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Thread: checkpoint hang in 7.2b4

checkpoint hang in 7.2b4

From
mlw
Date:
I was running a stock 7.2b4 Postgres with pgbench.

RedHat Linux 7.2, stock everything.
Dual PIII 650MHZ
SMP kernel
1G RAM
EXT3 file system

Adaptec SCSI disks, one for /base and ont for/pg_xlog

pgbench scaled to 50

./pgbench -n -t 100 -h $HOST -c 100 bench

It hung in the checkpoint. I wasn't able to trace it.

Re: checkpoint hang in 7.2b4

From
Tom Lane
Date:
mlw <markw@mohawksoft.com> writes:
> ./pgbench -n -t 100 -h $HOST -c 100 bench

> It hung in the checkpoint. I wasn't able to trace it.

Hung, or just took longer than you expected?

I don't see how you expect us to do anything with that report.
I can assure you I've run quite a few pgbenches on stock RH 
Linux 7.2, with no sign of a problem.  So you'll have to do some
investigation of your own, if you see a problem...
        regards, tom lane

Re: checkpoint hang in 7.2b4

From
mlw
Date:
Tom Lane wrote:
> 
> mlw <markw@mohawksoft.com> writes:
> > ./pgbench -n -t 100 -h $HOST -c 100 bench
> 
> > It hung in the checkpoint. I wasn't able to trace it.
> 
> Hung, or just took longer than you expected?

No, hung, 20 minutes. Load average dropped to zero.

> 
> I don't see how you expect us to do anything with that report.
> I can assure you I've run quite a few pgbenches on stock RH
> Linux 7.2, with no sign of a problem.  So you'll have to do some
> investigation of your own, if you see a problem...

Hey I didn't have the debugger going, I was doing a performance test. I will
look into it if it happens again. This wasn't a request for help, it was a
heads up. If what I saw was anomalous that's great, but if it isn't I want to
make sure that you guys heard about it, just in case.

Re: checkpoint hang in 7.2b4

From
Hannu Krosing
Date:
mlw wrote:
> 
> I was running a stock 7.2b4 Postgres with pgbench.
> 
> RedHat Linux 7.2, stock everything.
> Dual PIII 650MHZ
> SMP kernel
> 1G RAM
> EXT3 file system
> 
> Adaptec SCSI disks, one for /base and ont for/pg_xlog
> 
> pgbench scaled to 50
> 
> ./pgbench -n -t 100 -h $HOST -c 100 bench
> 
> It hung in the checkpoint. I wasn't able to trace it.

I had a similar experience once with -c 5. I sent output of 
"ps ax| grep post" to this list and Tom claimed it to be 
fixed in CVS head.

------------
Hannu

Re: checkpoint hang in 7.2b4

From
Tom Lane
Date:
Hannu Krosing <hannu@tm.ee> writes:
>> It hung in the checkpoint. I wasn't able to trace it.

> I had a similar experience once with -c 5. I sent output of 
> "ps ax| grep post" to this list and Tom claimed it to be 
> fixed in CVS head.

Oh, you're thinking of that three-way deadlock condition.  I've
forgotten, was that in b4?
        regards, tom lane

Re: checkpoint hang in 7.2b4

From
Hannu Krosing
Date:
On Sat, 2002-01-12 at 21:21, Tom Lane wrote:
> Hannu Krosing <hannu@tm.ee> writes:
> >> It hung in the checkpoint. I wasn't able to trace it.
> 
> > I had a similar experience once with -c 5. I sent output of 
> > "ps ax| grep post" to this list and Tom claimed it to be 
> > fixed in CVS head.
> 
> Oh, you're thinking of that three-way deadlock condition.  I've
> forgotten, was that in b4?

Yes.

--------------
Hannu