IDS Forum

high buffer wait ratio

Posted By: miyaki
Date: Monday, 19 April 2004, at 3:08 a.m.

Hi all,

My users are complaining the database slowness. I
noticed that the buffer wait ratio at my database is
quite high, around 58% and LRU contention is at 3.29%.
How can i improve the database performance?

Here's some info that might help for analysis.

OS = Solaris 2.7
IDS 7.31.UC2

NETTYPE tlitcp,1,100,NET
NETTYPE ipcshm,3,100,CPU
DEADLOCK_TIMEOUT 10
RESIDENT 0
MULTIPROCESSOR 1
NUMCPUVPS 3
SINGLE_CPU_VP 0
NOAGE 1
AFF_SPROC 1
AFF_NPROCS 3
LOCKS 2000000
BUFFERS 30000
NUMAIOVPS 2
PHYSBUFF 32
LOGBUFF 32
LOGSMAX 350
CLEANERS 32
SHMBASE 0x50000000
SHMVIRTSIZE 147456
SHMADD 14336
SHMTOTAL 0
CKPTINTVL 600
LRUS 32
LRU_MAX_DIRTY 2
LRU_MIN_DIRTY 1
LTXHWM 40
LTXEHWM 50
TXTIMEOUT 0x12c
STACKSIZE 64
RA_PAGES 64
RA_THRESHOLD 32
OPTCOMPIND 0

Profile
dskreads pagreads bufreads Êched dskwrits pagwrits
bufwrits Êched
8240066 5913261 1107258877 99.26 778190 1102988
3511005 77.84

isamtot open start read write rewrite
delete commit rollbk
259438585 14166422 24177572 150718210 296141 308870
46026 144071 58

gp_read gp_write gp_rewrt gp_del gp_alloc gp_free
gp_curs
0 0 0 0 0 0
0

ovlock ovuserthread ovbuff usercpu syscpu
numckpts flushes
0 0 0 20309.42 1745.31 27
54

bufwaits lokwaits lockreqs deadlks dltouts ckpwaits
compress seqscans
5030714 1547 159474098 0 0 1052
44578 506896

ixda-RA idx-RA da-RA RA-pgsused lchwaits
3983298 60547 1529713 5441731 3104843

32 buffer LRU queue pairs priority
levels
# f/m pair total % of length LOW MED_LOW
MED_HIGH HIGH
0 f 933 98.3% 917 0 30
813 74
1 m 1.7% 16 0 16
0 0
2 f 923 98.5% 909 0 29
810 70
3 m 1.5% 14 0 14
0 0
4 f 931 98.7% 919 0 31
831 57
5 m 1.3% 12 0 12
0 0
6 f 930 98.4% 915 0 26
818 71
7 m 1.6% 15 0 15
0 0
8 f 923 98.9% 913 0 26
828 59
9 m 1.1% 10 0 8
2 0
10 f 922 98.6% 909 0 20
825 64
11 m 1.4% 13 0 12
1 0
12 f 934 98.6% 921 0 34
820 67
13 m 1.4% 13 0 13
0 0
14 f 924 98.6% 911 0 22
807 82
15 m 1.4% 13 0 12
1 0
16 f 929 98.5% 915 0 27
821 67
17 m 1.5% 14 0 13
1 0
18 f 928 98.8% 917 0 19
831 67
19 m 1.2% 11 0 11
0 0
20 f 925 98.2% 908 0 21
812 75
21 m 1.8% 17 0 16
1 0
22 f 925 98.5% 911 0 23
826 62
23 m 1.5% 14 0 13
1 0
24 f 935 98.5% 921 0 27
832 62
25 m 1.5% 14 0 12
2 0
26 f 923 97.9% 904 0 15
827 62
27 m 2.1% 19 0 18
1 0
28 f 928 98.2% 911 0 22
821 68
29 m 1.8% 17 0 17
0 0
30 f 922 97.9% 903 0 15
821 67
31 m 2.1% 19 0 18
1 0
32 f 902 97.5% 879 0 12
802 65
33 m 2.5% 23 0 22
1 0
34 f 947 98.1% 929 0 35
821 73
35 m 1.9% 18 0 18
0 0
36 f 926 98.6% 913 0 26
812 75
37 m 1.4% 13 0 12
1 0
38 f 931 98.4% 916 0 25
809 82
39 m 1.6% 15 0 13
2 0
40 F 917 98.8% 906 0 16
818 72
41 m 1.2% 11 0 11
0 0
42 f 924 98.4% 909 0 23
814 72
43 m 1.6% 15 0 14
1 0
44 f 932 98.2% 915 0 23
823 69
45 m 1.8% 17 0 17
0 0
46 f 919 98.3% 903 0 13
822 68
47 m 1.7% 16 2 13
1 0
48 f 920 98.5% 906 0 14
832 60
49 m 1.5% 14 0 14
0 0
50 f 925 97.8% 905 0 21
801 83
51 m 2.2% 20 0 20
0 0
52 f 924 98.7% 912 0 20
843 49
53 m 1.3% 12 0 12
0 0
54 f 922 98.7% 910 0 26
820 64
55 m 1.3% 12 0 12
0 0
56 f 927 98.2% 910 0 23
815 72
57 m 1.8% 17 0 16
1 0
58 f 927 98.3% 911 0 18
823 70
59 m 1.7% 16 0 15
1 0
60 f 919 98.9% 909 0 19
835 55
61 m 1.1% 10 0 10
0 0
62 f 931 98.8% 920 0 34
813 73
63 m 1.2% 11 0 11
0 0
471 dirty, 29628 queued, 30000 total, 32768 hash
buckets, 2048 buffer size
start clean at 2% (of pair total) dirty, or 18 buffs
dirty, stop at 1%
0 priority downgrades, 0 priority upgrades




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Messages In This Thread

• high buffer wait ratio
  miyaki -- Monday, 19 April 2004, at 3:08 a.m.
  • Re: high buffer wait ratio
    Martin Fuerderer -- Monday, 19 April 2004, at 5:15 a.m.
  • Re: high buffer wait ratio
    ART KAGEL, BLOOMBERG/ 499 PARK -- Monday, 19 April 2004, at 9:10 a.m.

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