Re: RAC waitevent: gc freelist on one node

  • From: "Michael Elkin" <melkin4u@xxxxxxxxx>
  • To: guillermo.bort@xxxxxxx
  • Date: Mon, 3 Nov 2008 05:34:45 +0200

In Oracle 10.2 and 11g the following describes "global cache freelist" event
<<
global cache freelist

All releasable locks are used and a new one has been requested. To make a
resource element available, a resource element is pinged.

Wait Time: The duration of the resource get operation to ping the resource
element

>>

I think that LMS process does not fast enough to release locks.

Michael

On Fri, Oct 31, 2008 at 5:08 PM, Bort, Guillermo <guillermo.bort@xxxxxxx>wrote:

>  Not sure if it fits the case, but it's  worth taking a look at. From the
> RAC FAQ:
>
>
>
> What do I do if I see GC CR BLOCK LOST in my top 5 Timed Events in my AWR
> Report?
>
>
>
> You should never see this or BLOCK RETRY events. This is most likely due to
> a fault in your interconnect network. Work with your system administrator
> or/and network administrator to find the fault. Check netstat -s
>
>
>
> Ip:
>
> 84884742 total packets received
>
> 1201 fragments dropped after timeout
>
> 3384 packet reassembles failed
>
>
>
> You do not want to see fragments dropped or packet reassemblies failed.
>
>
>
> ifconfig -a:
>
>
>
> eth0 Link encap:Ethernet HWaddr 00:0B:DB:4B:A2:04
>
> inet addr:130.35.25.110 Bcast:130.35.27.255 Mask:255.255.252.0
>
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
>
> RX packets:21721236 errors:135 dropped:0 overruns:0 frame:95
>
> TX packets:273120 errors:0 dropped:0 overruns:0 carrier:0
>
>
>
> You do not want to see high number of errors.
>
>
>
> *Guillermo Alan Bort*
>
> DBA / DBA Main Team
>
>
>
> *EDS*, an HP company
>
>
>
> *From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto:
> oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *Ajay Thotangare
> *Sent:* Friday, October 31, 2008 12:48 PM
> *To:* oracle-l@xxxxxxxxxxxxx
> *Subject:* RAC waitevent: gc freelist on one node
>
>
>
> Hi,
>
> We have having a 3 node RAC and from last few days noticed performance of 1
> of node has degraded. In V$session session of that node, I always see lot of
> sessions waiting on waitevent "gc freelist". I don't see this wait event on
> other 2 nodes where performance is not affected.
>
> Not sure if this wait event is indicating something. I could not find any
> documentation on this wait event Can somebody please explain me this wait
> event or point me to right document. Does this wait event looks related to
> degraded performance?
>
> Pls advice.
>
> --Ajay
>
>
>



-- 
Best Regards
Michael Elkin

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