| Bug #35477 | sort_union() leaks file descriptors whenever goes over sort_buffer | ||
|---|---|---|---|
| Submitted: | 21 Mar 2008 11:10 | Modified: | 1 May 2008 1:52 |
| Reporter: | Domas Mituzas | Email Updates: | |
| Status: | Duplicate | Impact on me: | |
| Category: | MySQL Server: General | Severity: | S2 (Serious) |
| Version: | 5.0-bk, 5.1.24, 6.0 | OS: | Any |
| Assigned to: | Assigned Account | CPU Architecture: | Any |
| Tags: | fd leak, memory leak | ||
[21 Mar 2008 11:18]
Domas Mituzas
example dump file
Attachment: jtest.sql.gz (application/x-gzip, text), 465.77 KiB.
[21 Mar 2008 11:22]
Domas Mituzas
This bug got a brother at #35478 - it also returns invalid data
[26 Mar 2008 23:43]
Domas Mituzas
My amateurish fix, seems to handle the situation without too much crashing, and doesn't leak FDs. Bug#35478 still there, though: flute:~/Development/mysql-5.0/sql midom$ diff -U 7 filesort.cc filesort.cc.fixed --- filesort.cc 2008-03-27 01:41:17.000000000 +0200 +++ filesort.cc.fixed 2008-03-27 01:41:08.000000000 +0200 @@ -553,14 +553,15 @@ if (quick_select) { /* index_merge quick select uses table->sort when retrieving rows, so free resoures it has allocated. */ end_read_record(&read_record_info); + free_io_cache(select->quick->head); } else { (void) file->extra(HA_EXTRA_NO_CACHE); /* End cacheing of records */ if (!next_pos) file->ha_rnd_end(); }
[27 Mar 2008 6:20]
Domas Mituzas
patch seems to pass testsuite
[27 Mar 2008 9:34]
Domas Mituzas
This bug also leaks memory: ==18833== 66,073 (510 direct, 65,563 indirect) bytes in 6 blocks are definitely lost in loss record 6 of 7 ==18833== at 0x4022765: malloc (vg_replace_malloc.c:149) ==18833== by 0x831A874: my_malloc (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x8219CFF: Unique::get(st_table*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x824B166: QUICK_INDEX_MERGE_SELECT::read_keys_and_merge() (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x825B5AD: find_all_keys(st_sort_param*, SQL_SELECT*, unsigned char**, st_io_cache*, st_io_cache*, st_io_cache*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x825D7A8: filesort(THD*, st_table*, st_sort_field*, unsigned, SQL_SELECT*, unsigned long, unsigned long*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x81F56A4: create_sort_index(THD*, JOIN*, st_order*, unsigned long, unsigned long) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x8201904: JOIN::exec() (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x8203AE7: mysql_select(THD*, Item***, TABLE_LIST*, unsigned, List<Item>&, Item*, unsigned, st_order*, st_order*, Item*, st_order*, unsigned long long, select_result*, st_select_lex_unit*, st_select_lex*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x820436E: handle_select(THD*, st_lex*, select_result*, unsigned long) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x81AC028: mysql_execute_command(THD*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x81B14BB: mysql_parse(THD*, char const*, unsigned, char const**) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== ==18833== ==18833== 818,984 bytes in 4 blocks are possibly lost in loss record 7 of 7 ==18833== at 0x4022765: malloc (vg_replace_malloc.c:149) ==18833== by 0x831A874: my_malloc (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x825AA8F: init_read_record(st_read_record*, THD*, st_table*, SQL_SELECT*, int, bool) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x824B1A9: QUICK_INDEX_MERGE_SELECT::read_keys_and_merge() (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x825B5AD: find_all_keys(st_sort_param*, SQL_SELECT*, unsigned char**, st_io_cache*, st_io_cache*, st_io_cache*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x825D7A8: filesort(THD*, st_table*, st_sort_field*, unsigned, SQL_SELECT*, unsigned long, unsigned long*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x81F56A4: create_sort_index(THD*, JOIN*, st_order*, unsigned long, unsigned long) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x8201904: JOIN::exec() (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x8203AE7: mysql_select(THD*, Item***, TABLE_LIST*, unsigned, List<Item>&, Item*, unsigned, st_order*, st_order*, Item*, st_order*, unsigned long long, select_result*, st_select_lex_unit*, st_select_lex*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x820436E: handle_select(THD*, st_lex*, select_result*, unsigned long) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x81AC028: mysql_execute_command(THD*) (in /usr/local/mysql-5.0/libexec/mysqld) ==18833== by 0x81B14BB: mysql_parse(THD*, char const*, unsigned, char const**) (in /usr/local/mysql-5.0/libexec/mysqld)
[27 Mar 2008 9:39]
Domas Mituzas
slightly better formatted valgrind output at: http://p.defau.lt/?_ZxrNXcfnAPoKHSYrgqQSw
[27 Mar 2008 12:03]
Domas Mituzas
Fix for memory leak:
--- opt_range.cc 2008-03-27 08:03:13.000000000 -0400
+++ opt_range.cc.new 2008-03-27 08:03:04.000000000 -0400
@@ -1035,14 +1035,16 @@
QUICK_RANGE_SELECT* quick;
DBUG_ENTER("QUICK_INDEX_MERGE_SELECT::~QUICK_INDEX_MERGE_SELECT");
quick_it.rewind();
while ((quick= quick_it++))
quick->file= NULL;
quick_selects.delete_elements();
delete pk_quick_select;
+ if (&read_record)
+ end_read_record(&read_record);
free_root(&alloc,MYF(0));
DBUG_VOID_RETURN;
}
QUICK_ROR_INTERSECT_SELECT::QUICK_ROR_INTERSECT_SELECT(THD *thd_param,
TABLE *table,
[4 Apr 2008 13:54]
Georgi Kodinov
Domas, I've tried with the latest 5.0-opt-bk and I'm not getting the effect (no leaked fds) even after repeating the query several times. But I'm probably missing something in recreating the problem. Can we please get a real test script (for mysqltest) that uses e.g. INSERT INTO t1 ... SELECT ... FROM t1 ... to generate data (as looking at your test data dump this seems doable) ?
[4 Apr 2008 14:35]
MySQL Verification Team
Georgi, I haven't tested this, but you can try setting the lowest possible sort_buffer_size and see if it leaks then.
[10 Apr 2008 7:20]
MySQL Verification Team
standalone testcase to show 20MB/s memory leak, and file handle leak -------------------------------------------------------------------- delimiter ; drop table if exists `bug35477`; create table `bug35477` (`a` varchar(255),`b` varchar(255),`c` varchar(255),key(`a`),key(`b`),key(`c`)) engine=myisam; insert into `bug35477`values ('1','2','3'),('4','5','6'),('7','8','9'); set @a=1,@b=1,@c=1; insert into `bug35477` select @a:=@a+1,@b:=@b+2,@c:=@c+3 from `bug35477` a,`bug35477` b,`bug35477` c; insert into `bug35477` select @a:=@a+1,@b:=@b+2,@c:=@c+3 from `bug35477` a,`bug35477` b,`bug35477` c; drop procedure if exists `p_bug35477`; delimiter // create procedure `p_bug35477`(`numtimes` int) begin declare `i` int default '0'; repeat select * from `bug35477` where `a` like '5%' or `b` like '5%' order by `c` limit 1 into @a,@b,@c; if(`i` % 100 =0) then select `i` as repetition; end if; set `i`=`i`+1; until `i`>`numtimes` end repeat; end// delimiter ; set session sort_buffer_size=1024; call `p_bug35477`(50000);
[10 Apr 2008 12:11]
MySQL Verification Team
Georgi, if my above testcase doesn't repeat the problem on your internal BK builds, i wonder if this bug was fixed in bug #27732 (Possible memory leak with index_merge) ?
[10 Apr 2008 14:17]
Sergey Petrunya
Using 5.0-opt with tip cset: ChangeSet@1.2601, 2008-03-27 20:05:51+04:00, gshchepa@host.loc +2 -0 Merge host.loc:/home/uchum/work/mysql-5.0 into host.loc:/home/uchum/work/5.0-opt MERGE: 1.2599.1.2 (i.e. BUG#27732 is in the tree), I still can see the fd leaks.
[10 Apr 2008 14:42]
Sergey Petrunya
Can observe leaks on the latest 6.0 opt also. tip cset: ChangeSet@1.2604, 2008-04-07 13:21:26-06:00, malff@lambda.hsd1.co.comcast.net. +1 -0 Merge malff@bk-internal.mysql.com:/home/bk/mysql-5.0-opt into lambda.hsd1.co.comcast.net.:/home/malff/TREE/mysql-5.0-35658 MERGE: 1.2598.5.1
[10 Apr 2008 14:43]
Sergey Petrunya
The above two observations were made by using Domas's testcase
[21 Apr 2008 4:21]
Sergey Petrunya
The fix is at http://lists.mysql.com/commits/45739
[1 May 2008 1:52]
Sergey Petrunya
Fixed by fix for BUG#35478. Changing status to duplicate.
[22 Jul 2008 18:36]
Bugs System
Pushed into 5.0.68
[28 Jul 2008 13:46]
Bugs System
Pushed into 5.0.68 (revid:kpettersson@mysql.com-20080716141220-83aobe5fdgd9ye5l) (pib:2) (Retry automatic marking, to ensure nothing is missed. cm01)
[28 Jul 2008 14:45]
Bugs System
Pushed into 6.0.7-alpha (revid:alik@mysql.com-20080725172155-fnc73o50e4tgl23k) (version source revid:alik@mysql.com-20080725172155-fnc73o50e4tgl23k) (pib:3)
[28 Jul 2008 16:44]
Bugs System
Pushed into 5.1.28 (revid:davi.arnaut@sun.com-20080722182431-0i2f1yc4uocime9q) (version source revid:davi.arnaut@sun.com-20080722182431-0i2f1yc4uocime9q) (pib:3)
[14 Sep 2008 2:21]
Bugs System
Pushed into 6.0.7-alpha (revid:sergefp@mysql.com-20080715141321-2vlk93j5blqa7kxe) (version source revid:sven@mysql.com-20080818195835-r615g9zz6xphmkzg) (pib:3)
Description: whenever sort_union() is used, and sort_buffer_size is reached, temporary files are leaked: mysqld 3988 mysql 122u REG 14,2 78654 16999463 /private/var/tmp/MY69MtDm mysqld 3988 mysql 123u REG 14,2 78654 16999469 /private/var/tmp/MYuUS218 mysqld 3988 mysql 124u REG 14,2 78654 16999475 /private/var/tmp/MYXTIgLK mysqld 3988 mysql 125u REG 14,2 78654 16999481 /private/var/tmp/MYhnvrNz mysqld 3988 mysql 126u REG 14,2 78654 16999487 /private/var/tmp/MYXAYcoG mysqld 3988 mysql 127u REG 14,2 78654 16999493 /private/var/tmp/MYhOGRAZ mysqld 3988 mysql 128u REG 14,2 78654 16999499 /private/var/tmp/MY1RLE4Q mysqld 3988 mysql 129u REG 14,2 78654 16999505 /private/var/tmp/MYwXVR6D mysqld 3988 mysql 130u REG 14,2 78654 16999511 /private/var/tmp/MYh8SGBC How to repeat: CREATE TABLE `jtest` ( `a` varchar(255) default NULL, `b` varchar(255) default NULL, `c` varchar(255) default NULL, KEY `a` (`a`), KEY `b` (`b`), KEY `c` (`c`) ) ENGINE=MyISAM fill with few megabytes of random data, so that hitting sort buffer problems would be easier set sort_buffer_size=10000; then loop: select * from jtest where a like '5%' or b like '5%' order by c limit 1; mysql> explain select * from jtest where a like '5%' or b like '5%' order by c limit 1 \G *************************** 1. row *************************** id: 1 select_type: SIMPLE table: jtest type: index_merge possible_keys: a,b key: a,b key_len: 258,258 ref: NULL rows: 23746 Extra: Using sort_union(a,b); Using where; Using filesort 1 row in set (0.00 sec) Suggested fix: close the files?