| Bug #60939 | Infinite loop in shutdown with dedicated purge threads | ||
|---|---|---|---|
| Submitted: | 21 Apr 2011 3:31 | Modified: | 27 Apr 2011 2:40 |
| Reporter: | Laurynas Biveinis (OCA) | Email Updates: | |
| Status: | Duplicate | Impact on me: | |
| Category: | MySQL Server: InnoDB storage engine | Severity: | S2 (Serious) |
| Version: | 5.6.2 | OS: | Linux |
| Assigned to: | CPU Architecture: | Any | |
[21 Apr 2011 3:32]
Laurynas Biveinis
GDB backtraces
Attachment: 60939-backtraces.txt (text/plain), 13.88 KiB.
[21 Apr 2011 3:32]
Laurynas Biveinis
This could be duplicate of http://bugs.mysql.com/bug.php?id=58868 , but I have no way of telling.
[22 Apr 2011 14:40]
Valeriy Kravchuk
Let's assume this is a duplicate of bug #58868 for now.
[27 Apr 2011 2:40]
Laurynas Biveinis
This issue becomes unobservable with the patch applied that removes purge coordinator sleeps.
[27 Apr 2011 2:42]
Laurynas Biveinis
Patch to remove purge sleeps
Attachment: 5.6-purge-fix.patch (text/x-diff), 748 bytes.
[27 Apr 2011 5:52]
Sunny Bains
Hi, In the latest version of the unreleased code there are no sleeps. The code is now similar to the way 5.5 purge thread works, using os_event_t. Regards, -sunny
Description: Server with innodb_fast_shutdown=0 and innodb_purge_threads=4 enters infinite loop in purge coordinator thread if there is a significant purge lag on shutdown. The error log shows many copies of the following message: 110420 20:06:11 InnoDB: Waiting for master thread to be suspended Thread 5 (full GDB backtraces in attachment) is looping around waiting for purge workers to complete, but there are no purge workers running. (gdb) print srv_get_task_queue_length() $1 = 3 (gdb) print purge_sys->n_executing $3 = 0 (gdb) print purge_sys->n_submitted $4 = 264148 (gdb) print purge_sys->n_completed $5 = 264145 Thread 5 (Thread 0x4a12b940 (LWP 32483)): #0 0x0000003fcc4cd212 in select () from /lib64/libc.so.6 #1 0x00000000009210af in os_thread_sleep (tm=<value optimized out>) at /data/laurynas/upstream/mysql-5.6.2-m5/storage/innobase/os/os0thread.c:274 #2 0x00000000008648c5 in trx_purge_wait_for_workers_to_complete (n_purge_threads=4, batch_size=20) at /data/laurynas/upstream/mysql-5.6.2-m5/storage/innobase/trx/trx0purge.c:1164 #3 trx_purge (n_purge_threads=4, batch_size=20) at /data/laurynas/upstream/mysql-5.6.2-m5/storage/innobase/trx/trx0purge.c:1288 #4 0x000000000085968d in srv_purge_coordinator_thread (arg=<value optimized out>) at /data/laurynas/upstream/mysql-5.6.2-m5/storage/innobase/srv/srv0srv.c:2831 #5 0x0000003fccc0673d in start_thread () from /lib64/libpthread.so.0 #6 0x0000003fcc4d3f6d in clone () from /lib64/libc.so.6 How to repeat: In description.