Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations gkittelson on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

AIX Oracle slowness issue

Status
Not open for further replies.

dawaves

MIS
Jul 15, 2002
13
US
Hello,

I'm coming across this odd issue where every so often (really sporadic), my p5 510 running 1.9Ghz 1-way with 5GB of RAM on AIX 5.3 ML04 will run in a super slow state. It always happens on a weekday, always between 9:15AM - 10:00AM, and the only fix seems to be a reboot. I try to run commands during this state but the response is too long for me to wait since this is a Production machine. I run my commands from the console too, but still takes too long. I can ping the server, but my oracle apps can't connect.

I can't really tell if the system is 'Thrashing', but isn't that a tell-tale sign of a system that takes forever to respond?

The SGA size is 1.8GB.

I am using CIO mounted filesystems for Oracle. Since I'm using CIO, isn't tweaking the vmo values moot?

I did do a test yesterday w/ our DBA and had him run several SQL statements that ran reads/writes to our Oracle Database and there were high periods of 'po' values in vmstat when ran all at the same time.

In the /etc/security/limits file, here is what I have:

oracle:
fsize = -1
data = -1
rss = -1
stack = -1
cpu = -1
nofiles = -1

This pretty much allows oracle user unlimited usage of resources including memory. I was told by Oracle to do this. What do you guys think of putting a hard limit on rss_hard instead so oracle can't usurp all of the memory.


Here are some statistics of the system during window I've specified above.

# vmstat -I 2

kthr memory page faults cpu
-------- ----------- ------------------------ ------------ -----------
r b p avm fre fi fo pi po fr sr in sy cs us sy id wa
1 0 0 1269791 2305 271 25 150 0 183 5736 281 2081 616 22 3 37 39
0 1 0 1269826 3601 250 73 174 60 1128 32260 400 4178 920 17 5 37 41
2 1 0 1264021 8311 410 6 137 0 0 0 285 2690 729 17 2 39 41
0 1 0 1262058 9109 410 32 154 0 0 0 341 2006 737 14 3 41 43
1 1 0 1265977 4259 327 4 138 0 0 0 270 2932 594 22 3 37 38
0 1 0 1270081 2322 301 8 162 27 1546 34085 577 4924 1136 17 5 38 40
1 1 0 1270085 3823 310 22 164 44 1260 18072 442 3102 957 14 4 40 42
1 1 0 1264271 8398 485 26 145 0 0 0 285 1333 648 9 2 43 45
1 1 0 1262308 9653 206 7 148 0 0 0 256 1993 565 23 2 37 38
1 0 0 1266088 5085 271 30 104 0 0 0 259 2841 563 39 3 28 31
2 0 0 1264067 8189 561 11 78 31 1187 23368 352 6659 754 58 6 17 19
5 0 0 1272173 3331 801 9 72 574 2266 32042 455 9520 720 42 7 24 27
1 1 0 1266288 7477 807 6 62 0 0 0 280 2056 576 35 2 30 32
1 1 0 1266024 6482 589 5 37 0 0 0 582 6605 1196 51 4 22 23
2 0 0 1270404 2423 562 11 45 137 769 5268 648 10259 1271 52 7 20 21
0 1 0 1274318 2226 682 6 48 1543 2633 3702 488 4457 585 39 7 27 28
0 1 0 1269710 6955 60 17 40 129 129 151 546 9169 1115 28 6 54 12


# svmon -G
size inuse free pin virtual
memory 1261568 1245228 16340 132874 1188198
pg space 3637248 254426
work pers clnt
pin 132874 0 0
in use 1024221 0 221007
PageSize PoolSize inuse pgsp pin virtual
s 4 KB - 1194956 238202 100378 1122966
m 64 KB - 3142 1014 2031 4077
#
# lsps -a
Page Space Physical Volume Volume Group Size %Used Active Auto Type
paging00 hdisk3 oraclevg 8192MB 8 yes yes lv
hd6 hdisk1 rootvg 6016MB 7 yes yes lv
#

# vmo –a
cpu_scale_memp = 8
data_stagger_interval = 161
defps = 1
force_relalias_lite = 0
framesets = 2
htabscale = n/a
kernel_heap_psize = 4096
large_page_heap_size = 0
lgpg_regions = 0
lgpg_size = 0
low_ps_handling = 1
lru_file_repage = 0
lru_poll_interval = 10
lrubucket = 131072
maxclient% = 80
maxfree = 1088
maxperm = 968863
maxperm% = 80
maxpin = 1018607
maxpin% = 80
mbuf_heap_psize = 65536
memory_affinity = 1
memory_frames = 1261568
memplace_data = 2
memplace_mapped_file = 2
memplace_shm_anonymous = 2
memplace_shm_named = 2
memplace_stack = 2
memplace_text = 2
memplace_unmapped_file = 2
mempools = 1
minfree = 960
minperm = 242215
minperm% = 20
nokilluid = 0
npskill = 36608
npsrpgmax = 292864
npsrpgmin = 219648
npsscrubmax = 292864
npsscrubmin = 219648
npswarn = 146432
num_spec_dataseg = 0
numpsblks = 4685824
page_steal_method = 0
pagecoloring = n/a
pinnable_frames = 1144691
npsrpgmin = 219648
npsscrubmax = 292864
npsscrubmin = 219648
npswarn = 146432
num_spec_dataseg = 0
numpsblks = 4685824
page_steal_method = 0
pagecoloring = n/a
pinnable_frames = 1144691
pta_balance_threshold = n/a
relalias_percentage = 0
rpgclean = 0
rpgcontrol = 2
scrub = 0
scrubclean = 0
soft_min_lgpgs_vmpool = 0
spec_dataseg_int = 512
strict_maxclient = 1
strict_maxperm = 0
v_pinshm = 0
vm_modlist_threshold = -1
vmm_fork_policy = 1
vmm_mpsize_support = 1


I just think we have too little physical memory for our workload, but I would love to hear what you guys think and how your AIX/Oracle environments are tuned.

Thanks!
 
Hi

Consider lowering minperm% and maxperm%

e.g.

minperm%=10
maxperm%=40 (you will need to lower maxclient%=40 too)

and see what difference that makes.

HTH

Kind Regards,
Matthew Bourne
"Find a job you love and never do a day's work in your life.
 
Yes, lowering minperm and maxperm will resolve this issue. Are you using AIOs?


 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top