 2);
     cache->Release(handle);
 
+    // Testing SetCapacity().
+    ASSERT_OK(secondary_cache->SetCapacity(0));
+    handle = cache->Lookup("k3", &CompressedSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, true,
+                           stats.get());
+    ASSERT_EQ(handle, nullptr);
+
+    ASSERT_OK(secondary_cache->SetCapacity(7000));
+    size_t capacity;
+    ASSERT_OK(secondary_cache->GetCapacity(capacity));
+    ASSERT_EQ(capacity, 7000);
+    auto item1_3 = new TestItem(str1.data(), str1.length());
+    // After this Insert, primary cache contains k1.
+    ASSERT_OK(cache->Insert(
+        "k1", item1_3, &CompressedSecondaryCacheTest::helper_, str2.length()));
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 3);
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 4);
+
+    auto item2_3 = new TestItem(str2.data(), str2.length());
+    // After this Insert, primary cache contains k2 and secondary cache contains
+    // k1's dummy item.
+    ASSERT_OK(cache->Insert(
+        "k2", item2_3, &CompressedSecondaryCacheTest::helper_, str1.length()));
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 4);
+
+    auto item1_4 = new TestItem(str1.data(), str1.length());
+    // After this Insert, primary cache contains k1 and secondary cache contains
+    // k1's dummy item and k2's dummy item.
+    ASSERT_OK(cache->Insert(
+        "k1", item1_4, &CompressedSecondaryCacheTest::helper_, str2.length()));
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 5);
+
+    auto item2_4 = new TestItem(str2.data(), str2.length());
+    // After this Insert, primary cache contains k2 and secondary cache contains
+    // k1's real item and k2's dummy item.
+    ASSERT_OK(cache->Insert(
+        "k2", item2_4, &CompressedSecondaryCacheTest::helper_, str2.length()));
+    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 5);
+    // This Lookup should just insert a dummy handle in the primary cache
+    // and the k1 is still in the secondary cache.
+    handle = cache->Lookup("k1", &CompressedSecondaryCacheTest::helper_,
+                           test_item_creator, Cache::Priority::LOW, true,
+                           stats.get());
+
+    ASSERT_NE(handle, nullptr);
+    cache->Release(handle);
+    ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 3);
+
     cache.reset();
     secondary_cache.reset();
   }
@@ -452,8 +495,7 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
     Random rnd(301);
     std::string str1 = rnd.RandomString(1001);
-    auto item1 =
-        std::unique_ptr<TestItem>(new TestItem(str1.data(), str1.length()));
+    auto item1 = std::make_unique<TestItem>(str1.data(), str1.length());
     ASSERT_NOK(cache->Insert("k1", item1.get(), nullptr, str1.length()));
     ASSERT_OK(cache->Insert("k1", item1.get(),
                             &CompressedSecondaryCacheTest::helper_,
@@ -500,13 +542,13 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
     Random rnd(301);
     std::string str1 = rnd.RandomString(1001);
-    TestItem* item1 = new TestItem(str1.data(), str1.length());
+    auto item1 = new TestItem(str1.data(), str1.length());
     ASSERT_OK(cache->Insert("k1", item1,
                             &CompressedSecondaryCacheTest::helper_fail_,
                             str1.length()));
 
     std::string str2 = rnd.RandomString(1002);
-    TestItem* item2 = new TestItem(str2.data(), str2.length());
+    auto item2 = new TestItem(str2.data(), str2.length());
     // k1 should be demoted to the secondary cache.
     ASSERT_OK(cache->Insert("k2", item2,
                             &CompressedSecondaryCacheTest::helper_fail_,
@@ -559,12 +601,12 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
     Random rnd(301);
     std::string str1 = rnd.RandomString(1001);
-    TestItem* item1 = new TestItem(str1.data(), str1.length());
+    auto item1 = new TestItem(str1.data(), str1.length());
     ASSERT_OK(cache->Insert("k1", item1, &CompressedSecondaryCacheTest::helper_,
                             str1.length()));
 
     std::string str2 = rnd.RandomString(1002);
-    TestItem* item2 = new TestItem(str2.data(), str2.length());
+    auto item2 = new TestItem(str2.data(), str2.length());
     // k1 should be demoted to the secondary cache.
     ASSERT_OK(cache->Insert("k2", item2, &CompressedSecondaryCacheTest::helper_,
                             str2.length()));
@@ -617,13 +659,13 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
     Random rnd(301);
     std::string str1 = rnd.RandomString(1001);
-    TestItem* item1_1 = new TestItem(str1.data(), str1.length());
+    auto item1_1 = new TestItem(str1.data(), str1.length());
     ASSERT_OK(cache->Insert(
         "k1", item1_1, &CompressedSecondaryCacheTest::helper_, str1.length()));
 
     std::string str2 = rnd.RandomString(1002);
     std::string str2_clone{str2};
-    TestItem* item2 = new TestItem(str2.data(), str2.length());
+    auto item2 = new TestItem(str2.data(), str2.length());
     // After this Insert, primary cache contains k2 and secondary cache contains
     // k1's dummy item.
     ASSERT_OK(cache->Insert("k2", item2, &CompressedSecondaryCacheTest::helper_,
@@ -631,11 +673,11 @@ class CompressedSecondaryCacheTest : public testing::Test {
 
     // After this Insert, primary cache contains k1 and secondary cache contains
     // k1's dummy item and k2's dummy item.
-    TestItem* item1_2 = new TestItem(str1.data(), str1.length());
+    auto item1_2 = new TestItem(str1.data(), str1.length());
     ASSERT_OK(cache->Insert(
         "k1", item1_2, &CompressedSecondaryCacheTest::helper_, str1.length()));
 
-    TestItem* item2_2 = new TestItem(str2.data(), str2.length());
+    auto item2_2 = new TestItem(str2.data(), str2.length());
     // After this Insert, primary cache contains k2 and secondary cache contains
     // k1's item and k2's dummy item.
     ASSERT_OK(cache->Insert(

include/rocksdb/secondary_cache.h

@@ -24,7 +24,7 @@ namespace ROCKSDB_NAMESPACE {
 // handle successfullly read the item.
 class SecondaryCacheResultHandle {
  public:
-  virtual ~SecondaryCacheResultHandle() {}
+  virtual ~SecondaryCacheResultHandle() = default;
 
   // Returns whether the handle is ready or not
   virtual bool IsReady() = 0;
@@ -49,7 +49,7 @@ class SecondaryCacheResultHandle {
 // including data loss, unreported corruption, deadlocks, and more.
 class SecondaryCache : public Customizable {
  public:
-  virtual ~SecondaryCache() {}
+  ~SecondaryCache() override = default;
 
   static const char* Type() { return "SecondaryCache"; }
   static Status CreateFromString(const ConfigOptions& config_options,
@@ -83,7 +83,7 @@ class SecondaryCache : public Customizable {
       bool advise_erase, bool& is_in_sec_cache) = 0;
 
   // Indicate whether a handle can be erased in this secondary cache.
-  virtual bool SupportForceErase() const = 0;
+  [[nodiscard]] virtual bool SupportForceErase() const = 0;
 
   // At the discretion of the implementation, erase the data associated
   // with key.
@@ -92,7 +92,20 @@ class SecondaryCache : public Customizable {
   // Wait for a collection of handles to become ready.
   virtual void WaitAll(std::vector<SecondaryCacheResultHandle*> handles) = 0;
 
-  virtual std::string GetPrintableOptions() const = 0;
+  // Set the maximum configured capacity of the cache.
+  // When the new capacity is less than the old capacity and the existing usage
+  // is greater than new capacity, the implementation will do its best job to
+  // purge the released entries from the cache in order to lower the usage.
+  //
+  // The derived class can make this function no-op and return NotSupported().
+  virtual Status SetCapacity(size_t /* capacity */) {
+    return Status::NotSupported();
+  }
+
+  // The derived class can make this function no-op and return NotSupported().
+  virtual Status GetCapacity(size_t& /* capacity */) {
+    return Status::NotSupported();
+  }
 };
 
 }  // namespace ROCKSDB_NAMESPACE

utilities/fault_injection_secondary_cache.h

@@ -44,6 +44,14 @@ class FaultInjectionSecondaryCache : public SecondaryCache {
 
   void WaitAll(std::vector<SecondaryCacheResultHandle*> handles) override;
 
+  Status SetCapacity(size_t capacity) override {
+    return base_->SetCapacity(capacity);
+  }
+
+  Status GetCapacity(size_t& capacity) override {
+    return base_->GetCapacity(capacity);
+  }
+
   std::string GetPrintableOptions() const override {
     return base_->GetPrintableOptions();
   }