From fa0190f88523476b3dfb6d57554abae02547e9a6 Mon Sep 17 00:00:00 2001
From: Qiaolin Yu <liin1211@outlook.com>
Date: Wed, 10 Jan 2024 14:02:14 -0800
Subject: [PATCH] Block cache analyzer: Calculate miss ratio for each caller
 (#10823)

Summary:
Currently, when `block_cache_trace_analyzer` analyzes the cache miss ratio, it only analyzes the total miss ratio.

But it seems also important to analyze the cache miss ratio of each caller. To achieve this, we can calculate and print the miss ratio of each caller in the analyzer.

## Before modification
```
Running for 1 seconds: Processed 85732 records/second. Trace duration 58 seconds. Observed miss ratio 7.97
```

## After modification
```
Running for 1 seconds: Processed 85732 records/second. Trace duration 58 seconds. Observed miss ratio 7.97
Caller Get: Observed miss ratio 6.31
Caller Iterator: Observed miss ratio 11.86
***************************************************************
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10823

Reviewed By: ajkr

Differential Revision: D52632764

Pulled By: hx235

fbshipit-source-id: 40994d6039b73dc38fe78ea1b4adce187bb98909
---
 .../block_cache_trace_analyzer.cc               | 17 +++++++++++++++++
 .../block_cache_trace_analyzer.h                |  1 +
 2 files changed, 18 insertions(+)

diff --git a/tools/block_cache_analyzer/block_cache_trace_analyzer.cc b/tools/block_cache_analyzer/block_cache_trace_analyzer.cc
index e6473191df..38532660b0 100644
--- a/tools/block_cache_analyzer/block_cache_trace_analyzer.cc
+++ b/tools/block_cache_analyzer/block_cache_trace_analyzer.cc
@@ -1571,6 +1571,10 @@ Status BlockCacheTraceAnalyzer::Analyze() {
     miss_ratio_stats_.UpdateMetrics(access.access_timestamp,
                                     is_user_access(access.caller),
                                     !access.is_cache_hit);
+    caller_miss_ratio_stats_map_[access.caller].UpdateMetrics(
+        access.access_timestamp, is_user_access(access.caller),
+        !access.is_cache_hit);
+
     if (cache_simulator_) {
       cache_simulator_->Access(access);
     }
@@ -1586,6 +1590,14 @@ Status BlockCacheTraceAnalyzer::Analyze() {
               " seconds. Observed miss ratio %.2f\n",
               duration, duration > 0 ? access_sequence_number_ / duration : 0,
               trace_duration, miss_ratio_stats_.miss_ratio());
+
+      for (const auto& caller : caller_miss_ratio_stats_map_) {
+        fprintf(stdout, "Caller %s: Observed miss ratio %.2f\n",
+                caller_to_string(caller.first).c_str(),
+                caller.second.miss_ratio());
+      }
+      print_break_lines(/*num_break_lines=*/1);
+
       time_interval++;
     }
   }
@@ -1599,6 +1611,11 @@ Status BlockCacheTraceAnalyzer::Analyze() {
           " seconds. Observed miss ratio %.2f\n",
           duration, duration > 0 ? access_sequence_number_ / duration : 0,
           trace_duration, miss_ratio_stats_.miss_ratio());
+  for (const auto& caller : caller_miss_ratio_stats_map_) {
+    fprintf(stdout, "Caller %s: Observed miss ratio %.2f\n",
+            caller_to_string(caller.first).c_str(), caller.second.miss_ratio());
+  }
+  print_break_lines(/*num_break_lines=*/1);
   return s;
 }
 
diff --git a/tools/block_cache_analyzer/block_cache_trace_analyzer.h b/tools/block_cache_analyzer/block_cache_trace_analyzer.h
index 2f1ebd139b..a7842d1d4a 100644
--- a/tools/block_cache_analyzer/block_cache_trace_analyzer.h
+++ b/tools/block_cache_analyzer/block_cache_trace_analyzer.h
@@ -387,6 +387,7 @@ class BlockCacheTraceAnalyzer {
   uint64_t trace_start_timestamp_in_seconds_ = 0;
   uint64_t trace_end_timestamp_in_seconds_ = 0;
   MissRatioStats miss_ratio_stats_;
+  std::map<TableReaderCaller, MissRatioStats> caller_miss_ratio_stats_map_;
   uint64_t unique_block_id_ = 1;
   uint64_t unique_get_key_id_ = 1;
   BlockCacheHumanReadableTraceWriter human_readable_trace_writer_;