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db cfg: CATALOGCACHE_SZ obscurites.

This is a discussion on db cfg: CATALOGCACHE_SZ obscurites. within the DB2 forums, part of the Database Server Software category; --> Hello there. 1) According to documentation, setting CATALOGCACHE_SZ = -1 means CATALOGCACHE_SZ = (MAXAPPLS*4) But MAXAPPLS is set to ...


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  #1 (permalink)  
Old 02-27-2008, 01:42 PM
Konstantin Andreev
 
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Default db cfg: CATALOGCACHE_SZ obscurites.

Hello there.

1) According to documentation, setting
CATALOGCACHE_SZ = -1 means CATALOGCACHE_SZ = (MAXAPPLS*4)

But MAXAPPLS is set to AUTOMATIC, this means "no limit" or "no value". Again, according to documentation, CATALOGCACHE_SZ is allocated "when the database is initialized". Hence, I'm interesting, which value is really allocated instead of illusion (<no limit>*4).

"get db cfg" command does not help here, because literally displays "(MAXAPPLS*4)".

2) There would be no room for question (1) if I have a way to reliably check CATALOGCACHE_SZ value. But I have inconsistent results:
_______________________________________________
| |CATALOG | "catcacheh" (token of db2mtrk -d)
MAXAPPLS|CACHE_SZ| shown | I would expect...
--------+--------+--------+--------------------
(ignore) 100 192,0K 4K*100 = 400K
20 -1 64,0K 4K*(20*4) = 320K
AUTOMAT -1 64,0K (no assumptions)
-----------------------------------------------

Hence, I'm intresting, how are related CATALOGCACHE_SZ db config parameter, "catcacheh" token of db2mtrk, and real catalog cache size ?
--
Konstantin Andreev.
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  #2 (permalink)  
Old 02-27-2008, 01:42 PM
Jan M. Nelken
 
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Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Konstantin Andreev wrote:
> Hello there.
>
> 1) According to documentation, setting
> CATALOGCACHE_SZ = -1 means CATALOGCACHE_SZ = (MAXAPPLS*4)
>
> But MAXAPPLS is set to AUTOMATIC, this means "no limit" or "no
> value". Again, according to documentation, CATALOGCACHE_SZ is allocated
> "when the database is initialized". Hence, I'm interesting, which value
> is really allocated instead of illusion (<no limit>*4).


AUTOMATIC does not mean "no limit" or "no value".

Did you try DB2 GET DB CFG FOR <alias> SHOW DETAIL?


Jan M. Nelken
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  #3 (permalink)  
Old 02-27-2008, 01:42 PM
The Boss
 
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Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Konstantin Andreev wrote:
> Hello there.
>
> 1) According to documentation, setting
> CATALOGCACHE_SZ = -1 means CATALOGCACHE_SZ = (MAXAPPLS*4)
>
> But MAXAPPLS is set to AUTOMATIC, this means "no limit" or "no
> value". Again, according to documentation, CATALOGCACHE_SZ is
> allocated "when the database is initialized". Hence, I'm interesting,
> which value is really allocated instead of illusion (<no limit>*4).


AUTOMATIC doesn't mean "no limit" or "no value", it means the value is
determined by DB2 and dynamically adapted depending on circumstances.

>
> "get db cfg" command does not help here, because literally
> displays "(MAXAPPLS*4)".


Try the autoconfigure command instead, with the no-apply option, like this:

db2 autoconfigure using MAXAPPLS CATALOGCACHE_SZ apply none

It will show both the formula and the actual value.

HTH.

--
Jeroen


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  #4 (permalink)  
Old 02-27-2008, 01:42 PM
Konstantin Andreev
 
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Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Thank everybody!

> AUTOMATIC does not mean "no limit" or "no value". Did you try DB2 GET DB CFG FOR <alias> SHOW DETAIL?


"Show detail", of course! I've absolutely forgotten it.
--
Konstantin Andreev.
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  #5 (permalink)  
Old 02-27-2008, 01:42 PM
Jan M. Nelken
 
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Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Konstantin Andreev wrote:

> "Show detail", of course! I've absolutely forgotten it.


You could also use:

db2pd -db <alias> -dbcfg

and grep (or find) keyword you need:


For orthodox Windows believers:

db2pd -db sample -dbcfg | find /i "maxappls"


For progressive Windows believers (who downloaded grep for Windows) and
Unix followers:

db2pd -db smple -dbcfg | grep -i maxappls


Jan M. Nelken
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  #6 (permalink)  
Old 02-27-2008, 01:42 PM
Konstantin Andreev
 
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Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Jan M. Nelken wrote:

> You could also use:
> db2pd -db <alias> -dbcfg


db2pd is my postponed headache. It just exits silently in my system. No complains/error messages, exit code is always zero, and random command line arguments does not change this ("db2pdcfg" behaves the same). So I should leave without it.

> For progressive Windows believers (who downloaded grep for Windows)
> db2pd -db smple -dbcfg | grep -i maxappls


For everybody, who has wrote more than one or two scripts for Windows, installing a proper set of unix utilities under Windows is a must. sed, awk, grep,... all are should be here.
--
Konstantin Andreev.
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  #7 (permalink)  
Old 02-27-2008, 01:42 PM
Jan M. Nelken
 
Posts: n/a
Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Konstantin Andreev wrote:

> db2pd is my postponed headache. It just exits silently in my system. No
> complains/error messages, exit code is always zero, and random command
> line arguments does not change this ("db2pdcfg" behaves the same). So I
> should leave without it.


As the wise man said: We will not fix problems we don't know about...

Can you capture system calls trace on some trivial invocation of db2pd,
for example:

db2pd -db sample -dbcfg

Make sure you get this on supported Linux distribution - see
http://www-306.ibm.com/software/data...inux/validate/ for details.

For DB2 V9 32-bit platform this would be RHEL 4, RHEL 5, SLES 9, SLES 10
and Novell Open Enterprise Server 9.

For each of those distributions specific kernel level and/or libraries
levels may be required.

Jan M. Nelken
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  #8 (permalink)  
Old 02-27-2008, 01:43 PM
Konstantin Andreev
 
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Default Re: db cfg: CATALOGCACHE_SZ obscurites.

On Jun 4, 10:02 pm, "Jan M. Nelken" wrote:
> > db2pd is my postponed headache. It just exits silently in my system. No complains/error messages, exit code is always zero, and random command line arguments does not change this.


> As the wise man said: We will not fix problems we don't know about...


Certainly...
>
> Can you capture system calls trace on some trivial invocation of db2pd, for example:
>
> db2pd -db sample -dbcfg

| avalon ~ # strace db2pd -db psftprod -dbcfg 2>&1 | wc -l
| 445

It's a lot of output, I am not sure, is it appropriate to post the
trace to group? The traces are identical (accurate within memory
addresses) on invocations of db2pd with random arguments. The most
suspicios call is third preceding exit:

| access("/db2/srv/dbi/sqllib/lib/libdb2fmtdmp.so", F_OK) = -1 ENOENT
| setuid32(0) = 0
| exit_group(0) = ?

I've checked the DB2 v9 installation pack, there is no such file in
it.

> Make sure you get this on supported Linux distribution


Too bad, I have only one installation of v9, and this linux distro
(gentoo) is not officially supported. If your time permits analyzing
this problem, I gratefully supply any required details (kernel,
libraries, and so on...).

I believe this in not distro related problem. Most likely, some simple
misconfiguration.
--
Konstantin Andreev.

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  #9 (permalink)  
Old 02-27-2008, 01:43 PM
Jan M. Nelken
 
Posts: n/a
Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Konstantin Andreev wrote:

> It's a lot of output, I am not sure, is it appropriate to post the
> trace to group? The traces are identical (accurate within memory
> addresses) on invocations of db2pd with random arguments. The most
> suspicios call is third preceding exit:
>
> | access("/db2/srv/dbi/sqllib/lib/libdb2fmtdmp.so", F_OK) = -1 ENOENT
> | setuid32(0) = 0
> | exit_group(0) = ?
>
> I've checked the DB2 v9 installation pack, there is no such file in
> it.


Please also run this:

db2pd -v -debug db2pddbg

and include db2pddbg file with strace output.
You can uplaod compressed output to ftp server:

ftp.software.ibm.com

into directory

/ps/toibm/db2

as file:

stuuf4jun.gz

and I will have a look.


As for libdb2fmtdmp.so - this library is used for formatting internal
data structures. On customer systems internal data are written as hex dump.
This library is not needed in your case - it's not shipped to customers.


Jan M. Nelken

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  #10 (permalink)  
Old 02-27-2008, 01:44 PM
Konstantin Andreev
 
Posts: n/a
Default Re: db cfg: CATALOGCACHE_SZ obscurites.

Jan M. Nelken wrote:

>> It's a lot of output, I am not sure, is it appropriate to post the trace to group?


> You can uplaod compressed output to ftp server:
> ftp.software.ibm.com
> into directory
> /ps/toibm/db2



| # ftp ftp://ftp.software.ibm.com/
| Current remote directory is /.
| ncftp / > cd /ps/toibm/db2
| Could not chdir to /ps/toibm/db2: server said: toibm: No such file or directory.


I've overlooked the /ps directory, but could not find something simular to 'toibm'. Looks like you mistyped the URL
--
Konstantin Andreev.
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