[mythtv-users] MySQL related BE deadlocks - collective wisdom needed

Warpme warpme at o2.pl
Sun Jul 24 13:11:15 UTC 2011


Hi,

I'm calling for collective wisdom of all mysql/Linux gurus here.
I have continuous BE deadlocks (despite my last comments in 9773/9772 
last 2 days were nightmare with 4 deadlocks).
Analyzing traces majority of them seems to point to common issue: hang 
within mysql libraries during myth access to DB).
Usually hung thread looks following:

Thread 9 (Thread 0x9e4ffb70 (LWP 13256)):
#0  0xb77c6424 in __kernel_vsyscall ()
#1  0xb676581b in read () from /lib/libpthread.so.0
#2  0xb1b6eba8 in vio_read () from /usr/lib/libmysqlclient_r.so.16
#3  0xb1b6ec0b in vio_read_buff () from /usr/lib/libmysqlclient_r.so.16
#4  0xb1b6fbb0 in ?? () from /usr/lib/libmysqlclient_r.so.16
#5  0xb1b7071b in my_net_read () from /usr/lib/libmysqlclient_r.so.16
#6  0xb1b69124 in cli_safe_read () from /usr/lib/libmysqlclient_r.so.16
#7  0xb1b3c8e9 in cli_read_prepare_result () from 
/usr/lib/libmysqlclient_r.so.16
#8  0xb1b3cc7a in mysql_stmt_prepare () from /usr/lib/libmysqlclient_r.so.16
#9  0xb1d08f78 in ?? () from /usr/lib/qt/plugins/sqldrivers/libqsqlmysql.so
#10 0xb64b36aa in QSqlResult::savePrepare(QString const&) () from 
/usr/lib/libQtSql.so.4
#11 0xb64a55e2 in QSqlQuery::prepare(QString const&) () from 
/usr/lib/libQtSql.so.4
#12 0xb6c87bdc in MSqlQuery::prepare (this=0x9e4feb40, query=...) at 
mythdbcon.cpp:757
#13 0xb740de84 in get_chan_id_from_db (sourceid=8, serviceid=13122, 
networkid=113, transportid=13200) at eithelper.cpp:805
#14 0xb740d8f2 in EITHelper::GetChanID (this=0x8d49800, serviceid=13122, 
networkid=113, tsid=13200) at eithelper.cpp:742
#15 0xb740b3b9 in EITHelper::AddEIT (this=0x8d49800, eit=0x9e4feee0) at 
eithelper.cpp:346
#16 0xb719e260 in DVBStreamData::HandleTables (this=0x9f5bb1f0, pid=18, 
psip=...) at mpeg/dvbstreamdata.cpp:376
#17 0xb717c4c1 in MPEGStreamData::HandleTSTables (this=0x9f5bb278, 
tspacket=0x9da53828) at mpeg/mpegstreamdata.cpp:935
#18 0xb717c914 in MPEGStreamData::ProcessTSPacket (this=0x9f5bb278, 
tspacket=...) at mpeg/mpegstreamdata.cpp:1010
#19 0xb717c658 in MPEGStreamData::ProcessData (this=0x9f5bb278, 
buffer=0x9da4e008 "G\001a\035\345H\032\221\315tE", <incomplete sequence 
\366>,
     len=26508) at mpeg/mpegstreamdata.cpp:960
#20 0xb750415c in DVBStreamHandler::RunTS (this=0x9e48678) at 
dvbstreamhandler.cpp:258
#21 0xb7502dcf in DVBStreamHandler::run (this=0x9e48678) at 
dvbstreamhandler.cpp:111
#22 0xb5673843 in ?? () from /usr/lib/libQtCore.so.4
#23 0xb675ec77 in start_thread () from /lib/libpthread.so.0
#24 0xb5446c6e in clone () from /lib/libc.so.6

In many traces lines 0...12 looks very similar.
I'm on ArchLinux. Sys is quite fresh (all packages refreshed 13/05).
Myth is latest master (compiled 2 days ago).
Issue was present with Arch stock 5.5.12 mysql packages.

I already:
-do mysql downgrade by fresh rebuild & reinstall mysql 5.1.57 (Also all 
mysql dependent packages were rebuilded/reinstall)
-backup/delete/initialize/restore myth DB
-turn-off completely MySQL query cache
-change DB schema from MyISAM to InnoDB
-turn-off all other apps using mysql

Unfortunately nothing from above list helps - I still have deadlocks 
(this weekend 4. Very frustrating).

I'll be really grateful for any hint helping me to move forward with 
this very frustrating situation.

br




-------------- next part --------------
A non-text attachment was scrubbed...
Name: warpme.vcf
Type: text/x-vcard
Size: 83 bytes
Desc: not available
Url : http://www.mythtv.org/pipermail/mythtv-users/attachments/20110724/f8f9d75d/attachment.vcf 


More information about the mythtv-users mailing list