Concurrent Query Execution

[antexity]

Hi,

I have a couple questions running reports concurrently as I don't have much experience in Concurrent execution.

Currently our C8.4 is in sequential settings (I assume),

We have a report that has queries that needs to be ran at the same time if not our summary portion of our report differs from out detailed information.

If I enable Concurrent using IBM information from their manual:

Set Parameters for Concurrent Query Execution
By default, Cognos 8 executes queries in a report sequentially. Depending on your environment,
you may be able to improve report run performance by enabling concurrent query execution. You can do this by setting advanced server properties for the report service, the batch report service, or both. When concurrent query execution is enabled, the report server determines which queries in the report can be run concurrently.

The report author must specify the queries in a report that are candidates for concurrent
execution. For more information, see the Report Studio User Guide.
Parameter Purpose
RSVP.CONCURRENTQUERY.
NUMHELPERSPERPROCESS
Enables concurrent query execution and sets the maximum
number of query execution helpers for each report service or
batch report service process.
Each query execution helper results in an additional data
source connection. For example, a report service has four
processes with two high affinity connections and two low
affinity connections:
• If the maximum number of query execution helpers is set
to 0 (disabled), the maximum number of data source
connections created by the report service is 16 (two low
affinity connections plus two high affinity connections
plus zero query execution helpers times four processes).
• If the maximum number of query execution helpers is set
to 2, the maximum number of data source connections
created by the report service is 24 (two low affinity
connections plus two high affinity connections plus two
query execution helpers times four processes).
The calculated maximum number of data source connections
applies to each report service or batch report service process.
Default: 0 (concurrent query execution disabled)
RSVP.CONCURRENTQUERY.
MAXNUMHELPERSPERREPORT
The maximum number of query execution helpers for each
report. Use this property to prevent a single report from
consuming all available query execution helpers. For
example, a report has eight queries that can run concurrently:
• If RSVP.CONCURRENTQUERY.NUMHEL
PERSPERPROCESS and RSVP.
CONCURRENTQUERY.MAXNUMHELPERSPER
REPORT are both set to four, the report consumes all
query helpers when executed. No other report is able to
run queries concurrently until the report has finished
executing.
• If RSVP.CONCURRENTQUERY.MAXNUM
HELPERSPERREPORT is set to two instead, the report
consumes two query helpers, leaving two for other
reports to use.
Default: 1
This setting has no effect unless
RSVP.CONCURRENTQUERY.NUMHELPERSPER
PROCESS is set to greater than 0.
72
Chapter 4: Server Administration
To access the server administration tool, you must have execute permissions for the server
administration secured feature and traverse permission for the Administration secured function.
Steps
1. In Cognos Connection, in the upper-right corner, click Tools, Server Administration.
2. Click the Monitor tab.
3. Select the Services option.
4. Click the set properties button for the Report or the Batch Report service.
5. Click the Settings tab.
6. Click Edit next to Advanced Settings.
7. Select Override the settings acquired from the parent entry.
8. In the Parameter column, enter a parameter name.
9. In the Value column, enter the setting that you want to use.
10. Click OK.
11. On the Set properties page, click OK.


=====================================================

By enabling the parameters is that a global change on how all the reports will be ran in the future, or if I want to run a report concurrently after enabling these parameters, Do I have to edit the report specifically to have the queries run concurrently? (I hope this is the case because I don't want to affect on how the other reports run)

I'm also assuming enabling Concurrent will increase my performance greatly?

One last question, whoever has this enabled,  what settings do I change for each parameter, I have no clue and I have no clue what Query helpers are?

These are the parameters :

• RSVP.CONCURRENTQUERY.NUMHELPERSPERPROCESS
• RSVP.CONCURRENTQUERY.
  MAXNUMHELPERSPERREPORT
• RSVP.CONCURRENTQUERY.
  ENABLEDFORINTERACTIVEOUTPUT

Type of Report:

Labor Efficiency report, currently with 5 queries, maybe a couple more in the future,   in Lists and some graphs (see attached (since its one attachment per post I just combined them in one screenshot))


THANK YOU SO MUCH,

Jonathan

[redmist]

Jonathan

i believe that would be a global change although i could be wrong.

Since i was not clear on how this change would affect the performance, i turn on concurrent query processing in Report Studio

This can be done in RS by setting the Execution Method property of the query

[antexity]

Hi Redmist,

Thanks for the reply,

So I don't have to change any parameters,  I can go right to the report and open in Report Studio, and go to the Execution method and change to Concurrent and do that for each query and it will work?

Thanks,
Jonathan

[RobsWalker68]

Hi Jonathan,

You still have to set the parameters for the report or batch service otherwise the concurrent execution will remain disabled.  Once it has been enabled then in Report Studio you can choose which queries are candidates for concurrent execution.

Most probably need to point out that even marking a query as a candidate for concurrent execution doesn't mean that Cognos will actually execute it concurrently.

Rgds

Rob

[antexity]

Thanks Rob,

To clarify, once I set the parameters, there is no change at all in the system until I do the manual change per report as well Could you please assist me , which values I need to set per parameter?

As well,  what would not make a report a candidate for concurrent execution?

Thanks Again,
Jonathan

[RobsWalker68]

Hi Jonathan,

I've never had to use it in a commercial environment so haven't got a set of values to recommend I'm afraid but for RSVP.CONCURRENTQUERY.NUMHELPERSPERPROCESS perhaps start at 1 and then monitor any effect or impact and increase by an increment of 1.  Hopefully someone else may be able to recommend a setting.

IBM don't seem to say explicitly what would not make a query a candidate for concurrent execution, although I would imagine it is similar to a database hint.  A database optimiser may use a hint unless it identifies it can do it a quicker way by not using it.

Rgds

Rob   

[antexity]

Hi,

If anyone has Concurrent Queries setup, please let me know,  I just need to know how to setup the parameters specifically.

Thank you so much,
Jonathan

[Arsenal]

I believe the following document will be of great use to you and will answer the system level prompt settings questions you have, including optimal settings

http://public.dhe.ibm.com/software/dw/dm/cognos/reporting/performance_and_tuning/advanced_prompting.pdf

[antexity]

Awesome, more to sleep... i mean read  :P

Thank you very much,  I gave it a quick review and should have some good information.  A Monday job.

Thanks,
Jonathan