MySQL Bugs: #58282: "mtr --mem" does not work on a machine with libaio installed

Bug #58282	"mtr --mem" does not work on a machine with libaio installed
Submitted:	18 Nov 2010 10:38	Modified:	20 Dec 2010 3:08
Reporter:	Alexander Barkov	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Tools: MTR / mysql-test-run	Severity:	S3 (Non-critical)
Version:	mysql-5.5-bugteam	OS:	Linux (Fedora)
Assigned to:	Bjørn Munch	CPU Architecture:	Any
Tags:	regression

Description:
"mtr --mem" does not work if libaio is installed.

After uninstaling 'libaio-devel' and 'libaio' RPMs
and rebuilding 'mtr --mem' works fine.

How to repeat:
# Make sure libaio is installed:

$rpm -qa|grep libaio
libaio-devel-0.3.106-3.2
libaio-0.3.106-3.2

./BUILD/compile-pentium-debug-max

cd mysql-test
./mtr --mem func_str

> - symlinking 'var' to '/dev/shm/var_auto_nHwh'
> Installing system database...
> mysql-test-run: *** ERROR: Error executing mysqld --bootstrap

tail var/log/bootstrap.log

> 101118 10:50:14  InnoDB: Log file ./ib_logfile1 did not exist: new to be created
> InnoDB: Setting log file ./ib_logfile1 size to 5 MB
> InnoDB: Database physically writes the file full: wait...
101118 10:50:14  InnoDB: Operating system error number 22 in a file operation.
> InnoDB: Error number 22 means 'Invalid argument'.
> InnoDB: Some operating system error numbers are described at
> InnoDB: http://dev.mysql.com/doc/refman/5.1/en/operating-system-error-codes.html
> InnoDB: File name ./ib_logfile0
> InnoDB: File operation call: 'aio write'.
> InnoDB: Cannot continue operation.

Thank you for the report.

Verified as described. Version 5.1 is not affected.

Using --mem, you should turn native aio off: innodb_use_native_aio. It is on by default.

Perhaps MTR should do that? I guess it's a bit hard to deduce from a failed boostrap (with a invalid error message in the error log) that one can't run --mem with libaio installed.

Yes, it is better to be fixed in mtr. It is problematic for storage engine to detect which kind of file system is used.

It really fails with same error for test without --mem as well.

For my test for bug #58060 innodb_use_native_aio did not help.

It's not straightforward for mtr either to know if you're running on a memory file system. If you run mtr --mem it will create a softlink var to your vardir and if you run mtr again without --mem and it finds a var softlink, it will use that, whatever it points to. You may also override with --vardir=<path>.

You may of course also have your entire workspace in a memory file system.

Indeed, but special cases aside, at least for --mem it should be worth the effort to supply the command line to InnoDB.

Bug #58421 was marked as duplicate of this one.

I can reproduce the problem all right, but adding --skip-innodb-use-native-aio to the mysqld bootstrap command seems to have no effect? I get the exact same error:

---
InnoDB: Error: auto-extending data file ./ibdata1 is of a different size
InnoDB: 0 pages (rounded down to MB) than specified in the .cnf file:
InnoDB: initial 640 pages, max 0 (relevant if non-zero) pages!
InnoDB: Could not open or create data files.

I reopened Bug #58421 as not a duplicate of this. That is the core problem, this is a (partial) mtr workaround.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/126323

3123 Bjorn Munch	2010-12-08
      Bug #58282 "mtr --mem" does not work on a machine with libaio installed
      Workaround: add --loose-skip-innodb-use-native-aio
      Only on linux if explicitly using --mem or setting $OPT_MEM

Fine, as long as it gets removed once the original bug is fixed :-)

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/126416

3126 Bjorn Munch	2010-12-09
      Bug #58282 "mtr --mem" does not work on a machine with libaio installed
      Workaround: add --loose-skip-innodb-use-native-aio
      Only on linux if explicitly using --mem or setting $OPT_MEM

Pushed to 5.5-mtr, trunk-mtr

Pushed into mysql-5.5 5.5.9 (revid:georgi.kodinov@oracle.com-20101217124733-p1ivu6higouawv8l) (version source revid:bjorn.munch@oracle.com-20101209195322-embe21sfutgb3oy0) (merge vers: 5.5.8) (pib:24)

Pushed into mysql-trunk 5.6.1 (revid:georgi.kodinov@oracle.com-20101217125013-y8pb3az32rtbplc9) (version source revid:anitha.gopi@sun.com-20101210041312-50t9adyhwwybsm6x) (merge vers: 5.6.1) (pib:24)

Changes to test suite. No changelog entry needed.