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slow response what is causing it.?

Rushank
Super Advisor

slow response what is causing it.?

Hello,
Env : N-class,HP11, Phy Mem: 8G
DB : Oracle 8i, one instance running, table space size more than 275 GB

The scenario:

A script runs every night to execute hot-backup.
Script compress the table spaces and copy it to a different file system within the system.
This entire process usually takes 5 hours but since last two weeks it takes more than 11 hours. In the past rebooting the server eliminated this problem for a month then it gradually becomes slow and hotbackup runs for a longer time
1. I would like to find out why it is happenning and what is causing it and why
reboot fixes it for initial few days.

2. User telnet to a different box and access database from N-box. How do we ralate broken link sessions between two servers.?

3. What are these oracleprod (LOCAL=NO) processs


Also atttached file is the output of sar -u sar -d, vmstat and output of process list sorted on vsz


Any help/suggetions appriciated.

Thanks
7 REPLIES
Roger Baptiste
Honored Contributor

Re: slow response what is causing it.?

The scenario:

A script runs every night to execute hot-backup. Script compress the table spaces and copy it to a different file system within the system.

>> So, does this mean that you are using
>> compress and copy command for backup's.

This entire process usually takes 5 hours but since last two weeks it takes more than 11 hours.

>> What is the amount of data being copied ?
>> Where does the destination filesystem reside??

1. I would like to find out why it is happenning and what is causing it and why
reboot fixes it for initial few days.

>> This can be best known by monitoring the
process as it occurs. See how long the
compress takes, how long the copy takes place.
Where is it being blocked on?

2. User telnet to a different box and access database from N-box. How do we ralate broken link sessions between two servers.?

>> I don't think this has anything to do
with user links.

3. What are these oracleprod (LOCAL=NO) processs

>> There are oracle sessions started by
users from PC's or non-local sources.


-raj

Take it easy.
Bill McNAMARA_1
Honored Contributor

Re: slow response what is causing it.?

what state is your file system in.. do you defrag it?
bdf

You appear to have some disks relatively heavily used..

You could perhaps try to redistribute your lvols..


strings /etc/lvmtab
to examine which vg is affected with the heavy hit pvs

and mount -p / lvdisplay to examine fs's affected.

That's just to start..
I'm sure you'll have the oracle experts on it in no time!

Later,
Bill
It works for me (tm)
Roger Baptiste
Honored Contributor

Re: slow response what is causing it.?

<>

Was this list taken, when the backup process
was running? (9:48) I see only two minutes of data and there is no cp/tar/compress or backup related command in the process list.

Is this backup being taken on a tape or is
it being written to another filesystem?
If it is another filesystem, then check
what physical devices it has.
(lvdisplay -v /dev/vg*/lvname)
and look at the sar -d stats for those devices.

-raj
Take it easy.
Rushank
Super Advisor

Re: slow response what is causing it.?

Rajman.,

The output of sar and vmstat were during the hotbackup but ps is not.
Script uses compress and cp command .
during hotbackup compress takes most of the cpu time (more than 50%)

Few disks are having bottlenecks I'm working on them.
My question why reboot fixes
Rushank
Super Advisor

Re: slow response what is causing it.?


Ooops..

And files are being copied within the system to a different file system
Roger Baptiste
Honored Contributor

Re: slow response what is causing it.?



The sar and vmstat values seems ok, except
that some disks on the sar output show high loads. (you would need to check them)

<Script uses compress and cp command .
during hotbackup compress takes most of the cpu time (more than 50%) >

Is this for an export backup? In that case,
if you are compressing and sending data
through a pipe, you would need to look at that too.



are you certain that the reboot actually
brought down the backup time?? (the same amount, same time etc). If the reboot
seemed to have fixed it, then i think it
has more to do with the database.
Instead of doing a reboot, shutdown and bring
up the database to confirm this.

You would need to drill the DBA to get more
details on the db end.

-raj
Take it easy.
Rushank
Super Advisor

Re: slow response what is causing it.?

Thanks Rajman,



If you see the process list there are many oracleprod (LOCAL=NO) process and I checked with lsof for a perticular process looks like eating up more resource.

DB says these process initiated by user but not sure about current activity could be broken link from the source server where actualy user logs in.
How can I separate out such process is the question.

Attached is the processes sorted on cpu utilization during hotbackup

Thanks