[Spread-users] high cpu load

[George Schlossnagle]

Just out of curiosity, with your load so low, is your concern about the 
cpu usage more theoretical than practical?  Is it showing performance 
problems for you?

George

On Monday, September 3, 2001, at 08:40 AM, Dirk Vleugels wrote:

> Hi,
>
> On Fri, Aug 31, 2001 at 01:11:30PM -0400, George Schlossnagle wrote:
>> Yair,
>>
>> I believe if he has his ring set up as he does, it will always fail to
>> successfully muticast it's packet to it's neighbor and then have to 
>> unicast
>> it.  This would completely explain his retransmisions being the same 
>> as his
>> multicasts.
>
> Yes, doing unicast over the first and multicast over the second
> interface was the problem. Now both use the same interface, and the
> retransmissions disappeared.
>
> But, even through non-peak hours, the spread cpu-load (on the apache
> servers) is still high. I assume select() is the culprit, nearly
> all the load is system load:
>
>   2:35pm  up 15 days, 17:57,  3 users,  load average: 0.44, 0.64, 0.61
> 224 processes: 222 sleeping, 1 running, 1 zombie, 0 stopped
> CPU states: 11.1% user, 44.4% system,  0.0% nice, 44.4% idle
> Mem:  1028856K av,  994240K used,   34616K free,       0K shrd,   15972K
> buff
> Swap: 1052248K av,  299812K used,  752436K free                  689604K
> cached
>
>   PID USER     PRI  SIZE  RSS WCHAN     STAT %CPU %MEM COMMAND
> 26823 spread    14  1352 1332 do_select S    25.9  0.1 spread
>
> Would poll() do much better?
>
> Cheers,
> Dirk
>
> [cluster-sip 3&4 not active right now]
>
> Monitor> Monitor: send status query
>
> ============================
> Status at loghost-sip V 3.16. 0 (state 1, gstate 1) after 620 seconds :
> Membership  :  5  procs in 1 segments, leader is cluster1-sip
> rounds   :  626035      tok_hurry :    1195     memb change:       5
> sent pack:       6      recv pack :   22810     retrans    :       0
> u retrans:       0      s retrans :       0     b retrans  :       0
> My_aru   :   25040      Aru       :   25040     Highest seq:   25040
> Sessions :       1      Groups    :       3     Window     :      60
> Deliver M:   26506      Deliver Pk:   26549     Pers Window:      15
> Delta Mes:    1576      Delta Pack:      83     Delta sec  :     218
> ==================================
>
> Monitor>
> ============================
> Status at cluster3-sip V 3.16. 0 (state 1, gstate 1) after 403 seconds :
> Membership  :  5  procs in 1 segments, leader is cluster1-sip
> rounds   :  547884      tok_hurry :     724     memb change:       1
> sent pack:      36      recv pack :   21368     retrans    :       1
> u retrans:       1      s retrans :       0     b retrans  :       0
> My_aru   :   25040      Aru       :   25040     Highest seq:   25040
> Sessions :     116      Groups    :       3     Window     :      60
> Deliver M:   25012      Deliver Pk:   25040     Pers Window:      15
> Delta Mes:   -1494      Delta Pack:       0     Delta sec  :    -217
> ==================================
>
> Monitor>
> ============================
> Status at cluster4-sip V 3.16. 0 (state 1, gstate 1) after 509 seconds :
> Membership  :  5  procs in 1 segments, leader is cluster1-sip
> rounds   :  625773      tok_hurry :    1139     memb change:       4
> sent pack:     418      recv pack :   22396     retrans    :       0
> u retrans:       0      s retrans :       0     b retrans  :       0
> My_aru   :   25040      Aru       :   25040     Highest seq:   25040
> Sessions :     129      Groups    :       3     Window     :      60
> Deliver M:   26506      Deliver Pk:   26546     Pers Window:      15
> Delta Mes:    1494      Delta Pack:       0     Delta sec  :     106
> ==================================
>
> Monitor>
> ============================
> Status at cluster2-sip V 3.16. 0 (state 1, gstate 1) after 423 seconds :
> Membership  :  5  procs in 1 segments, leader is cluster1-sip
> rounds   :  587570      tok_hurry :     859     memb change:       2
> sent pack:   10519      recv pack :   11758     retrans    :       0
> u retrans:       0      s retrans :       0     b retrans  :       0
> My_aru   :   25040      Aru       :   25040     Highest seq:   25040
> Sessions :     185      Groups    :       3     Window     :      60
> Deliver M:   25945      Deliver Pk:   25977     Pers Window:      15
> Delta Mes:    -561      Delta Pack:       0     Delta sec  :     -86
> ==================================
>
> Monitor>
> ============================
> Status at cluster1-sip V 3.16. 0 (state 1, gstate 1) after 443 seconds :
> Membership  :  5  procs in 1 segments, leader is cluster1-sip
> rounds   :  624402      tok_hurry :    1174     memb change:       3
> sent pack:   11837      recv pack :   10963     retrans    :       0
> u retrans:       0      s retrans :       0     b retrans  :       0
> My_aru   :   25040      Aru       :   25040     Highest seq:   25040
> Sessions :     186      Groups    :       3     Window     :      60
> Deliver M:   26495      Deliver Pk:   26530     Pers Window:      15
> Delta Mes:     550      Delta Pack:       0     Delta sec  :      20
> ==================================
>
>
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