"control file sequential read" wait during RAC Benchmark ?

From: VIVEK_SHARMA <VIVEK_SHARMA_at_infosys.com>
Date: Tue, 27 Feb 2007 18:37:07 +0530
Message-ID: <BBD944BCAC3AB4499DFBAFB1D8AF302002A49976@BLRKECMSG11.ad.infosys.com>

Folks

During internal 2 Node RAC Benchmark OLTP Nature Transaction Runs, following are the TOP Events from Statspack.

Qs 1) How can the "control file sequential read" wait be reduced after identifying the respective "busy" Objects?

Qs 2) Should Transactions be grouped Logically so that Transactions Hit different Data Blocks on the 2 Nodes?

Top 5 Timed Events
Avg %Total

---

wait Call

Event                                            Waits    Time (s)

(ms) Time

• ------------ ----------- ------ ------

CPU time                                                        12

43.6

control file sequential read                    21,969           7

0 25.4

reliable message                                    35           4

113 14.1

db file parallel write                           2,486           1

1 5.2

row cache lock                                     154           1

4 2.2

---

From the Manual:-

control file sequential read

Reading from the controlfile. This happens in many cases. For example, while:

• making a backup of the controlfiles
• sharing information (between instances) from the controlfile
• reading other blocks from the controlfiles
• reading the header block

Wait Time: The wait time is the elapsed time of the read.

Parameters:

file#

The controlfile from which the session is reading.

block#

Block number in the controlfile from where the session starts to read. The block size is the physical block size of the port (usually 512 bytes, some UNIX ports have 1 or 2 Kilobytes).

blocks

The number of blocks that the session is trying to read.

Configuration

10gR2

Solaris 10

Veritas CFS 5.0

Banking Product

Will Share Statspack etc with anybody

Cheers

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Received on Tue Feb 27 2007 - 07:07:07 CST