maria-developers team mailing list archive

[김경남 <knamkim@xxxxxxxxx>]

Hi,Sergei !
Thanks for the reply and your help.

I'll tell you my problem in detail.
As I mentioned my last letter, I'm develping mariadb monitoring tool as
a daemon plugin type.
Source version is 10.1.3-MariaDB-wsrep-debug-log.

 

When I run install plugin command, server crashed.
So for test, I removed comment line by line. 
Here is source.
--------- source
------------------------------------------------------------
pthread_handler_t monm_monitor(void *p)
{
 DBUG_ENTER("monm_plugin_test");
 ...
 
 THD* thd;
 thd = new THD;  --> at this point, error occurred.
 //thd->thread_stack= (char*) &thd;
  //thd->store_globals();
 //tables.init_one_table("performance_schema", 18,
"events_statements_current", 25, "events_statements_current", TL_READ);
 //open_and_lock_tables(thd, &tables, FALSE, MYSQL_LOCK_IGNORE_TIMEOUT);
 while(1)
 {
  ...
 }
}
------------------------------------------------------------------------
---------
At that time,  error messag is below,
------------------------------------------------------------------------
---------
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x0):
Connection ID (thread ID): 0
Status: NOT_KILLED

Here is gdb bt result.
------------------------------------------------------------------------
---------
#0  0x000000385cc0c8ac in pthread_kill () from /lib64/libpthread.so.0
#1  0x0000000000c4a270 in my_write_core (sig=11) at
/home/windfree/workspace/ws-mariadb/maria-mon/mysys/stacktrace.c:457
#2  0x0000000000754053 in handle_fatal_signal (sig=11) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/signal_handler.cc:266
#3  <signal handler called>
#4  my_thread_name () at
/home/windfree/workspace/ws-mariadb/maria-mon/mysys/my_thr_init.c:416
#5  0x0000000000c56574 in wt_thd_lazy_init (thd=0x7fc3a8003a90,
ds=0x7fc3a80012e8, ts=0x7fc3a80012e0, dl=0x7fc3a80012f8,
tl=0x7fc3a80012f0)
    at
/home/windfree/workspace/ws-mariadb/maria-mon/mysys/waiting_threads.c:51
1
#6  0x0000000000598752 in THD::THD (this=0x7fc3a8000930,
is_wsrep_applier=false) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_class.cc:1015
#7  0x00007fc3f7851205 in monm_monitor (p=<value optimized out>) at
/home/windfree/workspace/ws-mariadb/maria-mon/plugin/monm/monm_plugin_in
fo.cc:70
#8  0x000000385cc079d1 in start_thread () from /lib64/libpthread.so.0
#9  0x000000385c4e88fd in clone () from /lib64/libc.so.6
------------------------------------------------------------------------
------------------------------------


In addition, I moved that source line to init function as below.
And for test, I removed comment line by line.
At this time, An error occurred at another line. 

When I removed comment of source line (thd->store_globals()) and run
install plugin command, server crashed .


----- source
----------------------------------------------------------------------
static int monm_plugin_init(void *p __attribute__ ((unused)))
{
  ...
 thd = new THD;  
 thd->thread_stack= (char*) &thd;
 thd->store_globals(); // --> at this point, error occurred
 //tables.init_one_table("performance_schema", 18,
"events_statements_current", 25, "events_statements_current", TL_READ);
 //open_and_lock_tables(thd, &tables, FALSE, MYSQL_LOCK_IGNORE_TIMEOUT);
 ...
 ...
}

------------------------------------------------------------------------
---------

At that time,  error messag is below,
------------------------------------------------------------------------
---------
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x0):
Connection ID (thread ID): 0
Status: NOT_KILLED

Here is gdb bt result.
------------------------------------------------------------------------
---------
#0  0x000000385cc0c8ac in pthread_kill () from /lib64/libpthread.so.0
#1  0x0000000000c4a270 in my_write_core (sig=6) at
/home/windfree/workspace/ws-mariadb/maria-mon/mysys/stacktrace.c:457
#2  0x0000000000754053 in handle_fatal_signal (sig=6) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/signal_handler.cc:266
#3  <signal handler called>
#4  0x000000385c432625 in raise () from /lib64/libc.so.6
#5  0x000000385c433e05 in abort () from /lib64/libc.so.6
#6  0x000000385c42b74e in __assert_fail_base () from /lib64/libc.so.6
#7  0x000000385c42b810 in __assert_fail () from /lib64/libc.so.6
#8  0x00000000007584a2 in handler::ha_thd (this=0x7f91e4023f18) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/handler.cc:2453
#9  0x000000000075eaf7 in mark_trx_read_write (this=0x7f91e4023f18,
buf=0x7f91e4014cf8 "\004monm")
    at /home/windfree/workspace/ws-mariadb/maria-mon/sql/handler.cc:3929
#10 handler::ha_write_row (this=0x7f91e4023f18, buf=0x7f91e4014cf8
"\004monm") at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/handler.cc:5852
#11 0x00000000005d53b0 in finalize_install (thd=0x47ecad0,
table=0x7f91e40140d0, name=0x47f12f0, argc=0x7f923c3dcc3c, argv=<value
optimized out>)
    at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_plugin.cc:2077
#12 0x00000000005d76ba in mysql_install_plugin (thd=0x47ecad0,
name=0x47f12f0, dl_arg=<value optimized out>)
    at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_plugin.cc:2151
#13 0x00000000005cb430 in mysql_execute_command (thd=0x47ecad0) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_parse.cc:5445
#14 0x00000000005cb614 in mysql_parse (thd=0x47ecad0,
rawbuf=0x7f91e40033c8 "install plugin monm soname 'libmonm.so'",
length=<value optimized out>,
    parser_state=0x7f923c3de740) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_parse.cc:7141
#15 0x00000000005ccb1a in dispatch_command (command=COM_QUERY,
thd=0x47ecad0, packet=<value optimized out>, packet_length=39)
    at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_parse.cc:1462
#16 0x00000000005ceaeb in do_command (thd=0x47ecad0) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_parse.cc:1092
#17 0x000000000069c8d7 in do_handle_one_connection (thd_arg=<value
optimized out>) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_connect.cc:1347
#18 0x000000000069cab3 in handle_one_connection (arg=0x47ecad0) at
/home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_connect.cc:1258
#19 0x0000000000c0b44a in pfs_spawn_thread (arg=0x47f6900) at
/home/windfree/workspace/ws-mariadb/maria-mon/storage/perfschema/pfs.cc:
1860
#20 0x000000385cc079d1 in start_thread () from /lib64/libpthread.so.0
#21 0x000000385c4e88fd in clone () from /lib64/libc.so.6

------------------------------------------------------------------------
----------------

 

I don't know the reason of this error.

 

Regards,

Kyungnam.


 

----------------------------Original Message----------------------------
From: Sergei Golubchik(serg@xxxxxxxxxxx)
To: 김경남/부책임연구원/신기술개발팀
Cc: community list[maria-developers@xxxxxxxxxxxxxxxxxxx]
Date: 2015.03.27 01:33 
Subject: Re: In daemon plugin, THD problem. 



Hi, 김경남!

On Mar 26, 김경남 wrote:
> Hi, Sergei!
>
> I'm writing daemon plugin . I hava a problem and don't find soultion
> yet.
>
> In monm_monitor function,
>
> THD* thd    cause server crash. so  I examined coredump.
>
> #6  0x0000000000598752 in THD::THD (this=0x7f9b64000930,
is_wsrep_applier=false) at
> /home/windfree/workspace/ws-mariadb/maria-mon/sql/sql_class.cc:1015
>
> I don't know the reason of crash.

Neither do I. What MariaDB version do you use? 10.1.2? 10.1.3?
I don't see how it could've crashed on that line.

Please, show the complete stack trace ('bt' command) and lines around
sql_class.cc:1015.

Regards,
Sergei


 


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