Re: streams capture performance
- From: "Madhu Sreeram" <madhusreeram@xxxxxxxxx>
- To: "Bradd Piontek" <piontekdd@xxxxxxxxx>
- Date: Wed, 15 Oct 2008 21:13:21 -0500
min_parallel_servers=0
max_parallel_servers=80
data from dba_capture_parameters:
==========================
Capture_Name..................: V_CAPTURE
Parameter.....................: DISABLE_ON_LIMIT
Value.........................: N
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: DOWNSTREAM_REAL_TIME_MINE
Value.........................: Y
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: MAXIMUM_SCN
Value.........................: INFINITE
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: MESSAGE_LIMIT
Value.........................: INFINITE
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: PARALLELISM
Value.........................: 4
Set_By_User...................: YES
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: STARTUP_SECONDS
Value.........................: 0
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: TIME_LIMIT
Value.........................: INFINITE
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: TRACE_LEVEL
Value.........................: 0
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: WRITE_ALERT_LOG
Value.........................: Y
Set_By_User...................: NO
-----------------
Capture_Name..................: V_CAPTURE
Parameter.....................: _CHECKPOINT_FREQUENCY
Value.........................: 1000
Set_By_User...................: YES
-----------------
the value of streams_pool_size is set 256m but the SGA_TARGET is 8Gb so, I
expect it would grow bigger, if needed.
redo log file is 200mb each. Log switch varies between less than a min to
12mins .
-thanks
On Wed, Oct 15, 2008 at 8:50 PM, Bradd Piontek <piontekdd@xxxxxxxxx> wrote:
> Can you post what the settings are in dba_capture_parameters?
> As for init.ora:
> min_parallel_servers
> max_parallel_servers
> (i would increase the streams_pool_size)
>
> How big are your redo logs and how often, on average, to do switches occur?
>
> Bradd Piontek
> "Next to doing a good job yourself,
> the greatest joy is in having someone
> else do a first-class job under your
> direction."
> -- William Feather
>
>
>
> On Wed, Oct 15, 2008 at 5:38 PM, Madhu Sreeram <madhusreeram@xxxxxxxxx>wrote:
>
>> Hi all,
>>
>>
>> I have a question about the performance expectation of streams capture
>> process. I just implemented streams to capture DML changes in certain tables
>> in our production and am not happy with the performance. If it doesn't
>> improve we will be falling back to triggers. The capture latency is about
>> 12hrs (capture process is reading 12hrs back archive file). Ours is a very
>> high rate transaction database ( ~ 400gb/day archives). Based on the strmmon
>> output during day (night time is more busy):
>>
>>
>> Streams Pool Size = 256M
>> LOG 169K (redo/sec)
>> Capture rate: about 2400 lcrs captured per sec, about 4 lcrs enqueued/sec
>> <idle wait events percentage> <flow control wait events percentage>: <90%I
>> 0%F
>>
>> Env: 10.2.0.4 on Redhat linux 4.1. six node RAC. Each node is two dual
>> core AMD Opteron processors (64bit). Capture is local.
>>
>> I am not concerned with "APPLY" rate , yet, as changes to apply is
>> expected to be low. I am only concerned with the captured rate.
>>
>>
>> I have already looked at the best practices docs and made suitable
>> changes. Oracle support analyst says that's the best I can get (he has not
>> provided any reference documents yet) but I want to know from users who
>> have implemented Streams. Are the numbers above fairly high? Is streams not
>> designed for such a high log generation? What has been your experience?
>>
>> Thanks in advance.
>>
>> -Madhu Sreeram
>>
>>
>
Other related posts:
