Avoid InnoDB messages about recovery after creating redo logs

srv_log_files_created: A debug flag to ensure that InnoDB redo log
files can only be created once in the server lifetime, and that
after log files have been created, no crash recovery will take place.

recv_scan_log_recs(): Detect the special case where the log consists
of a sole MLOG_CHECKPOINT record, such as immediately after creating
the redo logs.

recv_recovery_from_checkpoint_start(): Skip the recovery message
if the redo log is logically empty.

3 files changed, 30 insertions, 1 deletions

diff --git a/storage/innobase/include/srv0srv.h b/storage/innobase/include/srv0srv.h
index 6afa1bf7e4e..4704625e1fe 100644
--- a/storage/innobase/include/srv0srv.h
+++ b/storage/innobase/include/srv0srv.h
@@ -546,7 +546,10 @@ extern my_bool	srv_purge_view_update_only_debug;
 
 /** Value of MySQL global used to disable master thread. */
 extern my_bool	srv_master_thread_disabled_debug;
+/** InnoDB system tablespace to set during recovery */
 extern uint	srv_sys_space_size_debug;
+/** whether redo log files have been created at startup */
+extern bool	srv_log_files_created;
 #endif /* UNIV_DEBUG */
 
 #define SRV_SEMAPHORE_WAIT_EXTENSION	7200
diff --git a/storage/innobase/log/log0recv.cc b/storage/innobase/log/log0recv.cc
index e48e185274a..71ce7c82a65 100644
--- a/storage/innobase/log/log0recv.cc
+++ b/storage/innobase/log/log0recv.cc
@@ -2806,7 +2806,24 @@ recv_scan_log_recs(
 
 		scanned_lsn += data_len;
 
+		if (data_len == LOG_BLOCK_HDR_SIZE + SIZE_OF_MLOG_CHECKPOINT
+		    && scanned_lsn == checkpoint_lsn + SIZE_OF_MLOG_CHECKPOINT
+		    && log_block[LOG_BLOCK_HDR_SIZE] == MLOG_CHECKPOINT
+		    && checkpoint_lsn == mach_read_from_8(LOG_BLOCK_HDR_SIZE
+							  + 1 + log_block)) {
+			/* The redo log is logically empty. */
+			ut_ad(recv_sys->mlog_checkpoint_lsn == 0
+			      || recv_sys->mlog_checkpoint_lsn
+			      == checkpoint_lsn);
+			recv_sys->mlog_checkpoint_lsn = checkpoint_lsn;
+			DBUG_PRINT("ib_log", ("found empty log; LSN=" LSN_PF,
+					      scanned_lsn));
+			finished = true;
+			break;
+		}
+
 		if (scanned_lsn > recv_sys->scanned_lsn) {
+			ut_ad(!srv_log_files_created);
 			if (!recv_needed_recovery) {
 				recv_needed_recovery = true;
 
@@ -3244,7 +3261,11 @@ recv_recovery_from_checkpoint_start(lsn_t flush_lsn)
 	there is something wrong we will print a message to the
 	user about recovery: */
 
-	if (checkpoint_lsn != flush_lsn) {
+	if (flush_lsn == checkpoint_lsn + SIZE_OF_MLOG_CHECKPOINT
+	    && recv_sys->mlog_checkpoint_lsn == checkpoint_lsn) {
+		/* The redo log is logically empty. */
+	} else if (checkpoint_lsn != flush_lsn) {
+		ut_ad(!srv_log_files_created);
 
 		if (checkpoint_lsn + SIZE_OF_MLOG_CHECKPOINT < flush_lsn) {
 			ib::warn() << " Are you sure you are using the"
diff --git a/storage/innobase/srv/srv0start.cc b/storage/innobase/srv/srv0start.cc
index ee475d43e87..e625ab84334 100644
--- a/storage/innobase/srv/srv0start.cc
+++ b/storage/innobase/srv/srv0start.cc
@@ -147,6 +147,8 @@ UNIV_INTERN bool	srv_undo_sources;
 #ifdef UNIV_DEBUG
 /** InnoDB system tablespace to set during recovery */
 UNIV_INTERN uint	srv_sys_space_size_debug;
+/** whether redo log files have been created at startup */
+UNIV_INTERN bool	srv_log_files_created;
 #endif /* UNIV_DEBUG */
 
 /** Bit flags for tracking background thread creation. They are used to
@@ -526,6 +528,9 @@ create_log_files_rename(
 	we need to explicitly flush the log buffers. */
 	fil_flush(SRV_LOG_SPACE_FIRST_ID);
 
+	ut_ad(!srv_log_files_created);
+	ut_d(srv_log_files_created = true);
+
 	DBUG_EXECUTE_IF("innodb_log_abort_9", return(DB_ERROR););
 	DBUG_PRINT("ib_log", ("After innodb_log_abort_9"));