From: Matthias Hoys <matthias.h...@gmail.com>
Date: Tue, 15 May 2012 07:30:17 -0700 (PDT)
Local: Tues, May 15 2012 10:30 am
Subject: Re: Slower performance after enabling async io on Oracle Linux
On Tuesday, May 15, 2012 4:07:47 PM UTC+2, Matthias Hoys wrote:Problem solved: I saw the following in the listener.log file: "WARNING: Subscription for node down event still pending". The solution is to add "SUBSCRIBE_FOR_NODE_DOWN_EVENT_LISTENER=OFF" to the listener.ora file, and restart the listener. Apparently, the listener service constantly tries to contact a RAC service, but this is a non-RAC installation. It was already a known issue with Oracle 10g. Way to go, Oracle ;-) Let's see if this improves the async io performance.
> On Tuesday, May 15, 2012 3:16:46 PM UTC+2, Matthias Hoys wrote:
> > On Tuesday, May 15, 2012 2:52:33 AM UTC+2, Mladen Gogala wrote:
> > > Matthias, I the problem may as well lie on the network side. Check netstat
> > > -s for timeouts, retransmits or packets being dropped. Depending on the
> > > hardware, you may want to use jumbo packets, increase rmem and wmem
> > > parameters. Below are two articles about tuning the network:
> > > Problem with Linux is that it is not well instrumented, there is no wait
> > > So, if you want a recipe, measure the duration of the system calls by
> > Using netstat -s, I think I found something:
> > Tcp:
> > I'm no network specialist, but it seems like there are a huge amount of "failed connection attempts"?? Or is this normal for iSCSI, I never worked with iSCSI storage before...
> > Btw: we don't have a local disk, everything is on VMWare and the disks are on the iSCSI box.
> > Thanks for the help,
> Update: the Oracle Listener is causing all the "failed connection attempts". When I stop it, no more failed connection attempts. I'm now further debugging this...
You must Sign in before you can post messages.
To post a message you must first join this group.
Please update your nickname on the subscription settings page before posting.
You do not have the permission required to post.