Memory issues on Production system

[jsanghvi]

Hello,

We are facing memory dumps and slow SAP performance on our PRODUCTION ECC EHP4 system.

Many work process also goes to PRIV mode frequently

But we have very good response Time also.

I checked ST06 and see,

CPU Idle % = 40%

IO wait % = 16%

CPU count = 8

Number of request waiting to get processed in

1 Min = 7

5 Min = 6

15 Min = 6

We have Physical memory = 50GB

Free Memory only = 300 MB

We have following parameter set in RZ10

em/initial_size_MB = 4 GB

ztta/roll_extension = 2 GB

abap/heap_area_dia = 5GB

abap/heap_area_nondia = 5GB

abap/heap_area_total = 10 GB

rdisp/wp_no_dia                             20

rdisp/wp_no_btc                             8

Please guide

Regards,

[jsanghvi]

Hello,

I increased the Extended Memory to 16Gb

And decreased the Heap memory by 2Gb

So for now, As I check over Two weeks , I dont have any Wp's in PRIV mode.

Thanks,

Jigar

[former_member4224]

To avoid PRIV mode you should increase the Extend Memory areas.

Regards

Clebio Dossa

[Former Member]

First investigate your storage subsystem performance. Can you provide output of vmstat command?

[former_member193518]

What memory dumps?

Check ST02 also.

Thanks.

[ACE-SAP]

Hello

Having workprocess getting into priv mode is not always a problem, the bad point is that the workprocess is then dedicated to the current user.

It can get worst f the user keeps it's trnasaction open for a very long time and keep the workprocess stuck...

With the configuration you have that means that the process has already allocated 6Gb of memory, this is quite a lot but not insane.

This is really becoming a problem if you have many process stuck in PRIV and all other process gets busy.

You can detect this by checking the process queue in SM51 / goto / server name / Information / queue info

=> according to the low level of process queue there is no major impact.

But it can be good to investigate & identify the prog / transaction that cause this behavior.

Check if user selection are appropriate (not too wide) and in case of custom program  have a look at the ABAP.

What is your OS ?

Regards

[jsanghvi]

Hello,

OS : Linux x86_64

I see following under info queue

Process Type	Requests waiting	Max. No. of Requests Wait.	Maximum number of requests	Requests written	Number of requests read
NOWP	0	21	2000	2220880	2220880
DIA	0	29	2000	1022368	1022368
UPD	0	3	2000	306	306
ENQ	0	1	2000	1	1
BTC	0	3	2000	121633	121633
SPO	0	1	2000	56826	56826
UP2	0	1	2000	151	151

Do I need to increase the em/initial_size_mb to 16 Gb

And DO I need to decrease the some DIA and BGD work processes to free some memory?

Regards,

Jigar

[ACE-SAP]

Hi

Decreasing the number of process should not really help (if they are not used they do not consume a lot of memory and if they are used removing some will decrease the whole instance perf...)

Try at first to increase em/initial_size_mb to 8Gb and more important try to find which programs makes process to get into PRIV

Regards

[former_member188883]

Hi Jigar,

Please update below configuration parameters

em/initial_size_MB	8096	MB
em/blocksize_KB		4096	kB
ztta/roll_area		3000000	Byte
ztta/roll_first		1	Byte
ztta/short_area		3200000	Byte

em/global_area_MB       250 MB

Compare your parameter values with the one listed above. If possible update above recommendation in your system. Then execute sappfpar check=<path of instance profile> to adjust the shared memory segments.

Hope this helps.

Regards,

Deepak Kori