Commit b0e1389b authored by unknown's avatar unknown
Browse files

This code change has 0 effects as it's about the case where innobase_very_fast_shutdown!=0, 

which is always false. In a very fast InnoDB shutdown, we just ensure that
no more transactions are running, flush InnoDB log, signal InnoDB threads to die,
and then return from InnoDB (from innobase_end()) without waiting for those threads
to actually die. I have tested on a 4CPU machine that even with --innodb_flush_log_at_trx_commit=0,
this optimized InnoDB very fast shutdown loses no committed transactions. Patch pre-approved by Heikki.


innobase/log/log0log.c:
  In an InnoDB very fast shutdown, we just need to wait for no more transactions to be happening
  and then we can flush the InnoDB log and don't need to wait for the
  signaled-to-die InnoDB threads to finish (saves seconds).
innobase/srv/srv0start.c:
  In an InnoDB very fast shutdown, once we have forced a flush of the InnoDB
  log to disk, and signalled InnoDB threads to die, we needn't wait
  for these threads to die.
parent 50985b67

innobase/log/log0log.c

+25 −24
Original line number Diff line number Diff line
@@ -3047,7 +3047,10 @@ logs_empty_and_mark_files_at_shutdown(void) 


	mutex_enter(&kernel_mutex);



	/* Check that there are no longer transactions */

       /* Check that there are no longer transactions. We need this wait even

        for the 'very fast' shutdown, because the InnoDB layer may have

        committed or prepared transactions and we don't want to lose them. */



	if (trx_n_mysql_transactions > 0

			|| UT_LIST_GET_LEN(trx_sys->trx_list) > 0) {
@@ -3056,6 +3059,23 @@ logs_empty_and_mark_files_at_shutdown(void) 
		goto loop;

	}



        if (srv_very_fast_shutdown) {

               /* In a 'very fast' shutdown we do not flush the buffer pool:

               it is essentially a 'crash' of the InnoDB server.

                Make sure that the log is all flushed to disk, so that

               we can recover all committed transactions in a crash

               recovery.

               In a 'very fast' shutdown we do not flush the buffer pool:

               it is essentially a 'crash' of the InnoDB server. Then we must

               not write the lsn stamps to the data files, since at a

               startup InnoDB deduces from the stamps if the previous

               shutdown was clean. */



               log_buffer_flush_to_disk();

                return; /* We SKIP ALL THE REST !! */

       }





	/* Check that the master thread is suspended */



	if (srv_n_threads_active[SRV_MASTER] != 0) {
@@ -3092,24 +3112,13 @@ logs_empty_and_mark_files_at_shutdown(void) 
	log_archive_all();

#endif /* UNIV_LOG_ARCHIVE */



	if (!srv_very_fast_shutdown) {

		/* In a 'very fast' shutdown we do not flush the buffer pool:

		it is essentially a 'crash' of the InnoDB server. */



		log_make_checkpoint_at(ut_dulint_max, TRUE);

	} else {

		/* Make sure that the log is all flushed to disk, so that

		we can recover all committed transactions in a crash

		recovery */

		log_buffer_flush_to_disk();

	}



	mutex_enter(&(log_sys->mutex));



	lsn = log_sys->lsn;



	if ((ut_dulint_cmp(lsn, log_sys->last_checkpoint_lsn) != 0

	    && !srv_very_fast_shutdown)

       if ((ut_dulint_cmp(lsn, log_sys->last_checkpoint_lsn) != 0)

#ifdef UNIV_LOG_ARCHIVE

	   || (srv_log_archive_on

	       && ut_dulint_cmp(lsn,
@@ -3158,7 +3167,7 @@ logs_empty_and_mark_files_at_shutdown(void) 
	completely flushed to disk! (We do not call fil_write... if the

	'very fast' shutdown is enabled.) */



	if (!srv_very_fast_shutdown && !buf_all_freed()) {

       if (!buf_all_freed()) {



		goto loop;

	}
@@ -3181,7 +3190,7 @@ logs_empty_and_mark_files_at_shutdown(void) 


	/* Make some checks that the server really is quiet */

	ut_a(srv_n_threads_active[SRV_MASTER] == 0);

	ut_a(srv_very_fast_shutdown || buf_all_freed());

       ut_a(buf_all_freed());

	ut_a(0 == ut_dulint_cmp(lsn, log_sys->lsn));



	if (ut_dulint_cmp(lsn, srv_start_lsn) < 0) {
@@ -3196,15 +3205,7 @@ logs_empty_and_mark_files_at_shutdown(void) 


	srv_shutdown_lsn = lsn;



	if (!srv_very_fast_shutdown) {

		/* In a 'very fast' shutdown we do not flush the buffer pool:

		it is essentially a 'crash' of the InnoDB server. Then we must

		not write the lsn stamps to the data files, since at a

		startup InnoDB deduces from the stamps if the previous

		shutdown was clean. */



		fil_write_flushed_lsn_to_data_files(lsn, arch_log_no);

	}



	fil_flush_file_spaces(FIL_TABLESPACE);
@@ -3212,7 +3213,7 @@ logs_empty_and_mark_files_at_shutdown(void) 


	/* Make some checks that the server really is quiet */

	ut_a(srv_n_threads_active[SRV_MASTER] == 0);

	ut_a(srv_very_fast_shutdown || buf_all_freed());

       ut_a(buf_all_freed());

	ut_a(0 == ut_dulint_cmp(lsn, log_sys->lsn));

}

innobase/srv/srv0start.c

+7 −0
Original line number Diff line number Diff line
@@ -1740,6 +1740,13 @@ innobase_shutdown_for_mysql(void) 


	srv_shutdown_state = SRV_SHUTDOWN_EXIT_THREADS;



        /* In a 'very fast' shutdown, we do not need to wait for these threads

        to die; all which counts is that we flushed the log; a 'very fast'

        shutdown is essentially a crash. */



        if (srv_fast_shutdown)

          return((int) DB_SUCCESS);



	/* All threads end up waiting for certain events. Put those events

	to the signaled state. Then the threads will exit themselves in

	os_thread_event_wait(). */