MaxDB memory allocation doubts

[Former Member]

Hi,

I installed the MaxDB 7.6.2.10 on IBM System x3400 with 5GB of RAM, and one Intel Xeon QuadCore processor installed, with Red Hat Enterprise Linux 5 and kernell 2.6.18-8.1.6.el5PAE.

i tried to configure CACHE_SIZE to use 2GB of RAM with that i get many messages like:

2007-07-16 11:54:41 3184 ERR 8 RTEMem No more system pages for 134221824 bytes available,BYTE_SIZE=4096,DESCRIPTION=posix_memalign,ERRORTEXT=ENOMEM ? out

2007-07-16 11:54:41 3184 ERR 8 RTEMem of memory

2007-07-16 11:54:41 3184 ERR 11 RTEMem + Used 2673582080 bytes from system heap with a limit of system imposed limitation bytes,ALLOC_COUNT=519,FREE_CO

2007-07-16 11:54:41 3184 ERR 11 RTEMem + UNT=0,ERROR_COUNT=2,BYTES_MAX_USED=2807803904

2007-07-16 11:54:41 3184 ERR 8 RTEMem No more system pages for 134221824 bytes available,BYTE_SIZE=4096,DESCRIPTION=posix_memalign,ERRORTEXT=ENOMEM ? out

2007-07-16 11:54:41 3184 ERR 8 RTEMem of memory

2007-07-16 11:54:41 3184 ERR 11 RTEMem + Used 2672009216 bytes from system heap with a limit of system imposed limitation bytes,ALLOC_COUNT=519,FREE_CO

2007-07-16 11:54:41 3184 ERR 11 RTEMem + UNT=3,ERROR_COUNT=3,BYTES_MAX_USED=2807803904

2007-07-16 11:54:41 3184 ERR 54008 MEMORY TransContext T186 : could not allocate

2007-07-16 11:54:41 3184 ERR 54008 MEMORY memory

2007-07-16 11:54:41 3184 ERR 54008 MEMORY required : 134217744

2007-07-16 11:54:41 3184 ERR 54008 MEMORY allocated : 917504

2007-07-16 11:54:41 3184 ERR 54008 MEMORY supplement : 134221824

2007-07-16 11:54:41 3184 ERR 54008 MEMORY limit : -1

then i changed the CACHE_SIZE to 1GB the errors above goes out but in database messages i get some messages:

Used memory exceeds physical memory installed (970 MBytes)

from what place the MaxDB see that 970 MBytes since the system have 5GB of RAM? and how i can increase CACHE_SIZE and dont have that allocation errors?

thanks for any idea.

Clóvis

[markus_doehr2 · Accepted solution]

Do you use a 32bit operating system and database kernel?

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Markus

[Former Member · Accepted solution]

hi Markus,

yes, all 32 bit follow more info:

2007-07-19 08:21:32 2452 12600 VERSION 'Kernel 7.6.02 Build 010-121-148-818'

2007-07-19 08:21:32 2452 12600 VERSION 'X32/LINUX 7.6.02 Build 010-121-148-818'

2007-07-19 08:21:32 2452 12781 INFO Version: '32BIT Kernel'

2007-07-19 08:21:32 2452 12781 INFO Version: 'X32/LINUX 7.6.02 Build 010-121-148-818'

2007-07-19 08:21:32 2452 12781 INFO Version: 'FAST'

2007-07-19 08:21:32 2452 12806 INFO Machine: 'i686'

2007-07-19 08:21:32 2452 12784 INFO Processors: 1 ( logical: 4, cores: 4 )

best regards

Clóvis

[markus_doehr2 · Accepted solution]

On a 32bit operating system processes can't allocate more than 2 GB.

You can, however, extend that with PAE (Physical Adress Extension), you use the correct kernel - but unfortunately MaxDB 7.6 does no more support PAE/AWE - and I'm not sure, if it was ever supported on other operating systems than Windows.

What processor do you use? (cat /proc/cpuinfo)

--

Markus

[Former Member · Accepted solution]

Hi, Markus

I configured first time CACHE_SIZE to use only 2GB but the MaxDB cant allocate that, this is because i must calculate the limit of 2GB with the size of CAT_CACHE_SUPPLY? iow the 2GB limit is the sum of CACHE_SIZE and CAT_CACHE_SUPPLY?

and about that message that physical memory its only 970 MBytes?

about the processor its a Intel Xeon QuadCore, follow the cpuinfo, just paste the first core info, the other are same:

processor : 0

vendor_id : GenuineIntel

cpu family : 6

model : 15

model name : Intel(R) Xeon(R) CPU E5310 @ 1.60GHz

stepping : 7

cpu MHz : 1596.038

cache size : 4096 KB

physical id : 0

siblings : 4

core id : 0

cpu cores : 4

fdiv_bug : no

hlt_bug : no

f00f_bug : no

coma_bug : no

fpu : yes

fpu_exception : yes

cpuid level : 10

wp : yes

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pni monitor ds_cpl vmx tm2 cx16 xtpr lahf_lm

bogomips : 3193.47

thanks

Clóvis

[markus_doehr2 · Accepted solution]

> I configured first time CACHE_SIZE to use only 2GB

> but the MaxDB cant allocate that, this is because i

> must calculate the limit of 2GB with the size of

> CAT_CACHE_SUPPLY? iow the 2GB limit is the sum of

> CACHE_SIZE and CAT_CACHE_SUPPLY?

yes - amongst others (number of MAXUSERTASKS, PACKETSIZE etc.)

> and about that message that physical memory its only

> 970 MBytes?

That is an "overflow" in a 32bit arithmethic... It's just diagnostics and does not lead to an error...

> about the processor its a Intel Xeon QuadCore, follow

> the cpuinfo, just paste the first core info, the

> other are same:

>

> processor : 0

> vendor_id : GenuineIntel

> cpu family : 6

> model : 15

> model name : Intel(R) Xeon(R) CPU

> E5310 @ 1.60GHz

> : 7

> z : 1596.038

> cache size : 4096 KB

> physical id : 0

> siblings : 4

> core id : 0

> cpu cores : 4

> fdiv_bug : no

> hlt_bug : no

> f00f_bug : no

> coma_bug : no

> fpu : yes

> fpu_exception : yes

> cpuid level : 10

> wp : yes

> flags : fpu vme de pse tsc msr pae mce cx8

> apic sep mtrr pge mca cmov pat pse36 clflush dts acpi

> mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pni

> monitor ds_cpl vmx tm2 cx16 xtpr lahf_lm

You CPU is 64bit capable, so I HIGHLY suggest installing a 64bit RHEL 5 (x86_64 - NOT IA-64) to circumvent all those issues you're actually facing.

--

Markus