[ovirt-devel] few notes from the scale setup

Michal Skrivanek michal.skrivanek at redhat.com
Wed Jul 2 12:43:16 UTC 2014


Hi,
I'd like to share couple of observations on the scale system, just a few chaotic notes mostly for the documentation purposes:-)

4 socket, 8 core, HT -> 64 CPU
samples has been taken in +- stable conditions


1) running 100VMs; top sample with collapsed process usage (all threads sum up)

top - 15:00:48 up 5 days,  6:31,  1 user,  load average: 2.25, 1.90, 2.05
Tasks: 1989 total,   4 running, 1983 sleeping,   1 stopped,   1 zombie
Cpu(s):  4.7%us,  1.9%sy,  0.0%ni, 93.3%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  396900992k total, 80656384k used, 316244608k free,   156632k buffers
Swap: 41148408k total,        0k used, 41148408k free, 12225520k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                                                          
 9057 vdsm        0 -20 17.5g 482m   9m S 162.7  0.1 446:46.28 vdsm                                                                                                                                            
 8726 root         20   0  979m  17m 7996 R 135.6  0.0  68:56.42 libvirtd                                                                                                                                        
36937 qemu    20   0 1615m 296m 6328 S 59.2  0.1   0:19.18 qemu-kvm                                                                                                                                         
38174 root           20   0 16496 2724  880 R 32.1  0.0   0:00.54 top                                                                                                                                              
 2458 qemu      20   0 1735m 533m 6328 S 11.1  0.1   2:38.87 qemu-kvm                                                                                                                                         
10203 qemu      20   0 1736m 511m 6328 S 11.1  0.1   2:32.53 qemu-kvm                                                                                                                                         
27774 qemu      20   0 1730m 523m 6328 S 11.1  0.1   2:22.36 qemu-kvm                                                                                                                                         
25208 qemu      20   0 1733m 514m 6328 S  9.9  0.1   2:22.47 qemu-kvm                                                                                                                                         
51594 qemu      20   0 1733m 650m 6328 S  9.9  0.2   3:53.42 qemu-kvm                                                                                                                                         
… etc                                                   
[ this one's not from stable conditions, unfortunately, as can be seen by PID 36937]

----------------------------

2) running 185 VMs - all threads sum up. VDSM has 411 threads; load is much higher; also note high sys time

top - 07:10:28 up 5 days, 22:41,  1 user,  load average: 19.10, 14.28, 13.17
Tasks: 2318 total,   9 running, 2308 sleeping,   0 stopped,   1 zombie
Cpu(s): 10.8%us, 21.0%sy,  0.0%ni, 67.8%id,  0.1%wa,  0.0%hi,  0.2%si,  0.0%st
Mem:  396900992k total, 157267616k used, 239633376k free,   175700k buffers
Swap: 41148408k total,        0k used, 41148408k free, 12669856k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                                                         
 9057 vdsm       0 -20 30.1g 856m  10m S 883.4  0.2   9818:59 vdsm                                                                                                                                            
 8726 root         20   0  975m  19m 7996 R 142.4  0.0   1370:15 libvirtd                                                                                                                                        
19542 root         20   0 16700 3108 1020 R 15.1  0.0   0:18.11 top                                                                                                                                              
17614 qemu      20   0 1730m 692m 6328 S  6.5  0.2  49:05.53 qemu-kvm                                                                                                                                         
55545 qemu      20   0 1732m 708m 6328 S  6.3  0.2  48:42.01 qemu-kvm                                                                                                                                         
28542 qemu      20   0 1724m 696m 6328 S  6.2  0.2  44:44.50 qemu-kvm                                                                                                                                         
12482 qemu      20   0 1738m 822m 6328 S  6.0  0.2  51:02.71 qemu-kvm                                                                                                                                         
… etc                                                                                                                                       

break-up per thread:

top - 07:05:43 up 5 days, 22:36,  1 user,  load average: 12.50, 11.15, 12.00
Tasks: 3357 total,  35 running, 3321 sleeping,   0 stopped,   1 zombie
Cpu(s): 11.3%us, 16.0%sy,  0.0%ni, 72.5%id,  0.0%wa,  0.0%hi,  0.2%si,  0.0%st
Mem:  396900992k total, 157238240k used, 239662752k free,   175700k buffers
Swap: 41148408k total,        0k used, 41148408k free, 12669856k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                                                         
 8726 root        20   0  979m  19m 7996 R 81.6  0.0 860:14.21 libvirtd                                                                                                                                         
 9103 vdsm       0 -20 30.1g 855m  10m R 63.7  0.2 502:03.90 vdsm                                                                                                                                             
 9144 vdsm       0 -20 30.1g 855m  10m R 59.5  0.2 276:23.93 vdsm                                                                                                                                             
11150 vdsm      0 -20 30.1g 855m  10m R 59.0  0.2 399:37.86 vdsm                                                                                                                                             
 9100 vdsm       0 -20 30.1g 855m  10m R 42.7  0.2 354:41.75 vdsm                                                                                                                                             
18053 root      20   0 17708 3968 1020 R 17.2  0.0   0:17.46 top                                                                                                                                              
11845 vdsm     0 -20 30.1g 855m  10m S 15.4  0.2 114:48.08 vdsm                                                                                                                                             
 8755 root        20   0  979m  19m 7996 S 13.0  0.0  81:25.64 libvirtd                                                                                                                                         
 8753 root        20   0  979m  19m 7996 S 12.7  0.0  81:21.16 libvirtd                                                                                                                                         
64396 root       20   0  979m  19m 7996 S 12.4  0.0  80:03.68 libvirtd                                                                                                                                         
 8754 root        20   0  979m  19m 7996 R 10.0  0.0  81:26.52 libvirtd                                                                                                                                         
 8751 root        20   0  979m  19m 7996 S  9.9  0.0  81:18.83 libvirtd                                                                                                                                         
 8752 root        20   0  979m  19m 7996 R  9.7  0.0  81:28.07 libvirtd                                                                                                                                         
52567 vdsm      0 -20 30.1g 855m  10m S  4.9  0.2   9:27.75 vdsm                                                                                                                                             
30617 vdsm      0 -20 30.1g 855m  10m S  3.8  0.2  34:40.75 vdsm                                                                                                                                             
40621 vdsm      0 -20 30.1g 855m  10m S  3.8  0.2  34:12.40 vdsm                                                                                                                                             
 8952 vdsm       0 -20 30.1g 855m  10m S  3.8  0.2  24:03.79 vdsm                                                                                                                                             
29818 vdsm      0 -20 30.1g 855m  10m S  3.7  0.2   9:21.33 vdsm                                                                                                                                             
31418 vdsm      0 -20 30.1g 855m  10m S  3.7  0.2  35:09.03 vdsm                                                                                                                                             
 6858 vdsm       0 -20 30.1g 855m  10m S  3.7  0.2  34:10.79 vdsm                                                                                                                                             
18513 vdsm       0 -20 30.1g 855m  10m S  3.7  0.2  34:44.03 vdsm                                                                                                                                             
46247 vdsm       0 -20 30.1g 855m  10m S  3.7  0.2  34:16.65 vdsm                                                                                                                                             
50759 vdsm       0 -20 30.1g 855m  10m S  3.7  0.2  34:04.86 vdsm                                                                                                                                             
58612 vdsm       0 -20 30.1g 855m  10m S  3.7  0.2  31:58.11 vdsm                                                                                                                                             
25872 vdsm       0 -20 30.1g 855m  10m S  3.7  0.2  31:03.81 vdsm                                                                                                                                             
31599 vdsm       0 -20 30.1g 855m  10m S  3.7  0.2  31:10.85 vdsm                
… etc

overall network usage:
0.5-3Mbps varying, roughly corresponding to 15s

----------------------------

3) special case when vdsm was down, 185 VMs

top - 08:34:11 up 6 days, 4 min,  2 users,  load average: 5.96, 5.20, 8.71
Tasks: 2314 total,   7 running, 2306 sleeping,   0 stopped,   1 zombie
Cpu(s):  8.6%us,  4.9%sy,  0.0%ni, 86.1%id,  0.0%wa,  0.0%hi,  0.4%si,  0.0%st
Mem:  396900992k total, 157512324k used, 239388668k free,   180100k buffers
Swap: 41148408k total,        0k used, 41148408k free, 12726620k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                                                         
47776 root      20   0 17212 3592 1020 R 16.5  0.0   0:16.32 top                                                                                                                                              
35549 qemu      20   0 1806m 809m 6328 S  6.7  0.2  53:46.20 qemu-kvm                                                                                                                                         
43240 qemu      20   0 1735m 694m 6328 S  6.5  0.2  44:58.63 qemu-kvm                                                                                                                                         
51594 qemu      20   0 1733m 822m 6328 S  6.3  0.2  54:19.51 qemu-kvm                                                                                                                                         
24881 qemu      20   0 1726m 704m 6328 S  6.1  0.2  48:50.63 qemu-kvm                                                                                                                                         
58563 qemu      20   0 1728m 699m 6328 S  6.1  0.2  50:14.10 qemu-kvm                                                                                                                                         
… etc                                                                                                                                       

--------------------------

4) no disk space on /var/log (opened BZ 1115357):
disk space - libvirtd   8726    root    4w   REG  253,8 1638998016   34 /var/log/libvirtd.log (deleted)

--------------------------

5) startup of vdsm in 185 VMs environment:

on vdsm service startup the "vdsm: Running nwfilter" took ~5 minutes to finish
then VM recovery took ~20-30 minutes!


overall we need to identify the specific threads and simulate specific issues in a debug-friendly environment to tell a bit more…

Thanks,
michal








More information about the Devel mailing list