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BUG#11751793 - 42784: ARCHIVE TABLES CAUSE 100% CPU USAGE

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AND HANG IN SHOW TABLE STATUS.

ISSUE: Table corruption due to concurrent queries.
       Different threads running insert and check
       query leads to table corruption. Not properly locked,
       rows are inserted in between check query.

SOLUTION: In check query mutex lock is acquired
          for a longer time to handle concurrent
          insert and check query.

NOTE: Additionally we backported the fix for CHECKSUM
      issue(bug#11758979).
This commit is contained in:
Ashish Agarwal 2011-11-23 18:33:29 +05:30
parent 82a5902f07
commit 75c08c7935
3 changed files with 72 additions and 9 deletions
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19
mysql-test/r/archive.result
View file

@ -12772,3 +12772,22 @@ a b c d e f
-1 b c d e 1
DROP TABLE t1;
SET sort_buffer_size=DEFAULT;
#
# BUG#11758979 - 51252: ARCHIVE TABLES CAUSE 100% CPU USAGE
# AND HANG IN SHOW TABLE STATUS
# (to be executed with valgrind)
CREATE TABLE t1(a BLOB, b VARCHAR(200)) ENGINE=ARCHIVE;
INSERT INTO t1 VALUES(NULL, '');
FLUSH TABLE t1;
# we need this select to workaround BUG#11764364
SELECT * FROM t1;
a b
NULL
CHECKSUM TABLE t1 EXTENDED;
Table Checksum
test.t1 286155052
FLUSH TABLE t1;
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
DROP TABLE t1;

14
mysql-test/t/archive.test
View file

@ -1693,3 +1693,17 @@ INSERT INTO t1 SELECT t1.* FROM t1,t1 t2,t1 t3,t1 t4,t1 t5,t1 t6;
SELECT * FROM t1 ORDER BY f LIMIT 1;
DROP TABLE t1;
SET sort_buffer_size=DEFAULT;
--echo #
--echo # BUG#11758979 - 51252: ARCHIVE TABLES CAUSE 100% CPU USAGE
--echo # AND HANG IN SHOW TABLE STATUS
--echo # (to be executed with valgrind)
CREATE TABLE t1(a BLOB, b VARCHAR(200)) ENGINE=ARCHIVE;
INSERT INTO t1 VALUES(NULL, '');
FLUSH TABLE t1;
--echo # we need this select to workaround BUG#11764364
SELECT * FROM t1;
CHECKSUM TABLE t1 EXTENDED;
FLUSH TABLE t1;
OPTIMIZE TABLE t1;
DROP TABLE t1;

48
storage/archive/ha_archive.cc
View file

@ -760,6 +760,7 @@ uint32 ha_archive::max_row_length(const uchar *buf)
ptr != end ;
ptr++)
{
if (!table->field[*ptr]->is_null())
length += 2 + ((Field_blob*)table->field[*ptr])->get_length();
}
@ -1110,6 +1111,17 @@ int ha_archive::unpack_row(azio_stream *file_to_read, uchar *record)
/* Copy null bits */
const uchar *ptr= record_buffer->buffer;
/*
Field::unpack() is not called when field is NULL. For VARCHAR
Field::unpack() only unpacks as much bytes as occupied by field
value. In these cases respective memory area on record buffer is
not initialized.
These uninitialized areas may be accessed by CHECKSUM TABLE or
by optimizer using temporary table (BUG#12997905). We may remove
this memset() when they're fixed.
*/
memset(record, 0, table->s->reclength);
memcpy(record, ptr, table->s->null_bytes);
ptr+= table->s->null_bytes;
for (Field **field=table->field ; *field ; field++)
@ -1578,13 +1590,15 @@ int ha_archive::check(THD* thd, HA_CHECK_OPT* check_opt)
{
int rc= 0;
const char *old_proc_info;
ha_rows count= share->rows_recorded;
ha_rows count;
DBUG_ENTER("ha_archive::check");
old_proc_info= thd_proc_info(thd, "Checking table");
/* Flush any waiting data */
pthread_mutex_lock(&share->mutex);
azflush(&(share->archive_write), Z_SYNC_FLUSH);
count= share->rows_recorded;
/* Flush any waiting data */
if (share->archive_write_open)
azflush(&(share->archive_write), Z_SYNC_FLUSH);
pthread_mutex_unlock(&share->mutex);
if (init_archive_reader())
@ -1594,18 +1608,34 @@ int ha_archive::check(THD* thd, HA_CHECK_OPT* check_opt)
start of the file.
*/
read_data_header(&archive);
for (ha_rows cur_count= count; cur_count; cur_count--)
{
if ((rc= get_row(&archive, table->record[0])))
goto error;
}
/*
Now read records that may have been inserted concurrently.
Acquire share->mutex so tail of the table is not modified by
concurrent writers.
*/
pthread_mutex_lock(&share->mutex);
count= share->rows_recorded - count;
if (share->archive_write_open)
azflush(&(share->archive_write), Z_SYNC_FLUSH);
while (!(rc= get_row(&archive, table->record[0])))
count--;
thd_proc_info(thd, old_proc_info);
pthread_mutex_unlock(&share->mutex);
if ((rc && rc != HA_ERR_END_OF_FILE) || count)
{
share->crashed= FALSE;
DBUG_RETURN(HA_ADMIN_CORRUPT);
}
goto error;
thd_proc_info(thd, old_proc_info);
DBUG_RETURN(HA_ADMIN_OK);
error:
thd_proc_info(thd, old_proc_info);
share->crashed= FALSE;
DBUG_RETURN(HA_ADMIN_CORRUPT);
}
/*