Re: received more blocks than served?

From: 조동욱 <ukja.dion_at_gmail.com>
Date: Tue, 8 Jul 2008 09:03:16 +0900
Message-ID: <43c2e3d60807071703s805f60ya8a8e60ebf71904c@mail.gmail.com>


Can you compare the result
- with the total summation of "received" and "served" blocks, including cr blocks?
- and with the summation of cr blocks only?

Dion Cho

2008/7/8 <dannorris_at_dannorris.com>:

> I have a 3-node 10.2.0.3 RAC cluster on RH4. I was looking for
> verification that I hadn't dropped any blocks between instances during GC
> operations. So, I wanted to get a sum of all blocks sent, a sum of all
> blocks received and they should be very close to equal.
>
> What I see below has me perplexed. How can there be more blocks received
> than served? That is, how can an instance receive more information than
> was sent? Can a single block be served to multiple destinations? I don't
> think so, but maybe that's where the magical block synthesis is coming
> from?
>
> It's a 3-node cluster, so there's no easy 1-to-1 mapping to be done.
>
> I'm open for ideas...
>
> 1 select sum(b2.value) "GCS CURR BLOCKS RECEIVED",
> 2 sum(b1.value) "GCS CURR BLOCKS SERVED",
> 3 (sum(b1.value)-sum(b2.value)) "SERVED - RECEIVED"
> 4 from gv$sysstat b1, gv$sysstat b2
> 5 where b1.name = 'gc current blocks served'
> 6 and b2.name = 'gc current blocks received'
> 7* and b1.inst_id = b2.inst_id
>
> GCS CURR BLOCKS RECEIVED GCS CURR BLOCKS SERVED SERVED - RECEIVED
> ------------------------ ---------------------- --------------------
> 628072519 622037942 -6034577
>
> Dan
>
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

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Received on Mon Jul 07 2008 - 19:03:16 CDT

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