2020-04-23  8:54:58 0 [Note] /ten1/builds/10.5-2655984e-deb/bin/mysqld (initiated by: root[root] @ localhost [127.0.0.1]): Normal shutdown

2020-04-23  8:54:58 0 [Note] Event Scheduler: Purging the queue. 0 events

Got error 22 when trying to lock mutex LOCK_rpl_thread_pool at /home/elenst/src/10.5/sql/rpl_parallel.cc, line 500

200423  8:54:58 [ERROR] mysqld got signal 6 ;

#3  <signal handler called>

#4  0x00007f43283f2207 in raise () from /lib64/libc.so.6

#5  0x00007f43283f38f8 in abort () from /lib64/libc.so.6

#6  0x000056135e2a6474 in safe_mutex_lock (mp=0x56135f273d90 <global_rpl_thread_pool+16>, my_flags=0, file=0x56135e4c6060 "/home/elenst/src/10.5/sql/rpl_parallel.cc", line=500) at /home/elenst/src/10.5/mysys/thr_mutex.c:297

#7  0x000056135d82b3e3 in inline_mysql_mutex_lock (that=0x56135f273d90 <global_rpl_thread_pool+16>, src_file=0x56135e4c6060 "/home/elenst/src/10.5/sql/rpl_parallel.cc", src_line=500) at /home/elenst/src/10.5/include/mysql/psi/mysql_thread.h:763

#8  0x000056135d82d016 in pool_mark_not_busy (pool=0x56135f273d80 <global_rpl_thread_pool>) at /home/elenst/src/10.5/sql/rpl_parallel.cc:500

#9  0x000056135d82d280 in rpl_unpause_after_ftwrl (thd=0x7f42b0000b18) at /home/elenst/src/10.5/sql/rpl_parallel.cc:537

#10 0x000056135d605bb0 in mysql_execute_command (thd=0x7f42b0000b18) at /home/elenst/src/10.5/sql/sql_parse.cc:5433

#11 0x000056135d60dcda in mysql_parse (thd=0x7f42b0000b18, rawbuf=0x7f42b0012580 "FLUSH /* QNO 3372 CON_ID 10 */ TABLES WITH READ LOCK", length=52, parser_state=0x7f43107bd520, is_com_multi=false, is_next_command=false) at /home/elenst/src/10.5/sql/sql_parse.cc:7957

#12 0x000056135d5f962c in dispatch_command (command=COM_QUERY, thd=0x7f42b0000b18, packet=0x7f42b0008929 "FLUSH /* QNO 3372 CON_ID 10 */ TABLES WITH READ LOCK", packet_length=52, is_com_multi=false, is_next_command=false) at /home/elenst/src/10.5/sql/sql_parse.cc:1840

#13 0x000056135d5f7ca8 in do_command (thd=0x7f42b0000b18) at /home/elenst/src/10.5/sql/sql_parse.cc:1359

#14 0x000056135d79e479 in do_handle_one_connection (connect=0x56136289ed68, put_in_cache=true) at /home/elenst/src/10.5/sql/sql_connect.cc:1422

#15 0x000056135d79e192 in handle_one_connection (arg=0x56136289ed68) at /home/elenst/src/10.5/sql/sql_connect.cc:1319

#16 0x000056135dcdc84c in pfs_spawn_thread (arg=0x561362781be8) at /home/elenst/src/10.5/storage/perfschema/pfs.cc:2201

#17 0x00007f4329a28dd5 in start_thread () from /lib64/libpthread.so.0

#18 0x00007f43284b9ead in clone () from /lib64/libc.so.6

(gdb) bt

#0  pool_mark_busy (pool=0x5555576f07e0 <global_rpl_thread_pool>, thd=0x0) at /home/sachin/10.4/server/sql/rpl_parallel.cc:455

#1  0x0000555555f67532 in rpl_parallel_change_thread_count (pool=0x5555576f07e0 <global_rpl_thread_pool>, new_count=0, force=true) at /home/sachin/10.4/server/sql/rpl_parallel.cc:1530

#2  0x0000555555f68e88 in rpl_parallel_thread_pool::destroy (this=0x5555576f07e0 <global_rpl_thread_pool>) at /home/sachin/10.4/server/sql/rpl_parallel.cc:2017

#3  0x0000555555c51eb3 in slave_prepare_for_shutdown () at /home/sachin/10.4/server/sql/slave.cc:1448

#4  0x0000555555c1eb89 in close_connections () at /home/sachin/10.4/server/sql/mysqld.cc:1765

#5  0x0000555555c2785b in mysqld_main (argc=131, argv=0x555557f868e0) at /home/sachin/10.4/server/sql/mysqld.cc:5936

#6  0x0000555555c1b77a in main (argc=7, argv=0x7fffffffb2c8) at /home/sachin/10.4/server/sql/main.cc:25

(gdb)

--source include/master-slave.inc

--connection master

--connection slave

stop slave;

SET GLOBAL slave_parallel_threads=10;

set global slave_parallel_mode=optimistic;

change master to master_use_gtid=slave_pos;

start slave;

--connect (con1,127.0.0.1,root,,test,$SLAVE_MYPORT)

SET DEBUG_DBUG='+d,sleep_mark_busy';

--send

  FLUSH TABLES WITH READ LOCK;

--connection slave

--source include/rpl_restart_server.inc

--connection slave

stop slave;

SET GLOBAL slave_parallel_threads=0;

set global slave_parallel_mode=conservative;

start slave;

--disconnect con1

--source include/rpl_end.inc

diff --git a/sql/rpl_parallel.cc b/sql/rpl_parallel.cc

index 9344312fe62..1dea1caae7e 100644

--- a/sql/rpl_parallel.cc

+++ b/sql/rpl_parallel.cc

@@ -467,6 +467,7 @@ pool_mark_busy(rpl_parallel_thread_pool *pool, THD *thd)

     So we protect the infrequent operations of FLUSH TABLES WITH READ LOCK and

     pool size changes with this condition wait.

   */

+  DBUG_EXECUTE_IF("sleep_mark_busy",my_sleep(1000000););

   mysql_mutex_lock(&pool->LOCK_rpl_thread_pool);

   if (thd)

   {

@@ -511,6 +512,8 @@ rpl_unpause_after_ftwrl(THD *thd)

   uint32 i;

   rpl_parallel_thread_pool *pool= &global_rpl_thread_pool;

   DBUG_ENTER("rpl_unpause_after_ftwrl");

+  if (!pool->count)

+    DBUG_VOID_RETURN;

   DBUG_ASSERT(pool->busy);

@@ -552,6 +555,8 @@ rpl_pause_for_ftwrl(THD *thd)

   int err;

   DBUG_ENTER("rpl_pause_for_ftwrl");

+  if (!pool->count)

+    DBUG_RETURN(0);

   /*

     While the count_pending_pause_for_ftwrl counter is non-zero, the pool

     cannot be shutdown/resized, so threads are guaranteed to not disappear.