Comment 5 for bug 643650

Yasufumi,

We can use new checksum from Facebook, they have implementation based
on CPU instructions.

Why do you need to check checksum at shutdown?

I am setting this as "high" because the purpose of feature is to
minimize downtime, and this bug makes it problematic.

On Tuesday, September 21, 2010, Yasufumi Kinoshita
<email address hidden> wrote:
> Anyway, calc check sum is needed to confirm destruction, I think.
> It should be changed to ut_fold_binary_32 of innodb_fast_checksum.patch?
> But it might make around 1/2 of the time.
>
> And why the importance of it is "High"?
> It doesn't break anything data. Not danger.
> No magic solutions.
>
> --
> InnoDB with shared buffer pool takes long to shutdown
> https://bugs.launchpad.net/bugs/643650
> You received this bug notification because you are a member of Percona
> developers, which is the registrant for Percona Server.
>
> Status in Percona Server with XtraDB: Confirmed
>
> Bug description:
> I noticed that on server with big amount of memory ( 120GB buffer pool)
> when I use buffer_pool_shared memory it takes very long to shutdown.
>
> There is some process after InnoDB finished flushing, it is CPU bound process.
>
> stack trace:
>
>
> (gdb) thread app all bt
>
> Thread 2 (Thread 0x599e2940 (LWP 17830)):
> #0  buf_pool_free () at ./include/ut0rnd.ic:224
> #1  0x0000000000798a3a in innobase_shutdown_for_mysql () at srv/srv0start.c:2215
> #2  0x000000000072c78f in innobase_end (hton=<value optimized out>, type=<value optimized out>) at handler/ha_innodb.cc:2588
> #3  0x000000000068f6ab in ha_finalize_handlerton (plugin=0x5725db8) at handler.cc:395
> #4  0x000000000070cbc6 in plugin_deinitialize (plugin=0x5725db8, ref_check=true) at sql_plugin.cc:828
> #5  0x000000000070d6fe in reap_plugins () at sql_plugin.cc:916
> #6  0x000000000070db8d in plugin_shutdown () at sql_plugin.cc:1551
> #7  0x00000000005b01bc in clean_up (print_message=true) at mysqld.cc:1363
> #8  0x00000000005b061e in unireg_end () at mysqld.cc:1289
> #9  0x00000000005b430d in kill_server (arg=<value optimized out>) at mysqld.cc:1224
> #10 kill_server_thread (arg=<value optimized out>) at mysqld.cc:1252
> #11 0x0000003d2760673d in start_thread () from /lib64/libpthread.so.0
> #12 0x0000003d26ed3d1d in clone () from /lib64/libc.so.6
>
> Thread 1 (Thread 0x2ab90c584fb0 (LWP 17698)):
> #0  0x0000003d2760aee9 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
> #1  0x00000000005b52f5 in main (argc=<value optimized out>, argv=<value optimized out>) at mysqld.cc:4765
>
>
>

--
Vadim Tkachenko, CTO, Percona Inc.
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