InnoDB: Truncate SHOW INNODB STATUS output at the start of the list

of active transactions, if necessary and possible.  (Bug #5436)


innobase/include/lock0lock.h:
  Split lock_print_info() into lock_print_info_summary()
  and lock_print_info_all_transactions().
innobase/lock/lock0lock.c:
  Split lock_print_info() into lock_print_info_summary()
  and lock_print_info_all_transactions().
innobase/include/srv0srv.h:
  srv_printf_innodb_monitor(): Add output parameters trx_start and trx_end.
innobase/srv/srv0srv.c:
  srv_printf_innodb_monitor(): Add output parameters trx_start and trx_end.
sql/ha_innodb.cc:
  innodb_show_status(): Truncate oversized output at the beginning
  of the list of active transactions, if possible.

4 files changed, 61 insertions, 20 deletions

diff --git a/innobase/include/lock0lock.h b/innobase/include/lock0lock.h
index 1fd7492d517..74288d57285 100644
--- a/innobase/include/lock0lock.h
+++ b/innobase/include/lock0lock.h
@@ -530,8 +530,15 @@ lock_rec_print(
 Prints info of locks for all transactions. */
 
 void
-lock_print_info(
-/*============*/
+lock_print_info_summary(
+/*====================*/
+	FILE*	file);	/* in: file where to print */
+/*************************************************************************
+Prints info of locks for each transaction. */
+
+void
+lock_print_info_all_transactions(
+/*=============================*/
 	FILE*	file);	/* in: file where to print */
 /*************************************************************************
 Validates the lock queue on a table. */
diff --git a/innobase/include/srv0srv.h b/innobase/include/srv0srv.h
index 4e9e25844aa..4352083b21f 100644
--- a/innobase/include/srv0srv.h
+++ b/innobase/include/srv0srv.h
@@ -398,7 +398,11 @@ Outputs to a file the output of the InnoDB Monitor. */
 void
 srv_printf_innodb_monitor(
 /*======================*/
-	FILE*	file);	/* in: output stream */
+	FILE*	file,		/* in: output stream */
+	ulint*	trx_start,	/* out: file position of the start of
+				the list of active transactions */
+	ulint*	trx_end);	/* out: file position of the end of
+				the list of active transactions */
 
 
 /* Types for the threads existing in the system. Threads of types 4 - 9
diff --git a/innobase/lock/lock0lock.c b/innobase/lock/lock0lock.c
index 29a274261f8..1c08d3defaa 100644
--- a/innobase/lock/lock0lock.c
+++ b/innobase/lock/lock0lock.c
@@ -4126,21 +4126,10 @@ lock_get_n_rec_locks(void)
 Prints info of locks for all transactions. */
 
 void
-lock_print_info(
-/*============*/
+lock_print_info_summary(
+/*====================*/
 	FILE*	file)	/* in: file where to print */
 {
-	lock_t*	lock;
-	trx_t*	trx;
-	ulint	space;
-	ulint	page_no;
-	page_t*	page;
-	ibool	load_page_first = TRUE;
-	ulint	nth_trx		= 0;
-	ulint	nth_lock	= 0;
-	ulint	i;
-	mtr_t	mtr;
-
 	/* We must protect the MySQL thd->query field with a MySQL mutex, and
 	because the MySQL mutex must be reserved before the kernel_mutex of
 	InnoDB, we call innobase_mysql_prepare_print_arbitrary_thd() here. */
@@ -4179,6 +4168,26 @@ lock_print_info(
 	fprintf(file,
 		"Total number of lock structs in row lock hash table %lu\n",
 					 (ulong) lock_get_n_rec_locks());
+}
+
+/*************************************************************************
+Prints info of locks for each transaction. */
+
+void
+lock_print_info_all_transactions(
+/*=============================*/
+	FILE*	file)	/* in: file where to print */
+{
+	lock_t*	lock;
+	ulint	space;
+	ulint	page_no;
+	page_t*	page;
+	ibool	load_page_first = TRUE;
+	ulint	nth_trx		= 0;
+	ulint	nth_lock	= 0;
+	ulint	i;
+	mtr_t	mtr;
+	trx_t*	trx;
 
 	fprintf(file, "LIST OF TRANSACTIONS FOR EACH SESSION:\n");
 
diff --git a/innobase/srv/srv0srv.c b/innobase/srv/srv0srv.c
index a60e9e5a5f7..e56389a8541 100644
--- a/innobase/srv/srv0srv.c
+++ b/innobase/srv/srv0srv.c
@@ -1470,7 +1470,11 @@ Outputs to a file the output of the InnoDB Monitor. */
 void
 srv_printf_innodb_monitor(
 /*======================*/
-	FILE*	file)	/* in: output stream */
+	FILE*	file,		/* in: output stream */
+	ulint*	trx_start,	/* out: file position of the start of
+				the list of active transactions */
+	ulint*	trx_end)	/* out: file position of the end of
+				the list of active transactions */
 {
 	double	time_elapsed;
 	time_t	current_time;
@@ -1519,7 +1523,24 @@ srv_printf_innodb_monitor(
 
 	mutex_exit(&dict_foreign_err_mutex);
 
-	lock_print_info(file);
+	lock_print_info_summary(file);
+	if (trx_start) {
+		long	t = ftell(file);
+		if (t < 0) {
+			*trx_start = ULINT_UNDEFINED;
+		} else {
+			*trx_start = (ulint) t;
+		}
+	}
+	lock_print_info_all_transactions(file);
+	if (trx_end) {
+		long	t = ftell(file);
+		if (t < 0) {
+			*trx_end = ULINT_UNDEFINED;
+		} else {
+			*trx_end = (ulint) t;
+		}
+	}
 	fputs("--------\n"
 		"FILE I/O\n"
 		"--------\n", file);
@@ -1672,13 +1693,13 @@ loop:
 	    last_monitor_time = time(NULL);
 
 	    if (srv_print_innodb_monitor) {
-		srv_printf_innodb_monitor(stderr);
+		srv_printf_innodb_monitor(stderr, NULL, NULL);
 	    }
 
 	    if (srv_innodb_status) {
 		mutex_enter(&srv_monitor_file_mutex);
 		rewind(srv_monitor_file);
-		srv_printf_innodb_monitor(srv_monitor_file);
+		srv_printf_innodb_monitor(srv_monitor_file, NULL, NULL);
 		os_file_set_eof(srv_monitor_file);
 		mutex_exit(&srv_monitor_file_mutex);
 	    }