From fc94b2c2654ed470bdb1cc3b6dcf2d78abf820da Mon Sep 17 00:00:00 2001
From: Roman Gershman <roman@dragonflydb.io>
Date: Wed, 29 Jan 2025 19:08:41 +0200
Subject: [PATCH] chore: add more logs to the op_manager code (#4527)

Signed-off-by: Roman Gershman <roman@dragonflydb.io>
---
 .github/workflows/ci.yml              |  2 +-
 src/server/tiering/common.h           |  4 ++++
 src/server/tiering/op_manager.cc      | 13 +++++++++++++
 src/server/tiering/op_manager_test.cc |  1 +
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 572fea4c2..935d94bcb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -171,7 +171,7 @@ jobs:
         run: |
           cd ${GITHUB_WORKSPACE}/build
           echo Run ctest -V -L DFLY
-          GLOG_alsologtostderr=1 GLOG_vmodule=rdb_load=1,rdb_save=1,snapshot=1 \
+          GLOG_alsologtostderr=1 GLOG_vmodule=rdb_load=1,rdb_save=1,snapshot=1,op_manager=1,op_manager_test=1 \
           FLAGS_fiber_safety_margin=4096 FLAGS_list_experimental_v2=true timeout 20m ctest -V -L DFLY
 
           echo "Running tests with --force_epoll"
diff --git a/src/server/tiering/common.h b/src/server/tiering/common.h
index 13de4fe99..778391d2d 100644
--- a/src/server/tiering/common.h
+++ b/src/server/tiering/common.h
@@ -42,6 +42,10 @@ struct DiskSegment {
   }
 
   size_t offset = 0, length = 0;
+
+  friend std::ostream& operator<<(std::ostream& os, const DiskSegment& ds) {
+    return os << "[" << ds.offset << ", " << ds.length << "]";
+  }
 };
 
 };  // namespace dfly::tiering
diff --git a/src/server/tiering/op_manager.cc b/src/server/tiering/op_manager.cc
index 36d9c2360..5e727d67c 100644
--- a/src/server/tiering/op_manager.cc
+++ b/src/server/tiering/op_manager.cc
@@ -28,6 +28,16 @@ OpManager::EntryId Borrowed(const OpManager::OwnedEntryId& id) {
   return std::visit([](const auto& v) -> OpManager::EntryId { return v; }, id);
 }
 
+std::ostream& operator<<(std::ostream& os, const OpManager::EntryId& id) {
+  if (const auto* i = std::get_if<unsigned>(&id); i) {
+    return os << *i;
+  } else {
+    const auto& key = std::get<OpManager::KeyRef>(id);
+    return os << "(" << key.first << ':' << key.second << ")";
+  }
+  return os;
+}
+
 }  // namespace
 
 OpManager::OpManager(size_t max_size) : storage_{max_size} {
@@ -115,7 +125,10 @@ void OpManager::ProcessStashed(EntryId id, unsigned version,
     NotifyStashed(id, segment);
   } else if (segment) {
     // Throw away the value because it's no longer up-to-date even if no error occured
+    VLOG(1) << "Releasing segment " << *segment << ", id: " << id;
     storage_.MarkAsFree(*segment);
+  } else {
+    LOG(ERROR) << "Stash failed with error " << segment.error();
   }
 }
 
diff --git a/src/server/tiering/op_manager_test.cc b/src/server/tiering/op_manager_test.cc
index 9eb0c8641..dc3f00d50 100644
--- a/src/server/tiering/op_manager_test.cc
+++ b/src/server/tiering/op_manager_test.cc
@@ -54,6 +54,7 @@ struct OpManagerTest : PoolTestBase, OpManager {
   }
 
   void NotifyStashed(EntryId id, const io::Result<DiskSegment>& segment) override {
+    VLOG(1) << std::get<0>(id) << " stashed";
     ASSERT_TRUE(segment);
     auto [it, inserted] = stashed_.emplace(id, *segment);
     ASSERT_TRUE(inserted);