Description:
When executing a concurrent workload with BACKUP/RESTORE and DDL, mysqld ended up with a 100% CPU loop with the following stack trace:
#0 0x000000315b00df5b in read () from /lib64/libpthread.so.0
#1 0x0000000000a014cd in my_read (Filedes=87, Buffer=0x3053e29 "ЧЧ\a\001", Count=1048575, MyFlags=16) at my_read.c:50
#2 0x00000000009d3123 in myisam_backup::File_backup::get_data (this=0x2e977b8, buf=@0x2de3160) at myisam_backup_engine.cc:1227
#3 0x00000000009d322a in myisam_backup::Log_backup::get_data (this=0x2e977a0, buf=@0x2de3160) at myisam_backup_engine.cc:1175
#4 0x00000000009d5a4f in myisam_backup::Backup::get_data (this=0x2e971a0, buf=@0x2de3160) at myisam_backup_engine.cc:712
#5 0x0000000000adf647 in backup::Backup_pump::pump (this=0x2de3120, howmuch=0x7fd18f2fbfb8) at data_backup.cc:1405
#6 0x0000000000ae03a1 in backup::Scheduler::step (this=0x7fd18f2fc030) at data_backup.cc:836
#7 0x0000000000ae11d7 in backup::write_table_data (thd=0x7fd1881f2cb8, info=@0x2fc9820, s=@0x2e4bdd0) at data_backup.cc:666
#8 0x0000000000ad6fbb in Backup_restore_ctx::do_backup (this=0x7fd18f2fc220) at kernel.cc:1395
#9 0x0000000000ad9bcc in execute_backup_command (thd=0x7fd1881f2cb8, lex=0x7fd1881f4588, backupdir=0x7fd18f2fd1a0, overwrite=false, skip_gap_event=false)
at kernel.cc:269
#10 0x000000000068549f in mysql_execute_command (thd=0x7fd1881f2cb8) at sql_parse.cc:2482
#11 0x000000000068d0cf in mysql_parse (thd=0x7fd1881f2cb8,
inBuf=0x2deb850 "BACKUP DATABASE testdb_N TO '/tmp/gentest8496-1259752997.14649-0.295562722390549.tmp'", length=85, found_semicolon=0x7fd18f2fdf00)
at sql_parse.cc:5985
#12 0x000000000068dd38 in dispatch_command (command=COM_QUERY, thd=0x7fd1881f2cb8,
packet=0x7fd1881fd829 "BACKUP DATABASE testdb_N TO '/tmp/gentest8496-1259752997.14649-0.295562722390549.tmp' ", packet_length=86) at sql_parse.cc:1078
#13 0x000000000068f2aa in do_command (thd=0x7fd1881f2cb8) at sql_parse.cc:760
#14 0x000000000067bff8 in handle_one_connection (arg=0x7fd1881f2cb8) at sql_connect.cc:1164
#15 0x000000315b0073da in start_thread () from /lib64/libpthread.so.0
#16 0x000000315a4e627d in clone () from /lib64/libc.so.6
strace reports an infinite progression of read calls
[pid 8497] read(87, ""..., 1048575) = 0
meaning that EOF is being returned by read() but does not cause BACKUP to give up. The file descriptor 87 is connected to var/tmp/#sql210a_8_0-backuplog, which has a file size of zero.
How to repeat:
If this is repeatable, a test case will be provided.
In the meantime, the core and the binary will be made available.
Description: When executing a concurrent workload with BACKUP/RESTORE and DDL, mysqld ended up with a 100% CPU loop with the following stack trace: #0 0x000000315b00df5b in read () from /lib64/libpthread.so.0 #1 0x0000000000a014cd in my_read (Filedes=87, Buffer=0x3053e29 "ЧЧ\a\001", Count=1048575, MyFlags=16) at my_read.c:50 #2 0x00000000009d3123 in myisam_backup::File_backup::get_data (this=0x2e977b8, buf=@0x2de3160) at myisam_backup_engine.cc:1227 #3 0x00000000009d322a in myisam_backup::Log_backup::get_data (this=0x2e977a0, buf=@0x2de3160) at myisam_backup_engine.cc:1175 #4 0x00000000009d5a4f in myisam_backup::Backup::get_data (this=0x2e971a0, buf=@0x2de3160) at myisam_backup_engine.cc:712 #5 0x0000000000adf647 in backup::Backup_pump::pump (this=0x2de3120, howmuch=0x7fd18f2fbfb8) at data_backup.cc:1405 #6 0x0000000000ae03a1 in backup::Scheduler::step (this=0x7fd18f2fc030) at data_backup.cc:836 #7 0x0000000000ae11d7 in backup::write_table_data (thd=0x7fd1881f2cb8, info=@0x2fc9820, s=@0x2e4bdd0) at data_backup.cc:666 #8 0x0000000000ad6fbb in Backup_restore_ctx::do_backup (this=0x7fd18f2fc220) at kernel.cc:1395 #9 0x0000000000ad9bcc in execute_backup_command (thd=0x7fd1881f2cb8, lex=0x7fd1881f4588, backupdir=0x7fd18f2fd1a0, overwrite=false, skip_gap_event=false) at kernel.cc:269 #10 0x000000000068549f in mysql_execute_command (thd=0x7fd1881f2cb8) at sql_parse.cc:2482 #11 0x000000000068d0cf in mysql_parse (thd=0x7fd1881f2cb8, inBuf=0x2deb850 "BACKUP DATABASE testdb_N TO '/tmp/gentest8496-1259752997.14649-0.295562722390549.tmp'", length=85, found_semicolon=0x7fd18f2fdf00) at sql_parse.cc:5985 #12 0x000000000068dd38 in dispatch_command (command=COM_QUERY, thd=0x7fd1881f2cb8, packet=0x7fd1881fd829 "BACKUP DATABASE testdb_N TO '/tmp/gentest8496-1259752997.14649-0.295562722390549.tmp' ", packet_length=86) at sql_parse.cc:1078 #13 0x000000000068f2aa in do_command (thd=0x7fd1881f2cb8) at sql_parse.cc:760 #14 0x000000000067bff8 in handle_one_connection (arg=0x7fd1881f2cb8) at sql_connect.cc:1164 #15 0x000000315b0073da in start_thread () from /lib64/libpthread.so.0 #16 0x000000315a4e627d in clone () from /lib64/libc.so.6 strace reports an infinite progression of read calls [pid 8497] read(87, ""..., 1048575) = 0 meaning that EOF is being returned by read() but does not cause BACKUP to give up. The file descriptor 87 is connected to var/tmp/#sql210a_8_0-backuplog, which has a file size of zero. How to repeat: If this is repeatable, a test case will be provided. In the meantime, the core and the binary will be made available.