server, sql: surface session txnCount, txn fingerprints, active time

Partially addresses cockroachdb#74257.

Previously, the status server did not provide session details such as
total number of transactions executed, transaction fingerprint
IDs, and total active time. This change adds the aforementioned session
details to the `serverpb.Session` struct.

To track recently executed transaction fingerprint IDs, a FIFO cache
`TxnFingerprintIDCache` is introduced with its corresponding cluster
setting `TxnFingerprintIDBufferCapacity` to control the capacity. The
default capacity is set at 100 fingerprints.

The total number of transactions executed is filled using the existing
`txnCounter` from the `extraTxnState` in `connExecutor`. The total active
time is calculated by introducing a `timeutil.StopWatch` to the connection
executor, which is started and stopped when a transaction is started and
finished respectively.

Release note (api change): the `serverpb.Session` struct now has three
new fields: number of transactions executed, transaction fingerprint
IDs, and total active time.

docs/generated/http/full.md

@@ -2111,6 +2111,9 @@ Session represents one SQL session.
 | last_active_query_no_constants | [string](#cockroach.server.serverpb.ListSessionsResponse-string) |  | The SQL statement fingerprint of the last query executed on this session, compatible with StatementStatisticsKey. | [reserved](#support-status) |
 | status | [Session.Status](#cockroach.server.serverpb.ListSessionsResponse-cockroach.server.serverpb.Session.Status) |  | The session's status. | [reserved](#support-status) |
 | end | [google.protobuf.Timestamp](#cockroach.server.serverpb.ListSessionsResponse-google.protobuf.Timestamp) |  | Timestamp of session's end. | [reserved](#support-status) |
+| num_txns_executed | [int32](#cockroach.server.serverpb.ListSessionsResponse-int32) |  | Count of the number of transactions that have been opened on this session. This count includes transactions that are in progress. | [reserved](#support-status) |
+| txn_fingerprint_ids | [uint64](#cockroach.server.serverpb.ListSessionsResponse-uint64) | repeated | List of transaction fingerprint IDs in this session. | [reserved](#support-status) |
+| total_active_time | [google.protobuf.Duration](#cockroach.server.serverpb.ListSessionsResponse-google.protobuf.Duration) |  | The session's total active time. | [reserved](#support-status) |
 
 
 
@@ -2247,6 +2250,9 @@ Session represents one SQL session.
 | last_active_query_no_constants | [string](#cockroach.server.serverpb.ListSessionsResponse-string) |  | The SQL statement fingerprint of the last query executed on this session, compatible with StatementStatisticsKey. | [reserved](#support-status) |
 | status | [Session.Status](#cockroach.server.serverpb.ListSessionsResponse-cockroach.server.serverpb.Session.Status) |  | The session's status. | [reserved](#support-status) |
 | end | [google.protobuf.Timestamp](#cockroach.server.serverpb.ListSessionsResponse-google.protobuf.Timestamp) |  | Timestamp of session's end. | [reserved](#support-status) |
+| num_txns_executed | [int32](#cockroach.server.serverpb.ListSessionsResponse-int32) |  | Count of the number of transactions that have been opened on this session. This count includes transactions that are in progress. | [reserved](#support-status) |
+| txn_fingerprint_ids | [uint64](#cockroach.server.serverpb.ListSessionsResponse-uint64) | repeated | List of transaction fingerprint IDs in this session. | [reserved](#support-status) |
+| total_active_time | [google.protobuf.Duration](#cockroach.server.serverpb.ListSessionsResponse-google.protobuf.Duration) |  | The session's total active time. | [reserved](#support-status) |
 
 
 

docs/generated/settings/settings-for-tenants.txt

@@ -273,6 +273,7 @@ sql.ttl.default_delete_rate_limit	integer	0	default delete rate limit for all TT
 sql.ttl.default_range_concurrency	integer	1	default amount of ranges to process at once during a TTL delete
 sql.ttl.default_select_batch_size	integer	500	default amount of rows to select in a single query during a TTL job
 sql.ttl.job.enabled	boolean	true	whether the TTL job is enabled
+sql.txn_fingerprint_id_cache.capacity	integer	100	the maximum number of txn fingerprint IDs stored
 timeseries.storage.enabled	boolean	true	if set, periodic timeseries data is stored within the cluster; disabling is not recommended unless you are storing the data elsewhere
 timeseries.storage.resolution_10s.ttl	duration	240h0m0s	the maximum age of time series data stored at the 10 second resolution. Data older than this is subject to rollup and deletion.
 timeseries.storage.resolution_30m.ttl	duration	2160h0m0s	the maximum age of time series data stored at the 30 minute resolution. Data older than this is subject to deletion.

docs/generated/settings/settings.html

@@ -204,6 +204,7 @@
 <tr><td><code>sql.ttl.default_range_concurrency</code></td><td>integer</td><td><code>1</code></td><td>default amount of ranges to process at once during a TTL delete</td></tr>
 <tr><td><code>sql.ttl.default_select_batch_size</code></td><td>integer</td><td><code>500</code></td><td>default amount of rows to select in a single query during a TTL job</td></tr>
 <tr><td><code>sql.ttl.job.enabled</code></td><td>boolean</td><td><code>true</code></td><td>whether the TTL job is enabled</td></tr>
+<tr><td><code>sql.txn_fingerprint_id_cache.capacity</code></td><td>integer</td><td><code>100</code></td><td>the maximum number of txn fingerprint IDs stored</td></tr>
 <tr><td><code>timeseries.storage.enabled</code></td><td>boolean</td><td><code>true</code></td><td>if set, periodic timeseries data is stored within the cluster; disabling is not recommended unless you are storing the data elsewhere</td></tr>
 <tr><td><code>timeseries.storage.resolution_10s.ttl</code></td><td>duration</td><td><code>240h0m0s</code></td><td>the maximum age of time series data stored at the 10 second resolution. Data older than this is subject to rollup and deletion.</td></tr>
 <tr><td><code>timeseries.storage.resolution_30m.ttl</code></td><td>duration</td><td><code>2160h0m0s</code></td><td>the maximum age of time series data stored at the 30 minute resolution. Data older than this is subject to deletion.</td></tr>

docs/generated/swagger/spec.json

@@ -773,6 +773,12 @@
       },
       "x-go-package": "github.com/cockroachdb/cockroach/pkg/server/serverpb"
     },
+    "Duration": {
+      "description": "A Duration represents the elapsed time between two instants\nas an int64 nanosecond count. The representation limits the\nlargest representable duration to approximately 290 years.",
+      "type": "integer",
+      "format": "int64",
+      "x-go-package": "time"
+    },
     "EventsResponse": {
       "description": "EventsResponse contains a set of event log entries. This is always limited\nto the latest N entries (N is enforced in the associated endpoint).",
       "type": "object",
@@ -1225,6 +1231,12 @@
         "node_id": {
           "$ref": "#/definitions/NodeID"
         },
+        "num_txns_executed": {
+          "description": "Count of the number of transactions that have been opened on this session.\nThis count includes transactions that are in progress.",
+          "type": "integer",
+          "format": "int32",
+          "x-go-name": "NumTxnsExecuted"
+        },
         "start": {
           "description": "Timestamp of session's start.",
           "type": "string",
@@ -1234,6 +1246,17 @@
         "status": {
           "$ref": "#/definitions/Session_Status"
         },
+        "total_active_time": {
+          "$ref": "#/definitions/Duration"
+        },
+        "txn_fingerprint_ids": {
+          "description": "List of transaction fingerprint IDs in this session.",
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/TransactionFingerprintID"
+          },
+          "x-go-name": "TxnFingerprintIDs"
+        },
         "username": {
           "description": "Username of the user for this session.",
           "type": "string",
@@ -1498,6 +1521,12 @@
       },
       "x-go-package": "github.com/cockroachdb/cockroach/pkg/util/hlc"
     },
+    "TransactionFingerprintID": {
+      "description": "TransactionFingerprintID is the hashed string constructed using the\nindividual statement fingerprint IDs that comprise the transaction.",
+      "type": "integer",
+      "format": "uint64",
+      "x-go-package": "github.com/cockroachdb/cockroach/pkg/roachpb"
+    },
     "TxnInfo": {
       "type": "object",
       "title": "TxnInfo represents an in flight user transaction on some Session.",

pkg/ccl/logictestccl/testdata/logic_test/crdb_internal_tenant

@@ -245,15 +245,15 @@ SELECT  * FROM crdb_internal.cluster_transactions WHERE node_id < 0
 ----
 id  node_id  session_id  start  txn_string  application_name  num_stmts  num_retries  num_auto_retries  last_auto_retry_reason
 
-query ITTTTTTTTTTTTT colnames
+query ITTTTTTTTTTTTTT colnames
 SELECT * FROM crdb_internal.node_sessions WHERE node_id < 0
 ----
-node_id  session_id  user_name  client_address  application_name  active_queries  last_active_query  session_start  oldest_query_start  kv_txn  alloc_bytes  max_alloc_bytes status session_end
+node_id  session_id  user_name  client_address  application_name  active_queries  last_active_query  num_txns_executed  session_start  oldest_query_start  kv_txn  alloc_bytes  max_alloc_bytes status session_end
 
-query ITTTTTTTTTTTTT colnames
+query ITTTTTTTTTTTTTT colnames
 SELECT * FROM crdb_internal.cluster_sessions WHERE node_id < 0
 ----
-node_id  session_id  user_name  client_address  application_name  active_queries  last_active_query  session_start  oldest_query_start  kv_txn  alloc_bytes  max_alloc_bytes status session_end
+node_id  session_id  user_name  client_address  application_name  active_queries  last_active_query  num_txns_executed  session_start  oldest_query_start  kv_txn  alloc_bytes  max_alloc_bytes status session_end
 
 query IIITTTI colnames
 SELECT * FROM crdb_internal.node_contention_events WHERE table_id < 0

pkg/server/serverpb/status.proto

@@ -949,9 +949,11 @@ message Session {
   // Information about the txn in progress on this session. Nil if the
   // session doesn't currently have a transaction.
   TxnInfo active_txn = 12;
+
   // The SQL statement fingerprint of the last query executed on this session,
   // compatible with StatementStatisticsKey.
   string last_active_query_no_constants = 13;
+
   // Enum for sessions status.
   enum Status {
     ACTIVE = 0;
@@ -960,9 +962,23 @@ message Session {
   }
   // The session's status.
   Status status = 14;
+
   // Timestamp of session's end.
   google.protobuf.Timestamp end = 15
       [ (gogoproto.nullable) = true, (gogoproto.stdtime) = true ];
+
+  // Count of the number of transactions that have been opened on this session.
+  // This count includes transactions that are in progress.
+  int32 num_txns_executed = 16;
+
+  // List of transaction fingerprint IDs in this session.
+  repeated uint64 txn_fingerprint_ids = 17 [(gogoproto.customname) = "TxnFingerprintIDs",
+    (gogoproto.customtype) = "github.com/cockroachdb/cockroach/pkg/roachpb.TransactionFingerprintID",
+    (gogoproto.nullable) = false];
+
+  // The session's total active time.
+  google.protobuf.Duration total_active_time = 18 [(gogoproto.nullable) = false,
+    (gogoproto.stdduration) = true];
 }
 
 // An error wrapper object for ListSessionsResponse.

pkg/sql/BUILD.bazel

@@ -226,6 +226,7 @@ go_library(
         "testutils.go",
         "topk.go",
         "truncate.go",
+        "txn_fingerprint_id_cache.go",
         "txn_state.go",
         "type_change.go",
         "unary.go",
@@ -585,6 +586,7 @@ go_test(
         "temporary_schema_test.go",
         "tenant_test.go",
         "trace_test.go",
+        "txn_fingerprint_id_cache_test.go",
         "txn_restart_test.go",
         "txn_state_test.go",
         "type_change_test.go",

pkg/sql/conn_executor.go

@@ -884,6 +884,8 @@ func (s *Server) newConnExecutor(
 		stmtDiagnosticsRecorder:   s.cfg.StmtDiagnosticsRecorder,
 		indexUsageStats:           s.indexUsageStats,
 		txnIDCacheWriter:          s.txnIDCache,
+		totalActiveTimeStopWatch:  timeutil.NewStopWatch(),
+		txnFingerprintIDCache:     NewTxnFingerprintIDCache(s.cfg.Settings, sessionRootMon),
 	}
 
 	ex.state.txnAbortCount = ex.metrics.EngineMetrics.TxnAbortCount
@@ -1489,6 +1491,14 @@ type connExecutor struct {
 	// txnIDCacheWriter is used to write txnidcache.ResolvedTxnID to the
 	// Transaction ID Cache.
 	txnIDCacheWriter txnidcache.Writer
+
+	// txnFingerprintIDCache is used to track the most recent
+	// txnFingerprintIDs executed in this session.
+	txnFingerprintIDCache *TxnFingerprintIDCache
+
+	// totalActiveTimeStopWatch tracks the total active time of the session.
+	// This is defined as the time spent executing transactions and statements.
+	totalActiveTimeStopWatch *timeutil.StopWatch
 }
 
 // ctxHolder contains a connection's context and, while session tracing is
@@ -2865,6 +2875,10 @@ func (ex *connExecutor) txnStateTransitionsApplyWrapper(
 		// Start of the transaction, so no statements were executed earlier.
 		// Bump the txn counter for logging.
 		ex.extraTxnState.txnCounter++
+
+		// Session is considered active when executing a transaction.
+		ex.totalActiveTimeStopWatch.Start()
+
 		if !ex.server.cfg.Codec.ForSystemTenant() {
 			// Update the leased descriptor collection with the current sqlliveness.Session.
 			// This is required in the multi-tenant environment to update the transaction
@@ -3120,19 +3134,28 @@ func (ex *connExecutor) serialize() serverpb.Session {
 		remoteStr = sd.RemoteAddr.String()
 	}
 
+	txnFingerprintIDs := ex.txnFingerprintIDCache.GetAllTxnFingerprintIDs()
+	sessionActiveTime := ex.totalActiveTimeStopWatch.Elapsed()
+	if startedAt, started := ex.totalActiveTimeStopWatch.LastStartedAt(); started {
+		sessionActiveTime = time.Duration(sessionActiveTime.Nanoseconds() + timeutil.Since(startedAt).Nanoseconds())
+	}
+
 	return serverpb.Session{
 		Username:                   sd.SessionUser().Normalized(),
 		ClientAddress:              remoteStr,
 		ApplicationName:            ex.applicationName.Load().(string),
 		Start:                      ex.phaseTimes.GetSessionPhaseTime(sessionphase.SessionInit).UTC(),
 		ActiveQueries:              activeQueries,
 		ActiveTxn:                  activeTxnInfo,
+		NumTxnsExecuted:            int32(ex.extraTxnState.txnCounter),
+		TxnFingerprintIDs:          txnFingerprintIDs,
 		LastActiveQuery:            lastActiveQuery,
 		ID:                         ex.sessionID.GetBytes(),
 		AllocBytes:                 ex.mon.AllocBytes(),
 		MaxAllocBytes:              ex.mon.MaximumBytes(),
 		LastActiveQueryNoConstants: lastActiveQueryNoConstants,
 		Status:                     status,
+		TotalActiveTime:            sessionActiveTime,
 	}
 }
 

pkg/sql/conn_executor_exec.go

@@ -2110,6 +2110,14 @@ func (ex *connExecutor) onTxnFinish(ctx context.Context, ev txnEvent) {
 		ex.phaseTimes.SetSessionPhaseTime(sessionphase.SessionEndExecTransaction, timeutil.Now())
 		transactionFingerprintID :=
 			roachpb.TransactionFingerprintID(ex.extraTxnState.transactionStatementsHash.Sum())
+
+		err := ex.txnFingerprintIDCache.Add(transactionFingerprintID)
+		if err != nil {
+			if log.V(1) {
+				log.Warningf(ctx, "failed to enqueue transactionFingerprintID = %d: %s", transactionFingerprintID, err)
+			}
+		}
+
 		if !implicit {
 			ex.statsCollector.EndExplicitTransaction(
 				ctx,
@@ -2123,7 +2131,7 @@ func (ex *connExecutor) onTxnFinish(ctx context.Context, ev txnEvent) {
 				transactionFingerprintID,
 			)
 		}
-		err := ex.recordTransactionFinish(ctx, transactionFingerprintID, ev, implicit, txnStart)
+		err = ex.recordTransactionFinish(ctx, transactionFingerprintID, ev, implicit, txnStart)
 		if err != nil {
 			if log.V(1) {
 				log.Warningf(ctx, "failed to record transaction stats: %s", err)
@@ -2219,6 +2227,7 @@ func (ex *connExecutor) recordTransactionFinish(
 
 	txnEnd := timeutil.Now()
 	txnTime := txnEnd.Sub(txnStart)
+	ex.totalActiveTimeStopWatch.Stop()
 	if ex.executorType != executorTypeInternal {
 		ex.metrics.EngineMetrics.SQLTxnsOpen.Dec(1)
 	}

pkg/sql/conn_executor_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/kvserverbase"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
 	"github.com/cockroachdb/cockroach/pkg/security/username"
+	"github.com/cockroachdb/cockroach/pkg/server/serverpb"
 	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
 	"github.com/cockroachdb/cockroach/pkg/sql"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
@@ -1623,6 +1624,94 @@ func TestEmptyTxnIsBeingCorrectlyCounted(t *testing.T) {
 			"after executing empty transactions, but it was not")
 }
 
+//TestSessionTotalActiveTime tests that a session's total active time is
+//correctly being recorded as transactions are executed.
+func TestSessionTotalActiveTime(t *testing.T) {
+	defer leaktest.AfterTest(t)()
+	defer log.Scope(t).Close(t)
+
+	ctx := context.Background()
+	params := base.TestServerArgs{}
+	s, mainDB, _ := serverutils.StartServer(t, params)
+	defer s.Stopper().Stop(ctx)
+
+	_, err := mainDB.Exec(fmt.Sprintf("CREATE USER %s", username.TestUser))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	pgURL, cleanupDB := sqlutils.PGUrl(
+		t, s.ServingSQLAddr(), "TestSessionTotalActiveTime", url.User(username.TestUser))
+	defer cleanupDB()
+	rawSQL, err := gosql.Open("postgres", pgURL.String())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		err := rawSQL.Close()
+		if err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	getSessionWithTestUser := func() *serverpb.Session {
+		sessions := s.SQLServer().(*sql.Server).GetExecutorConfig().SessionRegistry.SerializeAll()
+		for _, s := range sessions {
+			if s.Username == username.TestUser {
+				return &s
+			}
+		}
+		t.Fatalf("expected session with username %s", username.TestUser)
+		return nil
+	}
+
+	sqlDB := sqlutils.MakeSQLRunner(rawSQL)
+	sqlDB.Exec(t, "SELECT 1")
+	session := getSessionWithTestUser()
+	activeTimeNanos := session.TotalActiveTime.Nanoseconds()
+
+	// We will execute different types of transactions.
+	// After each execution, verify the total active time has increased, but is no
+	// longer increasing after the transaction has completed.
+	testCases := []struct {
+		Query string
+		// SessionActiveAfterExecution signifies that the active time should still be active after this query.
+		SessionActiveAfterExecution bool
+	}{
+		{"SELECT 1", false},
+		// Test explicit transaction.
+		{"BEGIN", true},
+		{"SELECT 1", true},
+		{"SELECT  1, 2", true},
+		{"COMMIT", false},
+		{"BEGIN", true},
+		{"SELECT crdb_internal.force_retry('1s')", true},
+		{"COMMIT", false},
+	}
+
+	for _, tc := range testCases {
+		sqlDB.Exec(t, tc.Query)
+		if tc.Query == "crdb_internal.force_retry('1s'" {
+			continue
+		}
+		// Check that the total active time has increased.
+		session = getSessionWithTestUser()
+		require.Greater(t, session.TotalActiveTime.Nanoseconds(), activeTimeNanos)
+
+		activeTimeNanos = session.TotalActiveTime.Nanoseconds()
+		session = getSessionWithTestUser()
+
+		if tc.SessionActiveAfterExecution {
+			require.Greater(t, session.TotalActiveTime.Nanoseconds(), activeTimeNanos)
+		} else {
+			require.Equal(t, activeTimeNanos, session.TotalActiveTime.Nanoseconds())
+		}
+
+		activeTimeNanos = session.TotalActiveTime.Nanoseconds()
+	}
+}
+
 // dynamicRequestFilter exposes a filter method which is a
 // kvserverbase.ReplicaRequestFilter but can be set dynamically.
 type dynamicRequestFilter struct {

pkg/sql/crdb_internal.go

@@ -1910,6 +1910,7 @@ CREATE TABLE crdb_internal.%s (
   application_name   STRING,         -- the name of the application as per SET application_name
   active_queries     STRING,         -- the currently running queries as SQL
   last_active_query  STRING,         -- the query that finished last on this session as SQL
+  num_txns_executed  INT,            -- the number of transactions that were executed so far on this session
   session_start      TIMESTAMP,      -- the time when the session was opened
   oldest_query_start TIMESTAMP,      -- the time when the oldest query in the session was started
   kv_txn             STRING,         -- the ID of the current KV transaction
@@ -2011,6 +2012,7 @@ func populateSessionsTable(
 			tree.NewDString(session.ApplicationName),
 			tree.NewDString(activeQueries.String()),
 			tree.NewDString(session.LastActiveQuery),
+			tree.NewDInt(tree.DInt(session.NumTxnsExecuted)),
 			startTSDatum,
 			oldestStartDatum,
 			kvTxnIDDatum,
@@ -2036,6 +2038,7 @@ func populateSessionsTable(
 				tree.DNull,                             // application name
 				tree.NewDString("-- "+rpcErr.Message),  // active queries
 				tree.DNull,                             // last active query
+				tree.DNull,                             // num txns executed
 				tree.DNull,                             // session start
 				tree.DNull,                             // oldest_query_start
 				tree.DNull,                             // kv_txn

pkg/sql/delegate/show_sessions.go

@@ -16,7 +16,7 @@ import (
 )
 
 func (d *delegator) delegateShowSessions(n *tree.ShowSessions) (tree.Statement, error) {
-	const query = `SELECT node_id, session_id, status, user_name, client_address, application_name, active_queries, last_active_query, session_start, oldest_query_start FROM crdb_internal.`
+	const query = `SELECT node_id, session_id, status, user_name, client_address, application_name, active_queries, last_active_query, session_start, oldest_query_start, num_txns_executed FROM crdb_internal.`
 	table := `node_sessions`
 	if n.Cluster {
 		table = `cluster_sessions`