Percona server 5.5 completely stalls during import (myloader)

Bug #1519094 reported by Mischa ter Smitten on 2015-11-23
This bug affects 1 person
Affects Status Importance Assigned to Milestone
MySQL Server
Percona Server moved to
Fix Released
Laurynas Biveinis
Fix Released
Laurynas Biveinis
Fix Released
Laurynas Biveinis

Bug Description

The problem seem to be caused by: innodb_adaptive_flushing_method = keep_average, innodb_adaptive_flushing_method = estimate runs stable.

description: updated

Output of:

gdb -ex "set pagination 0" -ex "thread apply all bt" --batch -p $(pidof mysqld)

Unfortunately some of the symbol information is missing in gdb dump, does the server have debug info packages installed?

No, how does that work? Installing the percona-server-5.5-dbg package and then what?

Please just retry the gdb command after having the package installed.

I will do that.

Output of:

gdb -ex "set pagination 0" -ex "thread apply all bt" --batch -p $(pidof mysqld)

With percona-server-5.5-dbg installed

Thanks. I am analysing the dump.

Did this started happening after an upgrade? If yes, can you tell the latest PS 5.5 version which worked for you?

Hard to say, it's on new hardware, new installation.

On our previous setup we never encountered the problem (in our normal workload). But we never do mass imports there and we also have different hardware there so it's hard to compare...

tags: added: i62298

Mischa and everybody experiencing random hangs on 5.5.46 / 5.6.27, please test server build with a preliminary fix, available at:


(please click through the blue dots to navigate to the right packages for your system).

Please confirm whether with these packages the problem does not occur anymore. In case it still does, please repeat the previous procedure: 1) make sure the debug info package is installed; 2) get the server to hanged state; 3) execute "gdb -ex "set pagination 0" -ex "thread apply all bt" --batch -p $(pidof mysqld)" and post here its output.

I'll try to test them today.

Is there any reason why I would need to avoid using innodb_adaptive_flushing_method = keep_average on non SSD cards.

On our machines we have:
* single SSD
* multiple SSD, software RAID
* multiple SSD, hardware RAID

But non of them have SSD cards.

I assume this is asked in the context of the current bug, i.e. why keep_average causes this hang. But it's not keep_average itself which is the cause of the bug (if the fix is confirmed), but rather increased mutex pressure. The bug has probability of appearing with any adaptive flushing setting.

Yes, in the context of the current bug.

We don't have the problem when we use innodb_adaptive_flushing_method = estimate and when using innodb_adaptive_flushing_method = keep_average on MariaDB.

If our analysis is correct then 1) the bug has a probability of appearing with any innodb_adaptive_flushing_method on Percona Server, just some more likely than others 2) MariaDB is not affected with any innodb_adaptive_flushing_method.

We will post the final bug analysis after we have confirmations that the issue disappeared.

I've had 52 successful imports (before patch not more than +/- 5) last night so it looks like it fixed our problem.

tags: added: innodb upstream
Yura Sorokin (yura-sorokin) wrote :

Fixed by Oracle in 5.5.49, 5.6.30 and 5.7.12.

5.5 commit: 93e6f38

Percona now uses JIRA for bug reports so this bug report is migrated to:

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