From c09acb0a06d3cf1a616f9afdaef8936a0f71e9b2 Mon Sep 17 00:00:00 2001
From: zhengyu <zhangzhengyu@selectdb.com>
Date: Tue, 17 Jun 2025 14:25:58 +0800
Subject: [PATCH] [enhancement](cloud) monitor evict size of file cache active
 gc (#51197)

monitor file cache gc, i.e. eviction caused by bad compaction, tablet
meta removal(drop table/partion or rebalance)

Signed-off-by: zhengyu <zhangzhengyu@selectdb.com>
---
 be/src/io/cache/block_file_cache.cpp | 6 ++++++
 be/src/io/cache/block_file_cache.h   | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/be/src/io/cache/block_file_cache.cpp b/be/src/io/cache/block_file_cache.cpp
index c55e9dac76c180..1e16d79dc5c057 100644
--- a/be/src/io/cache/block_file_cache.cpp
+++ b/be/src/io/cache/block_file_cache.cpp
@@ -87,6 +87,10 @@ BlockFileCache::BlockFileCache(const std::string& cache_base_path,
             _cache_base_path.c_str(), "file_cache_ttl_cache_evict_size");
     _total_evict_size_metrics = std::make_shared<bvar::Adder<size_t>>(
             _cache_base_path.c_str(), "file_cache_total_evict_size");
+    _gc_evict_bytes_metrics = std::make_shared<bvar::Adder<size_t>>(_cache_base_path.c_str(),
+                                                                    "file_cache_gc_evict_bytes");
+    _gc_evict_count_metrics = std::make_shared<bvar::Adder<size_t>>(_cache_base_path.c_str(),
+                                                                    "file_cache_gc_evict_count");
 
     _evict_by_time_metrics_matrix[FileCacheType::DISPOSABLE][FileCacheType::NORMAL] =
             std::make_shared<bvar::Adder<size_t>>(_cache_base_path.c_str(),
@@ -1146,6 +1150,8 @@ void BlockFileCache::remove_if_cached_async(const UInt128Wrapper& file_key) {
         std::vector<FileBlockCell*> to_remove;
         if (iter != _files.end()) {
             for (auto& [_, cell] : iter->second) {
+                *_gc_evict_bytes_metrics << cell.size();
+                *_gc_evict_count_metrics << 1;
                 if (cell.releasable()) {
                     to_remove.push_back(&cell);
                 } else {
diff --git a/be/src/io/cache/block_file_cache.h b/be/src/io/cache/block_file_cache.h
index c12b03cc998792..7c046cc162783a 100644
--- a/be/src/io/cache/block_file_cache.h
+++ b/be/src/io/cache/block_file_cache.h
@@ -546,6 +546,8 @@ class BlockFileCache {
     std::shared_ptr<bvar::Status<size_t>> _cur_disposable_queue_cache_size_metrics;
     std::array<std::shared_ptr<bvar::Adder<size_t>>, 4> _queue_evict_size_metrics;
     std::shared_ptr<bvar::Adder<size_t>> _total_evict_size_metrics;
+    std::shared_ptr<bvar::Adder<size_t>> _gc_evict_bytes_metrics;
+    std::shared_ptr<bvar::Adder<size_t>> _gc_evict_count_metrics;
     std::shared_ptr<bvar::Adder<size_t>> _evict_by_time_metrics_matrix[4][4];
     std::shared_ptr<bvar::Adder<size_t>> _evict_by_size_metrics_matrix[4][4];
     std::shared_ptr<bvar::Adder<size_t>> _evict_by_self_lru_metrics_matrix[4];