We're seeing huge performance problems on a web application and we're trying to find the bottleneck. I am not a sysadmin so there is some stuff I don't quite get. Some basic investigation shows the CPU to be idle, lots of memory to be available, no swapping, no I/O, but a high average load.
The software stack on this server looks like this:
. Solaris 10
. Java 1.6
. WebLogic 10.3.5 (8 domains)
The applications running on this server talk with an Oracle database on a different server.
This server has 32GB of RAM and 10 CPUs (I think).
Running prstat -Z gives something like this:
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
3836 ducm0101 2119M 2074M cpu348 58 0 8:41:56 0.5% java/225
24196 ducm0101 1974M 1910M sleep 59 0 4:04:33 0.4% java/209
6765 ducm0102 1580M 1513M cpu330 1 0 1:21:48 0.1% java/291
16922 ducm0102 2115M 1961M sleep 58 0 6:37:08 0.0% java/193
18048 root 3048K 2440K sleep 59 0 0:06:02 0.0% sa_comm/4
26619 ducm0101 2588M 2368M sleep 59 0 8:21:17 0.0% java/231
19904 ducm0104 1713M 1390M sleep 59 0 1:15:29 0.0% java/151
27809 ducm0102 1547M 1426M sleep 59 0 0:38:19 0.0% java/186
2409 root 15M 11M sleep 59 0 0:00:00 0.0% pkgserv/3
27204 root 58M 54M sleep 59 0 9:11:38 0.0% stat_daemon/1
27256 root 12M 8312K sleep 59 0 7:16:40 0.0% kux_vmstat/1
29367 root 297M 286M sleep 59 0 11:02:13 0.0% dsmc/2
22128 root 13M 6768K sleep 59 0 0:10:51 0.0% sendmail/1
22133 smmsp 13M 1144K sleep 59 0 0:01:22 0.0% sendmail/1
22003 root 5896K 240K sleep 59 0 0:00:01 0.0% automountd/2
22074 root 4776K 1992K sleep 59 0 0:00:19 0.0% sshd/1
22005 root 6184K 2728K sleep 59 0 0:00:31 0.0% automountd/2
27201 root 6248K 344K sleep 59 0 0:00:01 0.0% mount_stat/1
20964 root 2912K 160K sleep 59 0 0:00:01 0.0% ttymon/1
20947 root 1784K 864K sleep 59 0 0:02:22 0.0% utmpd/1
20900 root 3048K 608K sleep 59 0 0:00:03 0.0% ttymon/1
20979 root 77M 18M sleep 59 0 0:14:13 0.0% inetd/4
20849 daemon 2856K 864K sleep 59 0 0:00:03 0.0% lockd/2
17794 root 80M 1232K sleep 59 0 0:06:19 0.0% svc.startd/12
17645 root 3080K 728K sleep 59 0 0:00:12 0.0% init/1
17849 root 13M 6800K sleep 59 0 0:13:04 0.0% svc.configd/15
20213 root 84M 81M sleep 59 0 0:47:17 0.0% nscd/46
20871 root 2568K 600K sleep 59 0 0:00:04 0.0% sac/1
3683 ducm0101 1904K 1640K sleep 56 0 0:00:00 0.0% startWebLogic.s/1
23937 ducm0101 1904K 1640K sleep 59 0 0:00:00 0.0% startWebLogic.s/1
20766 daemon 5328K 1536K sleep 59 0 0:00:36 0.0% nfsmapid/3
20141 daemon 5968K 3520K sleep 59 0 0:01:14 0.0% kcfd/4
20093 ducm0101 2000K 376K sleep 59 0 0:00:01 0.0% pfksh/1
20797 daemon 3256K 240K sleep 59 0 0:00:01 0.0% statd/1
6181 root 4864K 2872K sleep 59 0 0:01:34 0.0% syslogd/17
7220 ducm0104 1268M 1101M sleep 59 0 0:36:35 0.0% java/138
27597 ducm0102 1904K 1640K sleep 59 0 0:00:00 0.0% startWebLogic.s/1
27867 root 37M 4568K sleep 59 0 0:13:56 0.0% kcawd/7
12685 ducm0101 4080K 208K sleep 59 0 0:00:01 0.0% vncconfig/1
ZONEID NPROC SWAP RSS MEMORY TIME CPU ZONE
42 135 22G 19G 59% 87:27:59 1.2% dsuniucm01
Total: 135 processes, 3167 lwps, load averages: 54.48, 62.50, 63.11
I understand that CPU is mostly idle, but the load average is high, which is quite strange to me. Memory doesn't seem to be a problem.
Running vmstat 15 gives something like this:
kthr memory page disk faults cpu
r b w swap free re mf pi po fr de sr s0 s1 s4 sd in sy cs us sy id
0 0 0 32531400 105702272 317 1052 126 0 0 0 0 13 13 -0 8 9602 107680 10964 1 1 98
0 0 0 15053368 95930224 411 2323 0 0 0 0 0 0 0 0 0 23207 47679 29958 3 2 95
0 0 0 14498568 95801960 3072 3583 0 2 2 0 0 3 3 0 21 22648 66367 28587 4 4 92
0 0 0 14343008 95656752 3080 2857 0 0 0 0 0 3 3 0 18 22338 44374 29085 3 4 94
0 0 0 14646016 95485472 1726 3306 0 0 0 0 0 0 0 0 0 24702 47499 33034 3 3 94
I understand that the CPU is mostly idle, no processes are waiting in the queue to be executed, little swapping is happening.
Running iostat 15 gives this:
tty sd0 sd1 sd4 ssd0 cpu
tin tout kps tps serv kps tps serv kps tps serv kps tps serv us sy wt id
0 676 324 13 8 322 13 8 0 0 0 159 8 0 1 1 0 98
1 1385 0 0 0 0 0 0 0 0 0 0 0 0 3 4 0 94
0 584 89 6 24 89 6 25 0 0 0 332 19 0 2 1 0 97
0 296 0 0 0 0 0 0 0 0 0 0 0 0 2 2 0 97
1 1290 43 5 24 43 5 22 0 0 0 297 20 1 3 3 0 94
Running netstat -i 15 gives the following:
input aggr26 output input (Total) output
packets errs packets errs colls packets errs packets errs colls
1500233798 0 1489316495 0 0 3608008314 0 3586173708 0 0
10646 0 10234 0 0 26206 0 25382 0 0
11227 0 10670 0 0 28562 0 27448 0 0
10353 0 9998 0 0 29117 0 28418 0 0
11443 0 12003 0 0 30385 0 31494 0 0
Running swap -l gives this:
swapfile dev swaplo blocks free
/dev/swap 4294967295,4294967295 16 4194288 1000656
Running swap -s gives this:
total: 102575560k bytes allocated + 11141528k reserved = 113717088k used, 6692864k available
What am I missing?
Thanks a lot for your help!
Best Answer
With some further investigation, it appears that the performance problem is mostly due to a high number of network calls between two systems (Oracle SSXA and UCM). The calls are quick but plenty and serialized, hence the low CPU usage (mostly waiting for I/O), the high load average (many calls waiting to be processed) and especially the long response times (by accumulation of small response times).
Thanks for your insight on this problem!