Make RateLimiter not Customizable (#10378)

Summary: (PR created for informational/testing purposes only.) - Fixes lost dynamic updates to GenericRateLimiter bandwidth using `SetBytesPerSecond()` - Benefit over #10374 is eliminating race conditions with Configurable framework. Pull Request resolved: #10378 Differential Revision: D37914865 fbshipit-source-id: e2b455eb30058f9eea5fb2af870eaa7c77da6969
facebook · Jul 18, 2022 · be076a3 · be076a3
1 parent ec4ebef
commit be076a3
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diff --git a/HISTORY.md b/HISTORY.md
@@ -1,5 +1,10 @@
 # Rocksdb Change Log
 ## Unreleased
+### Public API changes
+* Removed Customizable support for RateLimiter and removed its CreateFromString() and Type() functions.
+
+### Bug Fixes
+* Fix a bug where `GenericRateLimiter` could revert the bandwidth set dynamically using `SetBytesPerSecond()` when a user configures a structure enclosing it, e.g., using `GetOptionsFromString()` to configure an `Options` that references an existing `RateLimiter` object.
 
 ## 7.5.0 (07/15/2022)
 ### New Features

diff --git a/db/db_test.cc b/db/db_test.cc
@@ -4101,9 +4101,6 @@ class MockedRateLimiterWithNoOptionalAPIImpl : public RateLimiter {
 
   ~MockedRateLimiterWithNoOptionalAPIImpl() override {}
 
-  const char* Name() const override {
-    return "MockedRateLimiterWithNoOptionalAPI";
-  }
   void SetBytesPerSecond(int64_t bytes_per_second) override {
     (void)bytes_per_second;
   }

diff --git a/include/rocksdb/rate_limiter.h b/include/rocksdb/rate_limiter.h
@@ -9,7 +9,6 @@
 
 #pragma once
 
-#include "rocksdb/customizable.h"
 #include "rocksdb/env.h"
 #include "rocksdb/statistics.h"
 #include "rocksdb/status.h"
@@ -19,7 +18,7 @@ namespace ROCKSDB_NAMESPACE {
 // Exceptions MUST NOT propagate out of overridden functions into RocksDB,
 // because RocksDB is not exception-safe. This could cause undefined behavior
 // including data loss, unreported corruption, deadlocks, and more.
-class RateLimiter : public Customizable {
+class RateLimiter {
  public:
   enum class OpType {
     kRead,
@@ -32,20 +31,11 @@ class RateLimiter : public Customizable {
     kAllIo,
   };
 
-  static const char* Type() { return "RateLimiter"; }
-  static Status CreateFromString(const ConfigOptions& options,
-                                 const std::string& value,
-                                 std::shared_ptr<RateLimiter>* result);
-
   // For API compatibility, default to rate-limiting writes only.
-  explicit RateLimiter(Mode mode = Mode::kWritesOnly);
+  explicit RateLimiter(Mode mode = Mode::kWritesOnly) : mode_(mode) {}
 
   virtual ~RateLimiter() {}
 
-  // Deprecated. Will be removed in a major release. Derived classes
-  // should implement this method.
-  virtual const char* Name() const override { return ""; }
-
   // This API allows user to dynamically change rate limiter's bytes per second.
   // REQUIRED: bytes_per_second > 0
   virtual void SetBytesPerSecond(int64_t bytes_per_second) = 0;
@@ -135,7 +125,7 @@ class RateLimiter : public Customizable {
   Mode GetMode() { return mode_; }
 
  private:
-  Mode mode_;
+  const Mode mode_;
 };
 
 // Create a RateLimiter object, which can be shared among RocksDB instances to

diff --git a/options/customizable_test.cc b/options/customizable_test.cc
@@ -27,7 +27,6 @@
 #include "rocksdb/filter_policy.h"
 #include "rocksdb/flush_block_policy.h"
 #include "rocksdb/memory_allocator.h"
-#include "rocksdb/rate_limiter.h"
 #include "rocksdb/secondary_cache.h"
 #include "rocksdb/slice_transform.h"
 #include "rocksdb/sst_partitioner.h"
@@ -42,7 +41,6 @@
 #include "test_util/testharness.h"
 #include "test_util/testutil.h"
 #include "util/file_checksum_helper.h"
-#include "util/rate_limiter.h"
 #include "util/string_util.h"
 #include "utilities/compaction_filters/remove_emptyvalue_compactionfilter.h"
 #include "utilities/memory_allocators.h"
@@ -1472,21 +1470,6 @@ class MockFileChecksumGenFactory : public FileChecksumGenFactory {
   }
 };
 
-class MockRateLimiter : public RateLimiter {
- public:
-  static const char* kClassName() { return "MockRateLimiter"; }
-  const char* Name() const override { return kClassName(); }
-  void SetBytesPerSecond(int64_t /*bytes_per_second*/) override {}
-  int64_t GetBytesPerSecond() const override { return 0; }
-  int64_t GetSingleBurstBytes() const override { return 0; }
-  int64_t GetTotalBytesThrough(const Env::IOPriority /*pri*/) const override {
-    return 0;
-  }
-  int64_t GetTotalRequests(const Env::IOPriority /*pri*/) const override {
-    return 0;
-  }
-};
-
 class MockFilterPolicy : public FilterPolicy {
  public:
   static const char* kClassName() { return "MockFilterPolicy"; }
@@ -1618,14 +1601,6 @@ static int RegisterLocalObjects(ObjectLibrary& library,
         return guard->get();
       });
 
-  library.AddFactory<RateLimiter>(
-      MockRateLimiter::kClassName(),
-      [](const std::string& /*uri*/, std::unique_ptr<RateLimiter>* guard,
-         std::string* /* errmsg */) {
-        guard->reset(new MockRateLimiter());
-        return guard->get();
-      });
-
   library.AddFactory<const FilterPolicy>(
       MockFilterPolicy::kClassName(),
       [](const std::string& /*uri*/, std::unique_ptr<const FilterPolicy>* guard,
@@ -2149,37 +2124,6 @@ TEST_F(LoadCustomizableTest, LoadMemoryAllocatorTest) {
   }
 }
 
-TEST_F(LoadCustomizableTest, LoadRateLimiterTest) {
-#ifndef ROCKSDB_LITE
-  ASSERT_OK(TestSharedBuiltins<RateLimiter>(MockRateLimiter::kClassName(),
-                                            GenericRateLimiter::kClassName()));
-#else
-  ASSERT_OK(TestSharedBuiltins<RateLimiter>(MockRateLimiter::kClassName(), ""));
-#endif  // ROCKSDB_LITE
-
-  std::shared_ptr<RateLimiter> result;
-  ASSERT_OK(RateLimiter::CreateFromString(
-      config_options_, std::string(GenericRateLimiter::kClassName()) + ":1234",
-      &result));
-  ASSERT_NE(result, nullptr);
-  ASSERT_TRUE(result->IsInstanceOf(GenericRateLimiter::kClassName()));
-#ifndef ROCKSDB_LITE
-  ASSERT_OK(GetDBOptionsFromString(
-      config_options_, db_opts_,
-      std::string("rate_limiter=") + GenericRateLimiter::kClassName(),
-      &db_opts_));
-  ASSERT_NE(db_opts_.rate_limiter, nullptr);
-  if (RegisterTests("Test")) {
-    ExpectCreateShared<RateLimiter>(MockRateLimiter::kClassName());
-    ASSERT_OK(GetDBOptionsFromString(
-        config_options_, db_opts_,
-        std::string("rate_limiter=") + MockRateLimiter::kClassName(),
-        &db_opts_));
-    ASSERT_NE(db_opts_.rate_limiter, nullptr);
-  }
-#endif  // ROCKSDB_LITE
-}
-
 TEST_F(LoadCustomizableTest, LoadFilterPolicyTest) {
   const std::string kAutoBloom = BloomFilterPolicy::kClassName();
   const std::string kAutoRibbon = RibbonFilterPolicy::kClassName();

diff --git a/options/db_options.cc b/options/db_options.cc
@@ -421,12 +421,11 @@ static std::unordered_map<std::string, OptionTypeInfo>
         {"db_host_id",
          {offsetof(struct ImmutableDBOptions, db_host_id), OptionType::kString,
           OptionVerificationType::kNormal, OptionTypeFlags::kCompareNever}},
+        // Temporarily deprecated due to race conditions (examples in PR 10375).
         {"rate_limiter",
-         OptionTypeInfo::AsCustomSharedPtr<RateLimiter>(
-             offsetof(struct ImmutableDBOptions, rate_limiter),
-             OptionVerificationType::kNormal,
-             OptionTypeFlags::kCompareNever | OptionTypeFlags::kAllowNull)},
-
+         {offsetof(struct ImmutableDBOptions, rate_limiter),
+          OptionType::kUnknown, OptionVerificationType::kDeprecated,
+          OptionTypeFlags::kDontSerialize | OptionTypeFlags::kCompareNever}},
         // The following properties were handled as special cases in ParseOption
         // This means that the properties could be read from the options file
         // but never written to the file or compared to each other.