TM1 Network performance problem
Posted: Fri Jun 13, 2008 5:38 pm
We have the following problem when using TM1.
Our users accessing TM1 web over WAN links reported that using TM1 is very slow.
As we checked, they have enough bandwidth to access the service. www.cognos.com recommends 256kbit/s per TM1 session and our WAN connection available bandwidth fits this requirement.
As we further checked, we found that when data is sent to/from the TM1 server, the network packet size is very small (average is 150bytes).
For example, if an user from another country (100ms latency from our server) access TM1 web, the following happens :
User request 100KB -100ms-> Server
Server sends 150B -100ms-> User
User acknowledges -100ms-> Server
Server sends 150B -100ms-> User
User acknowledges -100ms-> Server
Server sends 150B -100ms-> User
User acknowledges -100ms-> Server
[…]
Let’s say the user wants to access 100KB of data, it will require 100*1024/150 = 683 packets + 683 acknowledgments .
Those too small packets will take ( 683 + 683 ) * 100ms = 137sec to be transferred.
I believe this is the reason why the service is slow for our users.
Normally, the packet size should be 1500bytes. In this case, the data would take 13,7sec to be transferred, which is acceptable.
I’m not sure what server parameter needs to be tuned up, but we need your suggestion for this case !
Please let me know if you need more information, as this is an urgent issue for me.
Our users accessing TM1 web over WAN links reported that using TM1 is very slow.
As we checked, they have enough bandwidth to access the service. www.cognos.com recommends 256kbit/s per TM1 session and our WAN connection available bandwidth fits this requirement.
As we further checked, we found that when data is sent to/from the TM1 server, the network packet size is very small (average is 150bytes).
For example, if an user from another country (100ms latency from our server) access TM1 web, the following happens :
User request 100KB -100ms-> Server
Server sends 150B -100ms-> User
User acknowledges -100ms-> Server
Server sends 150B -100ms-> User
User acknowledges -100ms-> Server
Server sends 150B -100ms-> User
User acknowledges -100ms-> Server
[…]
Let’s say the user wants to access 100KB of data, it will require 100*1024/150 = 683 packets + 683 acknowledgments .
Those too small packets will take ( 683 + 683 ) * 100ms = 137sec to be transferred.
I believe this is the reason why the service is slow for our users.
Normally, the packet size should be 1500bytes. In this case, the data would take 13,7sec to be transferred, which is acceptable.
I’m not sure what server parameter needs to be tuned up, but we need your suggestion for this case !
Please let me know if you need more information, as this is an urgent issue for me.