SQL Clone
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Alpha character in SPID? Disk I\O Bottleneck Troubleshooting.


Alpha character in SPID? Disk I\O Bottleneck Troubleshooting.

Author
Message
Adam_Smasher
Adam_Smasher
Valued Member
Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)

Group: General Forum Members
Points: 69 Visits: 20
Hi.

OS is Server 2003 R2 Enterprise Service Pack 2.
SQL is Microsoft SQL Server 2005 - 9.00.3353.00.

I was tasked with troubleshooting the following repeating error:

Source      spid4s

Message
SQL Server has encountered 30 occurrence(s) of I/O requests taking longer than 15 seconds to complete on file [C:\Program Files\Microsoft SQL Server\MSSQL.2\MSSQL\DATA\DataBase_data.mdf] in database [DataBase] (8). The OS file handle is 0x00000960. The offset of the latest long I/O is: 0x000000d80d8000


However, I don't know how to troubleshoot "spid4s".
What is the alpha character 's' doing in the spid?

There spid is just the session ID, right?
Session IDs only have numbers.
There is a session 4, but that's been asleep while the error has happened.
It's happened multiple times while I've watched it because of 'SPID4' which I can't even investigate.

Can anyone shed some light for me?
GilaMonster
GilaMonster
SSC Guru
SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)

Group: General Forum Members
Points: 219519 Visits: 46279
System process.
It's session_id 4 and the s marks it as a system process. So spid 56s would be some system process running on session_id 56

p.s. Session_id 4 was the one reporting the error, not the one causing the problem.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


Adam_Smasher
Adam_Smasher
Valued Member
Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)

Group: General Forum Members
Points: 69 Visits: 20
So, SPID4 is reporting the problem, not necessarily the cause of the problem?
SPID 4 is Lazy Writer.

Am I correct in assuming that because of the 'S' in the SPID that SPID 12 'CHECKPOINT' would be reported as '12S'?
Or is it the fact that it involves a Windows process that invokes the 'S'?
GilaMonster
GilaMonster
SSC Guru
SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)SSC Guru (219K reputation)

Group: General Forum Members
Points: 219519 Visits: 46279
Adam_Smasher (3/7/2013)
So, SPID4 is reporting the problem, not necessarily the cause of the problem?


Correct.

The slow IOs is telling you that in the last hour, there were x number of IO operations that took over 15 seconds to complete. Since IO operations should be measured in the ms, that's a slight problem. There's nothing in the message that can suggest which processes had slow IOs, just which file.

Am I correct in assuming that because of the 'S' in the SPID that SPID 12 'CHECKPOINT' would be reported as '12S'?


If the checkpoint had reason to write into the error log, the source column would be spid12s

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


Adam_Smasher
Adam_Smasher
Valued Member
Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)Valued Member (69 reputation)

Group: General Forum Members
Points: 69 Visits: 20
Thanks for the help.

I just wanted to let everyone know that I am looking to move the most heavily used database and the TempDB to another physical drive.
I haven't received confirmation from the application analyst when I can do this.
I will update this thread whatever the outcome when I can.
Nadrek
Nadrek
SSCarpal Tunnel
SSCarpal Tunnel (4.4K reputation)SSCarpal Tunnel (4.4K reputation)SSCarpal Tunnel (4.4K reputation)SSCarpal Tunnel (4.4K reputation)SSCarpal Tunnel (4.4K reputation)SSCarpal Tunnel (4.4K reputation)SSCarpal Tunnel (4.4K reputation)SSCarpal Tunnel (4.4K reputation)

Group: General Forum Members
Points: 4444 Visits: 2741
Make sure you get your physical hardware folks to check out the storage. A RAID controller cache battery going bad can cause the RAID card to disable its [write] cache, which can cause this. Network/FC issues, etc. for non-local storage can also have effects.
Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search