LevelDB Storage Engine MS2 (MDEV-4201)

[MDEV-4300] LevelDB: Server crashes in inline_mysql_mutex_lock on SELECT .. FOR UPDATE Created: 2013-03-19  Updated: 2013-03-26  Resolved: 2013-03-26

Status: Closed
Project: MariaDB Server
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Technical task Priority: Major
Reporter: Elena Stepanova Assignee: Sergei Petrunia
Resolution: Fixed Votes: 0
Labels: leveldb

Issue Links:
Relates

 Description    

CREATE TABLE t1 (pk INT PRIMARY KEY) ENGINE=LevelDB;
 
CREATE TABLE t2 (pk INT PRIMARY KEY, i INT, KEY (i)) ENGINE=LevelDB;
 
INSERT INTO t1 VALUES (1),(2);
 
INSERT INTO t2 VALUES (1,4),(2,5);
 
SELECT ( SELECT 1 FROM t1 ) FROM t2 WHERE i < 0 FOR UPDATE;
 

#3  <signal handler called>
 
#4  0x0000000000b0b7a6 in inline_mysql_mutex_lock (that=0xb5, src_file=0x102cb40 "mysql-5.6-leveldb/storage/leveldb/ldb_locks.cc", src_line=277) at mysql-5.6-leveldb/include/mysql/psi/mysql_thread.h:659
 
#5  0x0000000000b0c27c in LockTable::release_lock (this=0x17817a0, pins=0x7f969c038a40, own_lock=0x95) at mysql-5.6-leveldb/storage/leveldb/ldb_locks.cc:277
 
#6  0x0000000000b09303 in Ldb_transaction::release_last_lock (this=0x7f969c013fa0) at mysql-5.6-leveldb/storage/leveldb/ha_leveldb.cc:236
 
#7  0x0000000000b06937 in ha_leveldb::unlock_row (this=0x7f969c03e7a0) at mysql-5.6-leveldb/storage/leveldb/ha_leveldb.cc:1649
 
#8  0x0000000000621cd9 in handler::read_range_first (this=0x7f969c03e7a0, start_key=0x7f969c03e880, end_key=0x7f969c03e8a0, eq_range_arg=false, sorted=false) at mysql-5.6-leveldb/sql/handler.cc:6577
 
#9  0x0000000000620079 in handler::multi_range_read_next (this=0x7f969c03e7a0, range_info=0x7f96c065f5f0) at mysql-5.6-leveldb/sql/handler.cc:5732
 
#10 0x0000000000922d32 in QUICK_RANGE_SELECT::get_next (this=0x7f969c05ada0) at mysql-5.6-leveldb/sql/opt_range.cc:10407
 
#11 0x000000000093a952 in rr_quick (info=0x7f969c0403b0) at mysql-5.6-leveldb/sql/records.cc:367
 
#12 0x0000000000775c07 in join_init_read_record (tab=0x7f969c040320) at mysql-5.6-leveldb/sql/sql_executor.cc:2388
 
#13 0x0000000000773477 in sub_select (join=0x7f969c03f2a0, join_tab=0x7f969c040320, end_of_records=false) at mysql-5.6-leveldb/sql/sql_executor.cc:1249
 
#14 0x0000000000772f11 in do_select (join=0x7f969c03f2a0) at mysql-5.6-leveldb/sql/sql_executor.cc:936
 
#15 0x0000000000770f5e in JOIN::exec (this=0x7f969c03f2a0) at mysql-5.6-leveldb/sql/sql_executor.cc:191
 
#16 0x00000000007cbb85 in mysql_execute_select (thd=0x2545740, select_lex=0x2547f20, free_join=true) at mysql-5.6-leveldb/sql/sql_select.cc:1100
 
#17 0x00000000007cbe6a in mysql_select (thd=0x2545740, tables=0x7f969c006238, wild_num=0, fields=..., conds=0x7f969c006960, order=0x25480e8, group=0x2548020, having=0x0, select_options=2147748608, result=0x7f969c006b98, unit=0x25478e0, select_lex=0x2547f20) at mysql-5.6-leveldb/sql/sql_select.cc:1221
 
#18 0x00000000007c9fba in handle_select (thd=0x2545740, result=0x7f969c006b98, setup_tables_done_option=0) at mysql-5.6-leveldb/sql/sql_select.cc:110
 
#19 0x00000000007a6782 in execute_sqlcom_select (thd=0x2545740, all_tables=0x7f969c006238) at mysql-5.6-leveldb/sql/sql_parse.cc:4987
 
#20 0x000000000079f5f4 in mysql_execute_command (thd=0x2545740) at mysql-5.6-leveldb/sql/sql_parse.cc:2557
 
#21 0x00000000007a8be7 in mysql_parse (thd=0x2545740, rawbuf=0x7f969c004fd0 "SELECT ( SELECT 1 FROM t1 ) FROM t2 WHERE i < 0 FOR UPDATE", length=58, parser_state=0x7f96c0661110) at mysql-5.6-leveldb/sql/sql_parse.cc:6117
 
#22 0x000000000079c9a3 in dispatch_command (command=COM_QUERY, thd=0x2545740, packet=0x2618ca1 "", packet_length=58) at mysql-5.6-leveldb/sql/sql_parse.cc:1312
 
#23 0x000000000079bb66 in do_command (thd=0x2545740) at mysql-5.6-leveldb/sql/sql_parse.cc:1036
 
#24 0x0000000000766e09 in do_handle_one_connection (thd_arg=0x2545740) at mysql-5.6-leveldb/sql/sql_connect.cc:969
 
#25 0x000000000076682e in handle_one_connection (arg=0x2545740) at mysql-5.6-leveldb/sql/sql_connect.cc:885
 
#26 0x0000000000af6924 in pfs_spawn_thread (arg=0x249a920) at mysql-5.6-leveldb/storage/perfschema/pfs.cc:1853
 
#27 0x00007f96c1a7de9a in start_thread (arg=0x7f96c0662700) at pthread_create.c:308
 
#28 0x00007f96c0f98cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
 

revision-id: psergey@askmonty.org-20130319094846-yze9xy3qeb5g6hrc
 
revno: 4610
 
branch-nick: mysql-5.6-leveldb



 Comments   
Comment by Sergei Petrunia [ 2013-03-25 ]

A simpler testcase is possible: instead of

SELECT ( SELECT 1 FROM t1 ) FROM t2 WHERE i < 0 FOR UPDATE;

one can use

SELECT 1 FROM t2 WHERE i < 0 FOR UPDATE;

Comment by Sergei Petrunia [ 2013-03-25 ]

The cause of the bug seems to be that

  • SQL layer tells us to run index_only scan, which we do. index-only scans cannot do any locking.
  • SQL layer calls handler->unlock_row(), which tries to release the last row lock.. when the transaction doesn't have any locks. Crash.

IIRC, InnoDB had the same problem. SELECT .. FOR UPDATE ran index-only scans. InnoDB made them non-index-only under the hood. I'll investigate whether that is still true.

Comment by Sergei Petrunia [ 2013-03-25 ]

... No, they seem to lock index records, now.

Comment by Sergei Petrunia [ 2013-03-25 ]

#0 row_get_rec_trx_id (rec=0xabe1c5cb "\200", index=0x994d588, offsets=0xa6505ccc) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/include/row0row.ic:79
#1 0x087c6704 in lock_clust_rec_some_has_impl (rec=0xabe1c5cb "\200", index=0x994d588, offsets=0xa6505ccc) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/include/lock0priv.ic:64
#2 0x087d15d9 in lock_rec_convert_impl_to_expl (block=0xab7e3c80, rec=0xabe1c5cb "\200", index=0x994d588, offsets=0xa6505ccc) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/lock/lock0lock.cc:6024
#3 0x087d191a in lock_clust_rec_read_check_and_lock (flags=0, block=0xab7e3c80, rec=0xabe1c5cb "\200", index=0x994d588, offsets=0xa6505ccc, mode=LOCK_X, gap_mode=1024, thr=0x9945390) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/lock/lock0lock.cc:6349
#4 0x0889dd85 in row_sel_get_clust_rec_for_mysql (prebuilt=0x9944d90, sec_index=0x994dba0, rec=0xabdf81c0 "\200", thr=0x9945390, out_rec=0xa6505e9c, offsets=0xa6505e74, offset_heap=0xa6505e78, mtr=0xa6505ec4) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/row/row0sel.cc:3111
#5 0x0889ffad in row_search_for_mysql (buf=0x9931158 "\377", mode=2, prebuilt=0x9944d90, match_mode=0, direction=0) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/row/row0sel.cc:4682
#6 0x08789887 in ha_innobase::index_read (this=0x992f740, buf=0x9931158 "\377", key_ptr=0x98b8cb0 "", key_len=5, find_flag=HA_READ_KEY_OR_NEXT) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/handler/ha_innodb.cc:7398
#7 0x0823fed8 in handler::index_read_map (this=0x992f740, buf=0x9931158 "\377", key=0x98b8cb0 "", keypart_map=1, find_flag=HA_READ_KEY_OR_NEXT) at /home/psergey/dev2/mysql-5.6-leveldb/sql/handler.h:2203
#8 0x08230420 in handler::ha_index_read_map (this=0x992f740, buf=0x9931158 "\377", key=0x98b8cb0 "", keypart_map=1, find_flag=HA_READ_KEY_OR_NEXT) at /home/psergey/dev2/mysql-5.6-leveldb/sql/handler.cc:2668
#9 0x08234179 in handler::read_range_first (this=0x992f740, start_key=0x992f7e4, end_key=0x992f7f4, eq_range_arg=false, sorted=false) at /home/psergey/dev2/mysql-5.6-leveldb/sql/handler.cc:6576
#10 0x0822f9c2 in handler::multi_range_read_next (this=0x992f740, range_info=0xa65065b0) at /home/psergey/dev2/mysql-5.6-leveldb/sql/handler.cc:5747
#11 0x0823536b in DsMrr_impl::dsmrr_next (this=0x9931124, range_info=0xa65065b0) at /home/psergey/dev2/mysql-5.6-leveldb/sql/handler.cc:6106
#12 0x087728bc in ha_innobase::multi_range_read_next (this=0x992f740, range_info=0xa65065b0) at /home/psergey/dev2/mysql-5.6-leveldb/storage/innobase/handler/ha_innodb.cc:16427
#13 0x0857aaab in QUICK_RANGE_SELECT::get_next (this=0x98b8b78) at /home/psergey/dev2/mysql-5.6-leveldb/sql/opt_range.cc:10409
#14 0x085aaa57 in rr_quick (info=0x995ba4c) at /home/psergey/dev2/mysql-5.6-leveldb/sql/records.cc:367
#15 0x083ba89c in join_init_read_record (tab=0x995b9fc) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_executor.cc:2395
#16 0x083bc92a in sub_select (join=0x98b8d78, join_tab=0x995b9fc, end_of_records=false) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_executor.cc:1256
#17 0x083bd174 in do_select (join=0x98b8d78) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_executor.cc:941
#18 0x083beec9 in JOIN::exec (this=0x98b8d78) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_executor.cc:191
#19 0x0842100d in mysql_execute_select (thd=0x989f328, select_lex=0x98a0fc8, free_join=true) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_select.cc:1100
#20 0x08421a75 in mysql_select (thd=0x989f328, tables=0x98ba8c8, wild_num=0, fields=..., conds=0x994c838, order=0x98a10dc, group=0x98a1060, having=0x0, select_options=2148797184, result=0x994a708, unit=0x98a0b64, select_lex=0x98a0fc8) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_select.cc:1221
#21 0x084230b8 in handle_select (thd=0x989f328, result=0x994a708, setup_tables_done_option=0) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_select.cc:110
#22 0x083e872c in execute_sqlcom_select (thd=0x989f328, all_tables=0x98ba8c8) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_parse.cc:5019
#23 0x083ea89d in mysql_execute_command (thd=0x989f328) at /home/psergey/dev2/mysql-5.6-leveldb/sql/sql_parse.cc:2589
#24 0x083f2b91 in mysql_parse (thd=0x989f328, rawbuf=0x98bad88 "select 1 from t10 where a between 23 and 33 for update", length=54,

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