coprocessor: add query digest tracing in tikv slow query (tikv#16172)

ref tikv#15513

coprocessor: add query digest tracing in tikv slow query

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

Author: nolouch

src/coprocessor/tracker.rs

@@ -6,8 +6,10 @@ use ::tracker::{get_tls_tracker_token, with_tls_tracker};
 use engine_traits::{PerfContext, PerfContextExt, PerfContextKind};
 use kvproto::{kvrpcpb, kvrpcpb::ScanDetailV2};
 use pd_client::BucketMeta;
+use protobuf::Message;
 use tikv_kv::Engine;
 use tikv_util::time::{self, Duration, Instant};
+use tipb::ResourceGroupTag;
 use txn_types::Key;
 
 use super::metrics::*;
@@ -266,9 +268,14 @@ impl<E: Engine> Tracker<E> {
 
             let source_stmt = self.req_ctx.context.get_source_stmt();
             with_tls_tracker(|tracker| {
+                let mut req_tag = ResourceGroupTag::new();
+                req_tag
+                    .merge_from_bytes(&tracker.req_info.resource_group_tag)
+                    .unwrap_or_default();
                 info!(#"slow_log", "slow-query";
                     "connection_id" => source_stmt.get_connection_id(),
                     "session_alias" => source_stmt.get_session_alias(),
+                    "query_digest" => hex::encode(req_tag.get_sql_digest()),
                     "region_id" => &self.req_ctx.context.get_region_id(),
                     "remote_host" => &self.req_ctx.peer,
                     "total_lifetime" => ?self.req_lifetime,