[mapserver-users] MapServer webgis used too little capacity bandwidth

[Andy Colson]

Alphatran wrote:
> 
> 
> Andy Colson wrote:
>>
>> First, I think we need to find the bottleneck.
>>
>> a) If there is only one client, requesting one map, then you will not 
>> have enough data going over the line to use 200Mbps.
>>
>> b) If you have lots of clients, all requesting lots of maps, then you'll 
>> have enough data going over the line to use 200Mbps.
>>
>> Assuming b is true, then we need to see if you are cpu bound or io 
>> bound.  On you linux box watch "vmstat 5" for a while (you could even 
>> post the results if you want).
>>
>> The last column "wa" is %cpu wait time for the hard drve.  If that's 
>> high then you're io bound.
>>
>> Next column in is "id", or %cpu idle time.  If that's near zero then you 
>> are cpu bound.
>>
>> -Andy
>>
>>
> 
> Thanks Andy,
> 
> I have just tested with 2 clients. There is one map with many layers. These
> lines are result of "vmstat 5" command, please help me!
> 
> [root at gis ~]# vmstat 5
> procs -----------memory---------- ---swap-- -----io---- --system--
> -----cpu------
>  r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id
> wa st
>  0  0  31368  14268  11100 1450188    1    2   428    46   53   66  2  0 96 
> 2  0
>  0  0  31368  14396  11108 1450188    0    0     0    17  184  197  0  0 100 
> 0  0
>  0  0  31368  14388  11116 1450188    0    0     0    22  167  197  0  0 100 
> 0  0
>  0  0  31368  14468  11124 1450188    0    0     0    12  182  202  0  0 100 
> 0  0
>  0  0  31368  14468  11124 1450188    0    0     0    20  165  196  0  0 100 
> 0  0

Its a little hard to read wrapped like that, but, looks to me like cpu 
is 100% idle.  Looks like you have an extra "st" column, I'm not sure 
what that is.

With two clients, how was the response time?  You are not going to 
generate very much data, so you wont use very much network bandwidth.

200Mbps / 8 bits = 25 Meg per second, a mapfile is going to generate 
10-20k, which is what, 1% of your bandwidth.  If response time on the 
client was ok, then I'm not sure what we are trying to solve.

-Andy