Remove core metrics (#6990)

* remove core metrics

* remove metrics from package.swift

CHANGELOG.md

@@ -29,6 +29,7 @@
 ### Internals
 * Update History Command tool to work with realms with fileformat v23 ([PR #6970](https://github.com/realm/realm-core/pull/6970))
 * Don't edit the ObjectStore target to enable the libuv scheduler in tests, just register the factory instead. ([PR #6699](https://github.com/realm/realm-core/pull/6699))
+* Removed the core metrics which were unused. ([PR 6990](https://github.com/realm/realm-core/pull/6990))
 
 ----------------------------------------------
 

CMakeLists.txt

@@ -254,7 +254,6 @@ if(NOT EMSCRIPTEN)
 endif()
 option(REALM_ENABLE_MEMDEBUG "Add additional memory checks" OFF)
 option(REALM_VALGRIND "Tell the test suite we are running with valgrind" OFF)
-option(REALM_METRICS "Enable various metric tracking" ON)
 option(REALM_SYNC_MULTIPLEXING "Enables/disables sync session multiplexing by default" ON)
 set(REALM_MAX_BPNODE_SIZE "1000" CACHE STRING "Max B+ tree node size.")
 option(REALM_ENABLE_GEOSPATIAL "Enable geospatial types and queries." ON)

Package.swift

@@ -403,7 +403,6 @@ let package = Package(
                 "realm/CMakeLists.txt",
                 "realm/exec",
                 "realm/geospatial.cpp",
-                "realm/metrics",
                 "realm/object-store/CMakeLists.txt",
                 "realm/object-store/c_api",
                 "realm/object-store/impl/epoll",
@@ -451,7 +450,6 @@ let package = Package(
                 "external",
                 "realm/CMakeLists.txt",
                 "realm/exec",
-                "realm/metrics",
                 "realm/object-store",
                 "realm/parser",
                 "realm/sync/CMakeLists.txt",

src/realm/CMakeLists.txt

@@ -249,11 +249,6 @@ set(REALM_INSTALL_HEADERS
     util/to_string.hpp
     util/type_traits.hpp
     util/uri.hpp
-
-    metrics/metrics.hpp
-    metrics/metric_timer.hpp
-    metrics/query_info.hpp
-    metrics/transaction_info.hpp
 ) # REALM_INSTALL_HEADERS
 
 set(REALM_NOINST_HEADERS
@@ -279,12 +274,6 @@ set(REALM_NOINST_HEADERS
     util/value_reset_guard.hpp
 ) # REALM_NOINST_HEADERS
 
-list(APPEND REALM_SOURCES
-    metrics/metrics.cpp
-    metrics/metric_timer.cpp
-    metrics/query_info.cpp
-    metrics/transaction_info.cpp)
-
 if(NOT MSVC)
     list(APPEND REALM_SOURCES util/interprocess_mutex.cpp)
 endif()

src/realm/db.cpp

@@ -57,7 +57,6 @@
 
 
 using namespace realm;
-using namespace realm::metrics;
 using namespace realm::util;
 using Durability = DBOptions::Durability;
 
@@ -1443,11 +1442,6 @@ void DB::open(const std::string& path, bool no_create_file, const DBOptions& opt
         close();
         throw;
     }
-#if REALM_METRICS
-    if (options.enable_metrics) {
-        m_metrics = std::make_shared<Metrics>(options.metrics_buffer_size);
-    }
-#endif // REALM_METRICS
     m_alloc.set_read_only(true);
 }
 
@@ -1534,11 +1528,6 @@ void DB::open(Replication& repl, const DBOptions options)
 
     m_file_format_version = target_file_format_version;
 
-#if REALM_METRICS
-    if (options.enable_metrics) {
-        m_metrics = std::make_shared<Metrics>(options.metrics_buffer_size);
-    }
-#endif // REALM_METRICS
     m_info = info;
     m_alloc.set_read_only(true);
 }
@@ -2483,9 +2472,6 @@ void DB::low_level_commit(uint_fast64_t new_version, Transaction& transaction, b
     auto live_versions = top_refs.size();
     // Do the actual commit
     REALM_ASSERT(oldest_version <= new_version);
-#if REALM_METRICS
-    transaction.update_num_objects();
-#endif // REALM_METRICS
 
     GroupWriter out(transaction, Durability(info->durability), m_marker_observer.get()); // Throws
     out.set_versions(new_version, top_refs, any_new_unreachables);

src/realm/db.hpp

@@ -24,7 +24,6 @@
 #include <realm/handover_defs.hpp>
 #include <realm/impl/changeset_input_stream.hpp>
 #include <realm/impl/transact_log.hpp>
-#include <realm/metrics/metrics.hpp>
 #include <realm/replication.hpp>
 #include <realm/util/checked_mutex.hpp>
 #include <realm/util/features.h>
@@ -391,10 +390,6 @@ class DB : public std::enable_shared_from_this<DB> {
     /// On the importing side, the top-level accessor being created during
     /// import takes ownership of all other accessors (if any) being created as
     /// part of the import.
-    std::shared_ptr<metrics::Metrics> get_metrics()
-    {
-        return m_metrics;
-    }
 
     // Try to grab an exclusive lock of the given realm path's lock file. If the lock
     // can be acquired, the callback will be executed with the lock and then return true.
@@ -507,7 +502,6 @@ class DB : public std::enable_shared_from_this<DB> {
     util::InterprocessCondVar m_new_commit_available;
     util::InterprocessCondVar m_pick_next_writer;
     std::function<void(int, int)> m_upgrade_callback;
-    std::shared_ptr<metrics::Metrics> m_metrics;
     std::unique_ptr<AsyncCommitHelper> m_commit_helper;
     std::shared_ptr<util::Logger> m_logger;
     bool m_is_sync_agent = false;

src/realm/db_options.hpp

@@ -80,14 +80,6 @@ struct DBOptions {
     /// This string should include a trailing slash '/'.
     std::string temp_dir = sys_tmp_dir;
 
-    /// Controls the feature of collecting various metrics to the DB.
-    /// A prerequisite is compiling with REALM_METRICS=ON.
-    bool enable_metrics = false;
-
-    /// The maximum number of entries stored by the metrics (if enabled). If this number
-    /// is exceeded without being consumed, only the most recent entries will be stored.
-    size_t metrics_buffer_size = 10000;
-
     /// is_immutable should be set to true if run from a read-only file system.
     /// this will prevent the DB from making any writes, also disabling the creation
     /// of write transactions.

src/realm/group.cpp

@@ -76,7 +76,6 @@ Group::Group(const std::string& file_path, const char* encryption_key)
     , m_top(m_alloc)
     , m_tables(m_alloc)
     , m_table_names(m_alloc)
-    , m_total_rows(0)
 {
     init_array_parents();
 
@@ -99,7 +98,6 @@ Group::Group(BinaryData buffer, bool take_ownership)
     , m_top(m_alloc)
     , m_tables(m_alloc)
     , m_table_names(m_alloc)
-    , m_total_rows(0)
 {
     REALM_ASSERT(buffer.data());
 
@@ -118,7 +116,6 @@ Group::Group(SlabAlloc* alloc) noexcept
     m_top(m_alloc)
     , m_tables(m_alloc)
     , m_table_names(m_alloc)
-    , m_total_rows(0)
 {
     init_array_parents();
 }
@@ -560,9 +557,6 @@ void Group::attach(ref_type top_ref, bool writable, bool create_group_when_missi
     while (m_table_accessors.size() < sz) {
         m_table_accessors.emplace_back();
     }
-#if REALM_METRICS
-    update_num_objects();
-#endif // REALM_METRICS
 }
 
 
@@ -578,23 +572,6 @@ void Group::detach() noexcept
     m_attached = false;
 }
 
-void Group::update_num_objects()
-{
-#if REALM_METRICS
-    if (m_metrics) {
-        // This is quite invasive and completely defeats the lazy loading mechanism
-        // where table accessors are only instantiated on demand, because they are all created here.
-
-        m_total_rows = 0;
-        auto keys = get_table_keys();
-        for (auto key : keys) {
-            ConstTableRef t = get_table(key);
-            m_total_rows += t->size();
-        }
-    }
-#endif // REALM_METRICS
-}
-
 void Group::attach_shared(ref_type new_top_ref, size_t new_file_size, bool writable, VersionID version)
 {
     REALM_ASSERT_3(new_top_ref, <, new_file_size);

src/realm/group.hpp

@@ -31,7 +31,6 @@
 #include <realm/exceptions.hpp>
 #include <realm/impl/cont_transact_hist.hpp>
 #include <realm/impl/output_stream.hpp>
-#include <realm/metrics/metrics.hpp>
 #include <realm/table.hpp>
 #include <realm/util/features.h>
 #include <realm/util/input_stream.hpp>
@@ -615,9 +614,7 @@ class Group : public ArrayParent {
 
     util::UniqueFunction<void(const CascadeNotification&)> m_notify_handler;
     util::UniqueFunction<void()> m_schema_change_handler;
-    std::shared_ptr<metrics::Metrics> m_metrics;
     std::vector<ToDeleteRef> m_objects_to_delete;
-    size_t m_total_rows;
 
     Group(SlabAlloc* alloc) noexcept;
     void init_array_parents() noexcept;
@@ -690,9 +687,6 @@ class Group : public ArrayParent {
     void write(util::File& file, const char* encryption_key, uint_fast64_t version_number, TableWriter& writer) const;
     void write(std::ostream&, bool pad, uint_fast64_t version_numer, TableWriter& writer) const;
 
-    std::shared_ptr<metrics::Metrics> get_metrics() const noexcept;
-    void set_metrics(std::shared_ptr<metrics::Metrics> other) noexcept;
-    void update_num_objects();
     /// Memory mappings must have been updated to reflect any growth in filesize before
     /// calling advance_transact()
     void advance_transact(ref_type new_top_ref, util::InputStream*, bool writable);
@@ -837,8 +831,6 @@ class Group : public ArrayParent {
     friend class GroupCommitter;
     friend class DB;
     friend class _impl::GroupFriend;
-    friend class metrics::QueryInfo;
-    friend class metrics::Metrics;
     friend class Transaction;
     friend class TableKeyIterator;
     friend class CascadeState;
@@ -1175,16 +1167,6 @@ inline void Group::reset_free_space_tracking()
     m_alloc.reset_free_space_tracking(); // Throws
 }
 
-inline std::shared_ptr<metrics::Metrics> Group::get_metrics() const noexcept
-{
-    return m_metrics;
-}
-
-inline void Group::set_metrics(std::shared_ptr<metrics::Metrics> shared) noexcept
-{
-    m_metrics = shared;
-}
-
 // The purpose of this class is to give internal access to some, but
 // not all of the non-public parts of the Group class.
 class _impl::GroupFriend {

src/realm/group_writer.cpp

@@ -28,13 +28,11 @@
 #include <realm/disable_sync_to_disk.hpp>
 #include <realm/impl/destroy_guard.hpp>
 #include <realm/impl/simulated_failure.hpp>
-#include <realm/metrics/metric_timer.hpp>
 #include <realm/util/miscellaneous.hpp>
 #include <realm/util/safe_int_ops.hpp>
 
 using namespace realm;
 using namespace realm::util;
-using namespace realm::metrics;
 
 namespace realm {
 class InMemoryWriter : public _impl::ArrayWriterBase {
@@ -647,10 +645,6 @@ void GroupWriter::prepare_evacuation()
 
 ref_type GroupWriter::write_group()
 {
-#if REALM_METRICS
-    std::unique_ptr<MetricTimer> fsync_timer = Metrics::report_write_time(m_group);
-#endif // REALM_METRICS
-
     ALLOC_DBG_COUT("Commit nr " << m_current_version << "   ( from " << m_oldest_reachable_version << " )"
                                 << std::endl);
 
@@ -1409,10 +1403,6 @@ void GroupCommitter::commit(ref_type new_top_ref)
     bool disable_sync = get_disable_sync_to_disk() || m_durability == Durability::Unsafe;
     file_header.m_top_ref[slot_selector] = new_top_ref;
 
-#if REALM_METRICS
-    std::unique_ptr<MetricTimer> fsync_timer = Metrics::report_fsync_time(m_group);
-#endif // REALM_METRICS
-
     // Make sure that that all data relating to the new snapshot is written to
     // stable storage before flipping the slot selector
     window->encryption_write_barrier(&file_header, sizeof file_header);