From c720e68f5378d27713c86baa6729e6b2b0ee1913 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= Date: Tue, 8 Aug 2017 19:54:12 +0300 Subject: [PATCH] MDEV-13472 rpl.rpl_semi_sync_wait_point crashes because of thd_destructor_proxy The thd_destructor_proxy detects that no transactions are active and starts srv_shutdown_bg_undo_sources(), but fails to take into account that new transactions can still start, especially be slave but also by other threads. In addition there is no mutex when checking for active transaction so this is not safe. We relax the failing InnoDB debug assertion by allowing the execution of user transactions after the purge thread has been shut down. FIXME: If innodb_fast_shutdown=0, we should somehow guarantee that no new transactions can start after thd_destructor_proxy observed that trx_sys_any_active_transactions() did not hold. --- storage/innobase/trx/trx0purge.cc | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/storage/innobase/trx/trx0purge.cc b/storage/innobase/trx/trx0purge.cc index 317087173c5..e22bbd61162 100644 --- a/storage/innobase/trx/trx0purge.cc +++ b/storage/innobase/trx/trx0purge.cc @@ -293,14 +293,16 @@ trx_purge_add_update_undo_to_history( After the purge thread has been given permission to exit, in fast shutdown, we may roll back transactions (trx->undo_no==0) - in THD::cleanup() invoked from unlink_thd(). */ + in THD::cleanup() invoked from unlink_thd(), and we may also + continue to execute user transactions. */ ut_ad(srv_undo_sources || ((srv_startup_is_before_trx_rollback_phase || trx_rollback_or_clean_is_active) && purge_sys->state == PURGE_STATE_INIT) || (srv_force_recovery >= SRV_FORCE_NO_BACKGROUND && purge_sys->state == PURGE_STATE_DISABLED) - || (trx->undo_no == 0 && srv_fast_shutdown)); + || ((trx->undo_no == 0 || trx->in_mysql_trx_list) + && srv_fast_shutdown)); /* Add the log as the first in the history list */ flst_add_first(rseg_header + TRX_RSEG_HISTORY,