Best way to remove/add server from farm during LB testing

[adil.nasser3]

Hi All,

I've been tasked to assist dev team perform load balancing test.  There will be two servers in the server farm. What is the CLI command to toggle a server out of a server farm during the test?  Also what is the show command for verifying which server in the pool have the sessions?

This is the test plan:

• •1.       Open sessions to each of the Test servers to verify that they are working
• •2.       Open session to the VIP for the Test environment, and identify which server has the VIP connection
• •3.       Take down server #1 (assumed) of the Test environment
• •4.       Verify that #1 server is down, and that the VIP session switched over to #2 server with minimal interruption
• •5.       (consider interfaces to other systems)
• •6.       Start new session and verify that it goes to #2 server
• •7.       Bring up #1 server and take down #2 server
• •8.       Verify that #2 session down, and both VIP sessions switched back to #1 server
• •9.       (consider interfaces to other systems)
• •10.   Bring up #2 server

Thanks in advance,

Adil

[Kanwaljeet Singh]

Hi Adil,

To get the server out of loadbalancing equation, you can simply go to serverfarm and do "no inservice" for the server you intend to take out or you can make the probe to fail or you can simply take the server out of serverfarm by doing "no rserver .

Also, regarding your testing, if you have two servers to which traffic will be loadbalanced, connection failover will not happen. Existing connections would be dropped or RST(depending upon what you configure) and new connections would be sent to server 2.  Once the server 1 comes back up, the connections would again start getting loadbalanced to both servers. You cannot have failover of connections from 1 server to another in same serverfarm.

Let me know if you have any questions.

Regards,

Kanwal

[adil.nasser3]

Hi Fnu,

Thank you for your response.  Can you answer my last question?  It is repeated here below.

Also what is the show command for verifying which server in the pool have the sessions?

Adil

[Kanwaljeet Singh · Accepted solution]

Hi Adil,

To see which server has the connection, you can do the following:

show serverfarm detail

show conn

To me more specific you can also filter on the basis of IP address:

Example

switch/Admin# show conn address 10.150.54.216 netmask 255.255.255.255

conn-id    np dir proto vlan source                destination           state
----------+--+---+-----+----+---------------------+---------------------+------+
157045     3  in  TCP   5    10.150.54.216:49385   10.86.212.33:23       ESTAB
157455     3  out TCP   5    10.86.212.33:23       10.150.54.216:49385   ESTAB

Regards,

Kanwal

[adil.nasser3]

Thank you for your guidance!

[Kanwaljeet Singh]

Welcome! Happy to help.