KVStore: More metrics for Prehandling (pingcap#9131) (pingcap#213)

Signed-off-by: CalvinNeo <[email protected]>

Author: CalvinNeo

Diff for: dbms/src/Common/TiFlashMetrics.h

@@ -424,6 +424,10 @@ namespace DB
       F(type_total, {{"type", "total"}}, ExpBucketsWithRange{0.2, 4, 300}),                                                         \
       F(type_queue_stage, {{"type", "queue_stage"}}, ExpBucketsWithRange{0.2, 4, 300}),                                             \
       F(type_phase1_total, {{"type", "phase1_total"}}, ExpBucketsWithRange{0.2, 4, 300}))                                           \
+    M(tiflash_raft_command_throughput,                                                                                              \
+      "",                                                                                                                           \
+      Histogram,                                                                                                                    \
+      F(type_prehandle_snapshot, {{"type", "prehandle_snapshot"}}, ExpBuckets{128, 2, 11}))                                         \
     M(tiflash_raft_command_duration_seconds,                                                                                        \
       "Bucketed histogram of some raft command: apply snapshot and ingest SST",                                                     \
       Histogram, /* these command usually cost several seconds, increase the start bucket to 50ms */                                \
@@ -484,6 +488,7 @@ namespace DB
       F(type_flush_log_gap, {{"type", "flush_log_gap"}}),                                                                           \
       F(type_flush_size, {{"type", "flush_size"}}),                                                                                 \
       F(type_flush_rowcount, {{"type", "flush_rowcount"}}),                                                                         \
+      F(type_prehandle, {{"type", "prehandle"}}),                                                                                   \
       F(type_flush_eager_gc, {{"type", "flush_eager_gc"}}))                                                                         \
     M(tiflash_raft_raft_frequent_events_count,                                                                                      \
       "Raft frequent event counter",                                                                                                \

Diff for: dbms/src/Storages/KVStore/MultiRaft/PrehandleSnapshot.cpp

@@ -138,6 +138,7 @@ static inline std::tuple<ReadFromStreamResult, PrehandleResult> executeTransform
         trace.releaseSubtaskResources(region_id, split_id);
         CurrentMetrics::sub(CurrentMetrics::RaftNumPrehandlingSubTasks);
     });
+    Stopwatch sw;
     LOG_INFO(
         log,
         "Add prehandle task split_id={} limit={}",
@@ -198,6 +199,10 @@ static inline std::tuple<ReadFromStreamResult, PrehandleResult> executeTransform
             stream->cancel();
             res = ReadFromStreamResult{.error = ReadFromStreamError::Aborted, .extra_msg = "", .region = new_region};
         }
+        auto keys_per_second = (sst_stream->getProcessKeys().write_cf + sst_stream->getProcessKeys().lock_cf
+                                + sst_stream->getProcessKeys().write_cf)
+            * 1.0 / sw.elapsedSeconds();
+        GET_METRIC(tiflash_raft_command_throughput, type_prehandle_snapshot).Observe(keys_per_second);
         return std::make_pair(
             std::move(res),
             PrehandleResult{
@@ -252,6 +257,7 @@ PrehandleResult KVStore::preHandleSnapshotToFiles(
     std::optional<uint64_t> deadline_index,
     TMTContext & tmt)
 {
+    GET_METRIC(tiflash_raft_raft_events_count, type_prehandle).Increment();
     new_region->beforePrehandleSnapshot(new_region->id(), deadline_index);
 
     ongoing_prehandle_task_count.fetch_add(1);