diff --git a/HISTORY.md b/HISTORY.md
index 68e0816bdf..dc4b320a67 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -16,6 +16,7 @@
 * Add stats for ReadAsync time spent and async read errors.
 * Basic support for the wide-column data model is now available. Wide-column entities can be stored using the `PutEntity` API, and retrieved using `GetEntity` and the new `columns` API of iterator. For compatibility, the classic APIs `Get` and `MultiGet`, as well as iterator's `value` API return the value of the anonymous default column of wide-column entities; also, `GetEntity` and iterator's `columns` return any plain key-values in the form of an entity which only has the anonymous default column. `Merge` (and `GetMergeOperands`) currently also apply to the default column; any other columns of entities are unaffected by `Merge` operations. Note that some features like compaction filters, transactions, user-defined timestamps, and the SST file writer do not yet support wide-column entities; also, there is currently no `MultiGet`-like API to retrieve multiple entities at once. We plan to gradually close the above gaps and also implement new features like column-level operations (e.g. updating or querying only certain columns of an entity).
 * Marked HyperClockCache as a production-ready alternative to LRUCache for the block cache. HyperClockCache greatly improves hot-path CPU efficiency under high parallel load or high contention, with some documented caveats and limitations. As much as 4.5x higher ops/sec vs. LRUCache has been seen in db_bench under high parallel load.
+* Add periodic diagnostics to info_log (LOG file) for HyperClockCache block cache if performance is degraded by bad `estimated_entry_charge` option.
 
 ### Public API Changes
 * Marked `block_cache_compressed` as a deprecated feature. Use SecondaryCache instead.
diff --git a/cache/clock_cache.cc b/cache/clock_cache.cc
index 1ddb8d8ca8..6c9f18c2fb 100644
--- a/cache/clock_cache.cc
+++ b/cache/clock_cache.cc
@@ -11,8 +11,10 @@
 
 #include <cassert>
 #include <functional>
+#include <numeric>
 
 #include "cache/cache_key.h"
+#include "logging/logging.h"
 #include "monitoring/perf_context_imp.h"
 #include "monitoring/statistics.h"
 #include "port/lang.h"
@@ -1152,6 +1154,16 @@ size_t ClockCacheShard<Table>::GetUsage() const {
   return table_.GetUsage();
 }
 
+template <class Table>
+size_t ClockCacheShard<Table>::GetDetachedUsage() const {
+  return table_.GetDetachedUsage();
+}
+
+template <class Table>
+size_t ClockCacheShard<Table>::GetCapacity() const {
+  return capacity_;
+}
+
 template <class Table>
 size_t ClockCacheShard<Table>::GetPinnedUsage() const {
   // Computes the pinned usage by scanning the whole hash table. This
@@ -1186,6 +1198,11 @@ size_t ClockCacheShard<Table>::GetOccupancyCount() const {
   return table_.GetOccupancy();
 }
 
+template <class Table>
+size_t ClockCacheShard<Table>::GetOccupancyLimit() const {
+  return table_.GetOccupancyLimit();
+}
+
 template <class Table>
 size_t ClockCacheShard<Table>::GetTableAddressCount() const {
   return table_.GetTableSize();
@@ -1227,6 +1244,135 @@ Cache::DeleterFn HyperClockCache::GetDeleter(Handle* handle) const {
   return h->deleter;
 }
 
+namespace {
+
+// For each cache shard, estimate what the table load factor would be if
+// cache filled to capacity with average entries. This is considered
+// indicative of a potential problem if the shard is essentially operating
+// "at limit", which we define as high actual usage (>80% of capacity)
+// or actual occupancy very close to limit (>95% of limit).
+// Also, for each shard compute the recommended estimated_entry_charge,
+// and keep the minimum one for use as overall recommendation.
+void AddShardEvaluation(const HyperClockCache::Shard& shard,
+                        std::vector<double>& predicted_load_factors,
+                        size_t& min_recommendation) {
+  size_t usage = shard.GetUsage() - shard.GetDetachedUsage();
+  size_t capacity = shard.GetCapacity();
+  double usage_ratio = 1.0 * usage / capacity;
+
+  size_t occupancy = shard.GetOccupancyCount();
+  size_t occ_limit = shard.GetOccupancyLimit();
+  double occ_ratio = 1.0 * occupancy / occ_limit;
+  if (usage == 0 || occupancy == 0 || (usage_ratio < 0.8 && occ_ratio < 0.95)) {
+    // Skip as described above
+    return;
+  }
+
+  // If filled to capacity, what would the occupancy ratio be?
+  double ratio = occ_ratio / usage_ratio;
+  // Given max load factor, what that load factor be?
+  double lf = ratio * kStrictLoadFactor;
+  predicted_load_factors.push_back(lf);
+
+  // Update min_recommendation also
+  size_t recommendation = usage / occupancy;
+  min_recommendation = std::min(min_recommendation, recommendation);
+}
+
+}  // namespace
+
+void HyperClockCache::ReportProblems(
+    const std::shared_ptr<Logger>& info_log) const {
+  uint32_t shard_count = GetNumShards();
+  std::vector<double> predicted_load_factors;
+  size_t min_recommendation = SIZE_MAX;
+  const_cast<HyperClockCache*>(this)->ForEachShard(
+      [&](HyperClockCache::Shard* shard) {
+        AddShardEvaluation(*shard, predicted_load_factors, min_recommendation);
+      });
+
+  if (predicted_load_factors.empty()) {
+    // None operating "at limit" -> nothing to report
+    return;
+  }
+  std::sort(predicted_load_factors.begin(), predicted_load_factors.end());
+
+  // First, if the average load factor is within spec, we aren't going to
+  // complain about a few shards being out of spec.
+  // NOTE: this is only the average among cache shards operating "at limit,"
+  // which should be representative of what we care about. It it normal, even
+  // desirable, for a cache to operate "at limit" so this should not create
+  // selection bias. See AddShardEvaluation().
+  // TODO: Consider detecting cases where decreasing the number of shards
+  // would be good, e.g. serious imbalance among shards.
+  double average_load_factor =
+      std::accumulate(predicted_load_factors.begin(),
+                      predicted_load_factors.end(), 0.0) /
+      shard_count;
+
+  constexpr double kLowSpecLoadFactor = kLoadFactor / 2;
+  constexpr double kMidSpecLoadFactor = kLoadFactor / 1.414;
+  if (average_load_factor > kLoadFactor) {
+    // Out of spec => Consider reporting load factor too high
+    // Estimate effective overall capacity loss due to enforcing occupancy limit
+    double lost_portion = 0.0;
+    int over_count = 0;
+    for (double lf : predicted_load_factors) {
+      if (lf > kStrictLoadFactor) {
+        ++over_count;
+        lost_portion += (lf - kStrictLoadFactor) / lf / shard_count;
+      }
+    }
+    // >= 20% loss -> error
+    // >= 10% loss -> consistent warning
+    // >= 1% loss -> intermittent warning
+    InfoLogLevel level = InfoLogLevel::INFO_LEVEL;
+    bool report = true;
+    if (lost_portion > 0.2) {
+      level = InfoLogLevel::ERROR_LEVEL;
+    } else if (lost_portion > 0.1) {
+      level = InfoLogLevel::WARN_LEVEL;
+    } else if (lost_portion > 0.01) {
+      int report_percent = static_cast<int>(lost_portion * 100.0);
+      if (Random::GetTLSInstance()->PercentTrue(report_percent)) {
+        level = InfoLogLevel::WARN_LEVEL;
+      }
+    } else {
+      // don't report
+      report = false;
+    }
+    if (report) {
+      ROCKS_LOG_AT_LEVEL(
+          info_log, level,
+          "HyperClockCache@%p unable to use estimated %.1f%% capacity because "
+          "of "
+          "full occupancy in %d/%u cache shards (estimated_entry_charge too "
+          "high). Recommend estimated_entry_charge=%zu",
+          this, lost_portion * 100.0, over_count, (unsigned)shard_count,
+          min_recommendation);
+    }
+  } else if (average_load_factor < kLowSpecLoadFactor) {
+    // Out of spec => Consider reporting load factor too low
+    // But cautiously because low is not as big of a problem.
+
+    // Only report if highest occupancy shard is also below
+    // spec and only if average is substantially out of spec
+    if (predicted_load_factors.back() < kLowSpecLoadFactor &&
+        average_load_factor < kLowSpecLoadFactor / 1.414) {
+      InfoLogLevel level = InfoLogLevel::INFO_LEVEL;
+      if (average_load_factor < kLowSpecLoadFactor / 2) {
+        level = InfoLogLevel::WARN_LEVEL;
+      }
+      ROCKS_LOG_AT_LEVEL(
+          info_log, level,
+          "HyperClockCache@%p table has low occupancy at full capacity. Higher "
+          "estimated_entry_charge (about %.1fx) would likely improve "
+          "performance. Recommend estimated_entry_charge=%zu",
+          this, kMidSpecLoadFactor / average_load_factor, min_recommendation);
+    }
+  }
+}
+
 }  // namespace clock_cache
 
 // DEPRECATED (see public API)
diff --git a/cache/clock_cache.h b/cache/clock_cache.h
index c0be6a5f8d..ef1b0ccb75 100644
--- a/cache/clock_cache.h
+++ b/cache/clock_cache.h
@@ -440,6 +440,8 @@ class HyperClockTable {
     return occupancy_.load(std::memory_order_relaxed);
   }
 
+  size_t GetOccupancyLimit() const { return occupancy_limit_; }
+
   size_t GetUsage() const { return usage_.load(std::memory_order_relaxed); }
 
   size_t GetDetachedUsage() const {
@@ -612,12 +614,18 @@ class ALIGN_AS(CACHE_LINE_SIZE) ClockCacheShard final : public CacheShardBase {
 
   void Erase(const Slice& key, const UniqueId64x2& hashed_key);
 
+  size_t GetCapacity() const;
+
   size_t GetUsage() const;
 
+  size_t GetDetachedUsage() const;
+
   size_t GetPinnedUsage() const;
 
   size_t GetOccupancyCount() const;
 
+  size_t GetOccupancyLimit() const;
+
   size_t GetTableAddressCount() const;
 
   void ApplyToSomeEntries(
@@ -683,6 +691,9 @@ class HyperClockCache
   size_t GetCharge(Handle* handle) const override;
 
   DeleterFn GetDeleter(Handle* handle) const override;
+
+  void ReportProblems(
+      const std::shared_ptr<Logger>& /*info_log*/) const override;
 };  // class HyperClockCache
 
 }  // namespace clock_cache
diff --git a/db/db_block_cache_test.cc b/db/db_block_cache_test.cc
index 6ef1e6d693..db80b82cb2 100644
--- a/db/db_block_cache_test.cc
+++ b/db/db_block_cache_test.cc
@@ -1302,11 +1302,6 @@ TEST_F(DBBlockCacheTest, CacheEntryRoleStats) {
               capacity,
               BlockBasedTableOptions().block_size /*estimated_value_size*/)
               .MakeSharedCache()}) {
-      if (!cache) {
-        // Skip clock cache when not supported
-        continue;
-      }
-
       ++iterations_tested;
 
       Options options = CurrentOptions();
@@ -1539,6 +1534,124 @@ TEST_F(DBBlockCacheTest, CacheEntryRoleStats) {
   }
 }
 
+namespace {
+
+void DummyFillCache(Cache& cache, size_t entry_size,
+                    std::vector<CacheHandleGuard<void>>& handles) {
+  // fprintf(stderr, "Entry size: %zu\n", entry_size);
+  handles.clear();
+  cache.EraseUnRefEntries();
+  void* fake_value = &cache;
+  size_t capacity = cache.GetCapacity();
+  OffsetableCacheKey ck{"abc", "abc", 42};
+  for (size_t my_usage = 0; my_usage < capacity;) {
+    size_t charge = std::min(entry_size, capacity - my_usage);
+    Cache::Handle* handle;
+    Status st = cache.Insert(ck.WithOffset(my_usage).AsSlice(), fake_value,
+                             charge, /*deleter*/ nullptr, &handle);
+    ASSERT_OK(st);
+    handles.emplace_back(&cache, handle);
+    my_usage += charge;
+  }
+}
+
+class CountingLogger : public Logger {
+ public:
+  ~CountingLogger() override {}
+  using Logger::Logv;
+  void Logv(const InfoLogLevel log_level, const char* format,
+            va_list /*ap*/) override {
+    if (std::strstr(format, "HyperClockCache") == nullptr) {
+      // Not a match
+      return;
+    }
+    // static StderrLogger debug;
+    // debug.Logv(log_level, format, ap);
+    if (log_level == InfoLogLevel::INFO_LEVEL) {
+      ++info_count_;
+    } else if (log_level == InfoLogLevel::WARN_LEVEL) {
+      ++warn_count_;
+    } else if (log_level == InfoLogLevel::ERROR_LEVEL) {
+      ++error_count_;
+    }
+  }
+
+  std::array<int, 3> PopCounts() {
+    std::array<int, 3> rv{{info_count_, warn_count_, error_count_}};
+    info_count_ = warn_count_ = error_count_ = 0;
+    return rv;
+  }
+
+ private:
+  int info_count_{};
+  int warn_count_{};
+  int error_count_{};
+};
+
+}  // namespace
+
+TEST_F(DBBlockCacheTest, HyperClockCacheReportProblems) {
+  size_t capacity = 1024 * 1024;
+  size_t value_size_est = 8 * 1024;
+  HyperClockCacheOptions hcc_opts{capacity, value_size_est};
+  hcc_opts.num_shard_bits = 2;  // 4 shards
+  hcc_opts.metadata_charge_policy = kDontChargeCacheMetadata;
+  std::shared_ptr<Cache> cache = hcc_opts.MakeSharedCache();
+  std::shared_ptr<CountingLogger> logger = std::make_shared<CountingLogger>();
+
+  auto table_options = GetTableOptions();
+  auto options = GetOptions(table_options);
+  table_options.block_cache = cache;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  options.info_log = logger;
+  // Going to sample more directly
+  options.stats_dump_period_sec = 0;
+  Reopen(options);
+
+  std::vector<CacheHandleGuard<void>> handles;
+
+  // Clear anything from DB startup
+  logger->PopCounts();
+
+  // Fill cache based on expected size and check that when we
+  // don't report anything relevant in periodic stats dump
+  DummyFillCache(*cache, value_size_est, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{0, 0, 0}}));
+
+  // Same, within reasonable bounds
+  DummyFillCache(*cache, value_size_est - value_size_est / 4, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{0, 0, 0}}));
+
+  DummyFillCache(*cache, value_size_est + value_size_est / 3, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{0, 0, 0}}));
+
+  // Estimate too high (value size too low) eventually reports ERROR
+  DummyFillCache(*cache, value_size_est / 2, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{0, 1, 0}}));
+
+  DummyFillCache(*cache, value_size_est / 3, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{0, 0, 1}}));
+
+  // Estimate too low (value size too high) starts with INFO
+  // and is only WARNING in the worst case
+  DummyFillCache(*cache, value_size_est * 2, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{1, 0, 0}}));
+
+  DummyFillCache(*cache, value_size_est * 3, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{0, 1, 0}}));
+
+  DummyFillCache(*cache, value_size_est * 20, handles);
+  dbfull()->DumpStats();
+  EXPECT_EQ(logger->PopCounts(), (std::array<int, 3>{{0, 1, 0}}));
+}
+
 #endif  // ROCKSDB_LITE
 
 class DBBlockCacheKeyTest
diff --git a/db/db_impl/db_impl.cc b/db/db_impl/db_impl.cc
index 6fe5bf01ba..d34d7cfb25 100644
--- a/db/db_impl/db_impl.cc
+++ b/db/db_impl/db_impl.cc
@@ -1059,16 +1059,31 @@ void DBImpl::DumpStats() {
     return;
   }
 
+  // Also probe block cache(s) for problems, dump to info log
+  UnorderedSet<Cache*> probed_caches;
   TEST_SYNC_POINT("DBImpl::DumpStats:StartRunning");
   {
     InstrumentedMutexLock l(&mutex_);
     for (auto cfd : versions_->GetRefedColumnFamilySet()) {
-      if (cfd->initialized()) {
-        // Release DB mutex for gathering cache entry stats. Pass over all
-        // column families for this first so that other stats are dumped
-        // near-atomically.
-        InstrumentedMutexUnlock u(&mutex_);
-        cfd->internal_stats()->CollectCacheEntryStats(/*foreground=*/false);
+      if (!cfd->initialized()) {
+        continue;
+      }
+
+      // Release DB mutex for gathering cache entry stats. Pass over all
+      // column families for this first so that other stats are dumped
+      // near-atomically.
+      InstrumentedMutexUnlock u(&mutex_);
+      cfd->internal_stats()->CollectCacheEntryStats(/*foreground=*/false);
+
+      // Probe block cache for problems (if not already via another CF)
+      if (immutable_db_options_.info_log) {
+        auto* table_factory = cfd->ioptions()->table_factory.get();
+        assert(table_factory != nullptr);
+        Cache* cache =
+            table_factory->GetOptions<Cache>(TableFactory::kBlockCacheOpts());
+        if (cache && probed_caches.insert(cache).second) {
+          cache->ReportProblems(immutable_db_options_.info_log);
+        }
       }
     }
 
diff --git a/include/rocksdb/cache.h b/include/rocksdb/cache.h
index c3733fb4fb..575d276b58 100644
--- a/include/rocksdb/cache.h
+++ b/include/rocksdb/cache.h
@@ -37,6 +37,7 @@ namespace ROCKSDB_NAMESPACE {
 
 class Cache;
 struct ConfigOptions;
+class Logger;
 class SecondaryCache;
 
 // Classifications of block cache entries.
@@ -723,6 +724,13 @@ class Cache {
 
   virtual std::string GetPrintableOptions() const { return ""; }
 
+  // Check for any warnings or errors in the operation of the cache and
+  // report them to the logger. This is intended only to be called
+  // periodically so does not need to be very efficient. (Obscure calling
+  // conventions for Logger inherited from env.h)
+  virtual void ReportProblems(
+      const std::shared_ptr<Logger>& /*info_log*/) const {}
+
   MemoryAllocator* memory_allocator() const { return memory_allocator_.get(); }
 
   // EXPERIMENTAL
diff --git a/logging/logging.h b/logging/logging.h
index e7f4f7776c..0fa882a786 100644
--- a/logging/logging.h
+++ b/logging/logging.h
@@ -28,30 +28,24 @@ inline const char* RocksLogShorterFileName(const char* file) {
 #define ROCKS_LOG_HEADER(LGR, FMT, ...) \
   ROCKSDB_NAMESPACE::Log(InfoLogLevel::HEADER_LEVEL, LGR, FMT, ##__VA_ARGS__)
 
-#define ROCKS_LOG_DEBUG(LGR, FMT, ...)                     \
-  ROCKSDB_NAMESPACE::Log(InfoLogLevel::DEBUG_LEVEL, LGR,   \
-                         ROCKS_LOG_PREPEND_FILE_LINE(FMT), \
+#define ROCKS_LOG_AT_LEVEL(LGR, LVL, FMT, ...)                           \
+  ROCKSDB_NAMESPACE::Log((LVL), (LGR), ROCKS_LOG_PREPEND_FILE_LINE(FMT), \
                          RocksLogShorterFileName(__FILE__), ##__VA_ARGS__)
 
-#define ROCKS_LOG_INFO(LGR, FMT, ...)                      \
-  ROCKSDB_NAMESPACE::Log(InfoLogLevel::INFO_LEVEL, LGR,    \
-                         ROCKS_LOG_PREPEND_FILE_LINE(FMT), \
-                         RocksLogShorterFileName(__FILE__), ##__VA_ARGS__)
+#define ROCKS_LOG_DEBUG(LGR, FMT, ...) \
+  ROCKS_LOG_AT_LEVEL((LGR), InfoLogLevel::DEBUG_LEVEL, FMT, ##__VA_ARGS__)
 
-#define ROCKS_LOG_WARN(LGR, FMT, ...)                      \
-  ROCKSDB_NAMESPACE::Log(InfoLogLevel::WARN_LEVEL, LGR,    \
-                         ROCKS_LOG_PREPEND_FILE_LINE(FMT), \
-                         RocksLogShorterFileName(__FILE__), ##__VA_ARGS__)
+#define ROCKS_LOG_INFO(LGR, FMT, ...) \
+  ROCKS_LOG_AT_LEVEL((LGR), InfoLogLevel::INFO_LEVEL, FMT, ##__VA_ARGS__)
 
-#define ROCKS_LOG_ERROR(LGR, FMT, ...)                     \
-  ROCKSDB_NAMESPACE::Log(InfoLogLevel::ERROR_LEVEL, LGR,   \
-                         ROCKS_LOG_PREPEND_FILE_LINE(FMT), \
-                         RocksLogShorterFileName(__FILE__), ##__VA_ARGS__)
+#define ROCKS_LOG_WARN(LGR, FMT, ...) \
+  ROCKS_LOG_AT_LEVEL((LGR), InfoLogLevel::WARN_LEVEL, FMT, ##__VA_ARGS__)
 
-#define ROCKS_LOG_FATAL(LGR, FMT, ...)                     \
-  ROCKSDB_NAMESPACE::Log(InfoLogLevel::FATAL_LEVEL, LGR,   \
-                         ROCKS_LOG_PREPEND_FILE_LINE(FMT), \
-                         RocksLogShorterFileName(__FILE__), ##__VA_ARGS__)
+#define ROCKS_LOG_ERROR(LGR, FMT, ...) \
+  ROCKS_LOG_AT_LEVEL((LGR), InfoLogLevel::ERROR_LEVEL, FMT, ##__VA_ARGS__)
+
+#define ROCKS_LOG_FATAL(LGR, FMT, ...) \
+  ROCKS_LOG_AT_LEVEL((LGR), InfoLogLevel::FATAL_LEVEL, FMT, ##__VA_ARGS__)
 
 #define ROCKS_LOG_BUFFER(LOG_BUF, FMT, ...)                                 \
   ROCKSDB_NAMESPACE::LogToBuffer(LOG_BUF, ROCKS_LOG_PREPEND_FILE_LINE(FMT), \