High swaps in ST02
Hi All,
Does anyone know what should I do if I found that my system has high buffer swaps. The hit ratio is good enough(99%).
Thanks & Regards,
Casper
Hi casper,
a high Hit ratio is not ALWAYS a good thing. Is it possible that a very large table is buffered constantly in the buffer, which is accessed frequently, as a result of which, you get a high hit ratio, but there is no space left for other tables.
Please check if the ratio of Buffer Gets : User Calls if it is greater than 15..
Ifi t is, then you have some expensive select statements running and you need to tune those.
Hope this helps.
Regards
Shantanu
Similar Messages
-
Swapping in ST02 in Initial Record Buffer rsdb/ntab/irbdsize
Hello All,
I've been trying to do some tuning in ST02 and was hoping someone might be able to explain why I am getting such a low hit rate on the Initial Records Buffer, and the high level of swapping, when there appears to be plenty free space and plenty free entries.
Here are the stats I see.
Efficiency
HITRATIO % 42
HITS 9,645
REQUESTS 22,790
DB access quality % 42
DB access 13,136
DB access saved 9,645
Reorgs 0
Size
Allocated KB 8,750
Available KB 7,500
Used KB 1,053
Free KB 6,447
Directory entries
Available 10,000
Used 3,801
Free 6,199
Swaps
Objects swapped 9,335
Frames swapped 0
Resets Total 0
Any clues would be much appreciated.
Thanks
SteveI have the same issue and my parameter settings are currently:
rsdb/ntab/irbdsize - 41500
rsdb/ntab/entrycount 45000
Are there any other suggestions? See below for swap information.
Efficiency HITRATIO % 43
HITS 10,243
REQUESTS 23,731
DB access quality % 43
DB access 13,488
DB access saved 10,243
Reorgs 0
Size Allocated KB 42,906
Available KB 41,500
Used KB 4,717
Free KB 36,783
Directory entries Available 11,250
Used 9,759
Free 1,491
Swaps Objects swapped 3,728
Frames swapped 0
Resets Total 0 -
Hi Gurus,
I have been seeing lot of swaps occuring in ST02,in one our production servers.
I could see the swaps occuring on CUA buffers in huge volumes
Can any body give me any clue on how to go about it,interms of analysing the swaps and fixing the same
Your help would highly be appriciated
Thanks in advance
Rgds-
Venuhello
you will find some help here : [Online help about buffers|http://help.sap.com/erp2005_ehp_04/helpdata/EN/c4/3a6e98505211d189550000e829fbbd/frameset.htm]
"When a buffer has insufficient freespace or free directories, it has to swap objects out of the buffer in order to load a new object. The column Swap shows how many objects have been swapped out since system startup."
This means that you have to increase the size of the buffer to avoid swapping.
To find the relevant parameter (in RZ10) for a specific buffer => transaction ST02, double click on the buffer and then click on the button "Current parameters". Here is/are the parameter(s) to increase (be careful of some parameters ... your system can crash or not restart !)
After saving & activating the profile in RZ10, perform at os level the command (under <sid>adm) : sappfpar check to fix the memory problems.
Hope this will help you -
Hi
In my Development System when i check Tune Summary (ST02) ,i could see Swap rate is high for some prarameters viz
Program buffer PXA
abap/buffersize 400000 kB Size of program buffer
abap/pxa shared Program buffer mode
Screen buffer PRES
zcsa/presentation_buffer_area 4400000 Byte Size of screen buffer
sap/bufdir_entries 2000 Max. number of buffered screens
Generic key table buffer TABL
zcsa/table_buffer_area 30000000 Byte Size of generic key table buffer
zcsa/db_max_buftab 5000 Max. number of buffered objects
Export/import buffer EIBUF
rsdb/obj/buffersize 4096 kB Size of export/import buffer
rsdb/obj/max_objects 2000 Max. number of objects in the buffer
rsdb/obj/large_object_size 8192 Bytes Estimation for the size of the largest object
rsdb/obj/mutex_n 0 Number of mutexes in Export/Import buffer
Swap rate for Export/import buffer is almost 120 swaps per day.
Moreover 2 instance are running on these server having 4gb RAM Capacity.
plz tell me to what extent i have to increase the size of these parameters so that swap rate comes down.
regards
suresh
Message was edited by:
ganesh reddy kanthalaHi
Thanks for ur immediate response.
I have installed ECC 6.0 version R/3 system .25 users are working in my Development system.
kindly let me know what docs i have to follow inorder to increase the buffer parameters.
Regards
ganesh -
High swap file utilization - 11g on windows 2003 x64
Hi,
I'm running database 11.1.0.6 patch set 10 on
Windows Server 2003 x64 standard
HP DL380 dual quad core + 8GB RAM
2 x 72GB 15K SAS mirror for OS
6 x 72GB 15k SAS RAID-5 for data + logs (i know ideally logs need to move to a RAID-1 set etc)
dedicated mode
database is about 10GB (main set of tables about 1GB)
SGA + PGA 4GB (auto memory management)
server has been set to network application mode such that less mem is allocated to the system cache etc.
Large Page support has been enabled (not confirmed if this is working, any ideas how to?)
Looking at the page faults and page out perf mon stats it looks too high/ too much given the arrangement above. The majority of the page faults are coming from the Oracle.exe process. But I cannot explain why specially if Large Page is setup then the SGA etc should be locked in to RAM as I understand.
side note I was seeing similar behaviour on the older 10.2.0.1 DB that had same mem config for the same set of data.
Any ideas people?
ThanksJA,
On the server, open Task Manager and then select the Processes tab. Make certain that it is configured to show the Page Faults column and click on the entry for the Oracle instance so that it is highlighted. Then, open a command prompt and start SQL*Plus with the /NOLOG command line parameter. Make note of the current value of Page Faults and then connect to the database instance using SQL*Plus using the SYS user account (or some other account). You will probably find that the Page Faults value jumped by about 302 as a result of the login, and the value just might jump again when you disconnect from the database. Keep in mind that each session connecting to an Oracle instance running on Windows will require at least 1MB of memory immediately on connection as an additional thread is created (assuming shared server is not used). If each memory page were 4KB in size (as is the standard in Windows), there would likely be at least 256 (1MB / 4KB) page faults for each login, and possibly the same amount per disconnect. With this in mind, I am not so certain that 500 page faults per second is a high value for a Oracle process running on Windows if users/applications are constantly connecting and disconnecting from the Oracle database instance.
To determine if there is a performance problem caused by memory utilization, what you may want to do is take a look at the PF Usage value on the Performance tab of Task Manager. This is NOT the page file usage, regardless of the warnings that appear in Enterprise Manager - this is total memory allocation including RAM and swap file usage. There is an interesting thread where I discovered the actual meaning of PF Usage here:
http://groups.google.com/group/comp.databases.oracle.server/browse_thread/thread/b62c4d761cace2a6
If the PF Usage is considerably less than the amount of the RAM in the server (8GB RAM -> PF near 7GB is OK), you will likely be OK, as long as you do not attempt to move multi-gigabyte files around - doing so could cause short term memory starvation issues for Oracle. You might want to verify that the File and Printer Sharing option of the network card is set to "Maximize throughput for network applications" so that Windows will limit the memory used for file caching.
Charles Hooper
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc. -
Dear Experts,
In Transaction ST02 there are heavy swaps in the following buffers:
Field description
Initial records
Program
CUA
Screen
Tables
Generic key
Single record
Export/import
How to reduce them; If parameters has to be changed Pl let me know the parameters to be changed and also sequence to be followed.
It would really be helpful if you could let me know how to calculate the parameter values, and sequence to be followed as ease.
Details:
OS: HP-UX 11.23
ECC 5.0
Oracle Release 9.2.0.6.0
Physical mem avail Kb 16,764,976
Regards
InjamuriHi,
Please click [buffers|http://help.sap.com/erp2005_ehp_04/helpdata/EN/c4/3a6e98505211d189550000e829fbbd/frameset.htm] for information.
For Table Buffer or TABL
zcsa/table_buffer_area u2013 for size of table buffer data area.
zcsa/db_max_buftab u2013 for directory entries u2013 one for every resident table
For Single key table Buffer or TABLEP.
rtbb/max_tables u2013 Directory Entries u2013 One for each table.
rtbb/buffer_length u2013 Size of data area
Program buffer
abap/buffersize u2013 Only parameter. No of directory entries are calculated automatically.
For Screen Buffer or PRES.
zcsa/bufdir_entries u2013 Directory size u2013 One per screen.
zcsa/presentation_buffer_area u2013 Total screen buffer size in KB.
CUA buffers
rsdb/cua/buffersize u2013 total Buffer in KB and no of directories are caluated by dividing the same with 2K.
Role and paging buffer.
rdisp/ROLL_SHM u2013 For role buffer
rdisp/PG_SHM u2013 For paging buffer
Calendar Buffer
zcsa/calendar_area
With Regards,
Krishna. -
Dear All,
Any specific command or steps to find which process consuming lot of swap space and there is any specific step to reduce the usage without kill the actual process.
Regards,
Sivaprstat -s size
..gives you a list of processes sorted on their memory consumption. The swap and memory are tightly connected in a virtual-memory structure, which means that i don't think you can tell exactly how much of a process which is swapped out and how much which is in RAM.
The RSS column of the prstat output shows how much which is residential, that part is for sure in the RAM, the rest may or may not be swapped out.
You can not reduce the amount of swap used by a process (i'ld guess that you probably could force it into the RAM, but thats probably not what you want), but if swap size is an issue, you can add space to the swap easily by using swap -a on a file or device.
.7/M. -
Hi all,
We just increased the program buffer from 850 MB to 950 MB 3 weeks back and then to 1050 MB a week back.The system looks normal for a few days and then again i can see the swpas increaing.We already have 16 GB of memory on a 64bit Win NT platform.The DB is db2 v 8.1.5......
So should i again increae it. also i read somewhere that increasing too much program buffer area willl lead to buffer fragmentation .
I am not sure . please suggest if it is ok to increase.
Also the Nametab ,Table definition, Short NTAB,Field definition, Initial records buffers are showing a lot of swaps ..
I looked at the relevant parameters:
rsdb/ntab/entrycount = 70000
rsdb/ntab/ftabsize = 62500 KB
rsdb/ntab/sntabsize = 2500 KB
rsdb/ntab/irbdsize = 30 000 KB
Which values should i change...please suggest.....Hi Kalyan and Juan,
thanks.. for replying...
The program buffer is showing about 18000 swaps...
also the
Field definition buffer shows 151,000 buffer swaps,
Short NTAB = 19,418 buffer swaps and
initial records buffer = 54,158 buffer swaps.
We just increased the program buffer from 850 MB to 950 MB 3 weeks back and then to 1050 MB a week back.The system looks normal for a few days and then again i can see the swpas increaing.We already have 16 GB of memory on a 64bit Win NT platform.The DB is db2 v 8.1.5......
Should there be something that has to be changed in the DB2 side, or should i again increae it. also i read somewhere that increasing too much program buffer area willl lead to buffer fragmentation .
I am not sure . please suggest if and to what extent i can increase....
Also the Nametab ,Table definition, Short NTAB,Field definition, Initial records buffers are showing a lot of swaps ..
I looked at the relevant parameters:
rsdb/ntab/entrycount = 70000
rsdb/ntab/ftabsize = 62500 KB
rsdb/ntab/sntabsize = 2500 KB
rsdb/ntab/irbdsize = 30 000 KB -
Swaps values showing in RED -TCODE ST02
Hi All,
When I checked the ST02 transaction value of "SWAPS" for program buffer,CUA buffer,screen buffer, Tables generic key buffer and export/import buffer are showing in "RED" colour.
(%) (kb) %
Buffer Hitratio Allocated Free Space swaps
Program 99.88 900000 0.36 19541
CUA 99.9 10,000 1.27 37960
export/import 94.33 40,000 29.10 750,676
Swaps value are showing in RED mark....Is there somthing fishy? What can be done to overcome this issue?
Thanks in advance
Regards,
Prashant.Dear Prashant,
SWAP is the amount of page space available at OS level. In case of windows it should not be more than 4 times the ram and in case of UNIX 3 times the ram. If swap or paging is configured high is the paging rate and low is the performance. If there is no more free directory entries are available in the buffer for new objects, old objects are removed and the space is occupied by new objects thus a swapping takes place i.e some buffer content is removed from the buffer and replaced by new buffer contents. High swap is normally a symptom of memory bottleneck.
Red indicates swaps are to be avoided and indicate that there might be a bottleneck.
What can be done to overcome this issue?
You need to increase the parameter then.
Double-click on the red value, click on "current parameters" and increase that parameter in the instance profile using RZ10. If the parameters are not yet in the profile, add them.
After changing the instance profile you need to restart the instance.
Regards,
Ashutosh -
Hi all,
When i checked the swaps in st02 it is showing as red.What to do plz.Should i change the parameters.
Buffer Hitratio Allocated Free space Dir. size Free directory Swaps Database
[%] [kB] [kB] [%] Entries Entries [%] accesses
Nametab (NTAB)
Table definition 96.10 7,151 0 0.00 30,000 0 0.00 159,968 385,089
Field description 96.55 32,344 5,702 19.01 30,000 21,404 71.35 254,965 263,737
Short NTAB 99.74 3,438 2,137 85.48 7,500 5,803 77.37 0 1,697
Initial records 96.18 5,438 177 3.93 7,500 654 8.72 96,328 103,175
Program 93.68 500,000 1,322 0.28 125,000 111,378 89.10 161,705 626,010
CUA 99.94 8,000 4,836 70.38 4,000 3,475 86.88 0 530
Screen 99.86 25,391 18,314 72.89 4,500 4,016 89.24 0 516
Calendar 100.00 488 394 82.08 200 95 47.50 0 105
OTR 100.00 4,096 3,531 100.00 2,000 2,000 100.00 0 0
Tables
Generic key 99.99 99,023 9,072 9.44 13,000 998 7.68 12 59,612
Single record 97.10 100,000 75,927 76.12 1,000 876 87.60 0 171,530
Export/import 66.42 20,000 11,764 81.85 20,000 18,587 92.94 0 0
Exp./Imp. SHM 16.95 4,096 3,490 98.84 2,000 1,999 99.95 0 0Hi Ambarish,
These are the values which u can take as reference
rsdb/ntab/entrycount 30000
rsdb/ntab/irbdsize 4000
rsdb/ntab/sntabsize 2500
rsdb/cua/buffersize 5000
sap/bufdir_entries 10000
zcsa/table_buffer_area 50000000
zcsa/db_max_buftab 10000
rtbb/buffer_length 30000
rtbb/max_tables 500
Release 4.0/4.5:
rsdb/obj/buffersize 4096 (kB)
rsdb/obj/max_objects 5000 (buffer entries)
rsdb/obj/large_object_size 8192 (Byte)
As of Release 4.6:
rsdb/obj/buffersize 20000 (kB)
rsdb/obj/max_objects 20000
rsdb/obj/large_object_size 8192 (Byte)
extend the buffers to 30 -40% this may help you
Regards'
Zia -
Dear Friends,
I am facing problem with SWAPS in ST02.I know the soloution like restarting the sytem/increasing the parametrers.Can any body help me in this issue with any other solution.i already restarted the system And one more thing is there any limit for swaps for each buffer.i am giving my PRD server swaps here.
Nametab (NTAB) swaps
Table definitio 1,342,725
Field definitio 910,742
Short NTAB
Initial records 970,789
program 2,527,221
CUA 3,473,889
Screen 119,352
Calendar
OTR
Tables
Generic Key 4,696
Single record 1,085
Export/import 11,735,724
Exp./ Imp. SHM
Thanks&Regards,
chaitanya.Hi Chaitanya,
The only way to control the amount of swaps the system produce is to fine tune the system parameters, a system restart only clear the existing ones but does not prevent swaps for happening...
is there any limit for swaps for each buffer
Nope, it will swap as many times as it needs to...
Can any body help me in this issue with any other solution?
As mention above the only solution is to tune your parameters and keep your kernel updated, small amount of swaps in ok, but excesive swaping it can go in detriment of your system performance.
I can tell you that 2,527,221 swaps in your program buffer simply means that its probably too small and so on... you'll have to spend time looking into it.
This is a well documented issue... search, research, read, test...
Regards
Juan -
Hi All,
Upon fresh installation of ECC 6.0 EPH7 and then I did a client copy, but upon checking ST02, it seems most of my buffers are low not close to 100 at all (Screenshot below).
I tried to play around with
rsdb/ntab/irbdsize
rsdb/ntab/entrycount
to tweak my initial records but still very low and does not seems to improve,
any steps where I should start beginning to troubleshot?
Thank you,
Regards,
UraHello
HitRatio are not significant after a system restart.
Here you've got low ratio but few DB access, buffer HitRatio should improve with user activity.
1918603 - High swaps in transaction ST02
It is not possible to suggest a precise value for the buffer sizes. The sizes depend on the update
level, amount of data in the system, the applications used, etc. In general, the buffer must always be set
as large as necessary to avoid swaps.
Regards -
Hello All - Happy Spring
I was going through st02 and noticed that I am having high swaps on the CRM2007 system (Oracle 10g/Aix), particularly in the following SAP buffers:
Initial records rsdb/ntab/irbdsize 6000
program abap/buffersize 300000
CUA rsdb/cua/buffersize 3000 kB
Screen zcsa/presentation_buffer_area 4400000 Byte
Generic Key zcsa/table_buffer_area 30000000
Single record rtbb/buffer_length 10000 kB
Export/import rsdb/obj/buffersize 4096 KB
PS.
when I run a check on the instance profile on the
I get a red error
E:ztta/parameter_area is smaller than default 32000 (actual is 8000)
If I increase the ztta/parameter_area would this improve the swaps issue or cause some underlying issues?
thank you for your input and suggestions.
Edited by: thanu on Mar 27, 2008 12:58 AMztta/parameter_area: Buffer Size for SPA/GPA Parameters
Size of the shared memory buffer for SPA/GPA parameters
Extract from SAP Note 34533 - Error SET_PARAMETER_MEMORY_OVERFLOW
The memory area PARAMETER_MEMORY (or also the 'SPA/GPA area') is created once for each user when they log on and is used collectively by all sessions that arise from this logon. Each piece of information that is stored there can be read by all other sessions.
An important restriction: there is no synchronization mechanism between the sessions. This means that you cannot predict EXACTLY when a piece of information that has just been stored by a sesson can be read in another session. Therefore, this area must NOT be misused for data exchange. There are other means of doing this that are better suited to the purpose. If the error mentioned above occurs, it may be that an application is responding as described above by carrying out intensive data transfer using the SPA/GPA area.
Solution
If the error SET_PARAMETER_MEMORY_OVERFLOW occurs, the first approach to solving the problem should be to increase (for example double) the SPA/GPA area. To do this, increase the parameter 'ztta/parameter_area'. The new value of the parameter is only valid once you restart the system.
It is difficult to determine the minimum size of the SPA/GPA area. It depends on the variety of the applications to be run.
You can go ahead and set ztta/parameter_area to its default size
Cheers
Shaji -
Ultra high memory usage when deleting a slide show
Hallo,
I have a DVD project with several menus and slideshows and a huge flowchart. I wanted to delete one of the slide shows. What happened then was that the memory usage rised up to over 2 GB. Not the usage of the exe shown in the windows task manager under "processes", but the swap file usage.
The first time I waited for like 5 minutes, and then Encore closed itself. Without any error message.
The next time I waited as long again, but then the swap file usage went down slowly again. After that Encore refreshed its window. The flow chart was what you could best describe as "broken". Encore then stated some abnormal condition and offered me to save the file, and recommended to save it under a different file name. I clicked on "ok", but instead of a file save dialog a C++ runtime error box appeared. I click "ok" for that, then the "you should save but under a different name" box appeared again. I clicked on "ok" again, the C++ error reappeared, and after clicking on "ok" there Encore closed itself.
I made a screenshot on which you can see the high swap file memory usage and the broken flowchart. You can download the screenshot under
http://www.digitale-bibliothek.de/Downloads/ScreenEncoreDVD.jpg
I will now try to first delete all references to the slideshow in the flow chart. But as I cannot delete an asset that is still used in a slideshow or a timeline, Encore DVD should also prevent me from deleting objects that are used in the flowchart, if it is such a problem for Encore to delete the object then.
Regards,
Christian KirchhoffI'm a little confused as to where you tried to delete the slideshow from.
Was it from the actual Project Browser, where all the assets are listed?
Can you try deleting the surplus slideshow from there, and let us know what happens please? -
HELP- Over 1 Gigabyte of "Swap Used" in Activity Monitor RAM!
Hello,
I have a late 2013 Retina Macbook Pro running Yosemite, with 8 Gigabytes of RAM. I noticed that on the Activity Monitor it shows that I have over 1 Gig of "swap used"! In the screenshot it says 974 megabytes, which is still bad. I've heard that it's okay for your memory usage to be high as long as the memory pressure graphic is green, but I've also heard that swap shouldn't be used, especially not 1 Gig of Swap.
I'm not running any high intensity programs, only Safari, Spotify, iMessage, Mail, iTunes, Chrome, and things of that sort. Why would it be so high?
High swap used is a bad thing, because it uses the SSD and shortens its lifetime. I don't even know why I would be using it, as I'm not running anything very intense.
What can I do? What should I do? Should I re-install Yosemite from scratch? Does anyone know what app could be making this happen in the background?
Kernel-Task and WindowServer are the processes that are using the most RAM that I don't know anything about. A screenshot is attached.Safari normally uses over 1 GB of ram even if I only have a few tabs open.. often I have videos loaded, though. I think I'll clear out cookies, cache of safari and then possibly re-install Yosemite.
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