http keepalive on CSS

Unanswered Question
Aug 27th, 2008
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users should able to access "http://virtual IP on the CSS/app/login.jsp", and on my CSS, I want to change to http keepalive from default ICMP, here is my config:

service Server2

ip address 10.122.49.18

keepalive type http

keepalive port 80

keepalive uri "/app/login.jsp"

active


after that, when I did "show keepalive", it show me "down" status:

Name: AUTO_Server2 Index: 2 State: Down

Description: Auto generated for service Server2

Address: 10.122.49.18 Port: 80

Type: HTTP:HEAD:/app/login.jsp

Keepalive Error: General failure

Encryption: Disabled

Frequency: 5

Max Failures: 3

Retry Frequency: 5

Dependent Services:

Server2

where is the problem, what else I need to do?

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Overall Rating: 2.7 (3 ratings)
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Syed Iftekhar Ahmed Wed, 08/27/2008 - 22:14
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You can try to add "keepalive type http non-persistent" command and see if it works.


If it doesn't work then please post the output from the following commands....


CSS# llama

CSS(debug)# icp probe service server2 "/app/login.jsp"

CSS(debug)# icp probe host 10.122.49.18 "/app/login.jsp"



Syed Iftekhar Ahmed


shibindong Wed, 08/27/2008 - 22:55
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thanks for your reply!

I actually configured 2 hosts:

!************************** SERVICE **************************

service Server1

ip address 10.122.49.17

keepalive type http

keepalive port 80

keepalive uri "/"

keepalive method get

active


service Server2

ip address 10.122.49.18

keepalive type http

keepalive port 80

keepalive uri "/"

keepalive method get

active


!*************************** OWNER ***************************

owner L3_Owner


content L3_Rule

add service Server1

add service Server2

vip address 10.122.49.23

balance aca

advanced-balance cookies

active


!*************************** GROUP ***************************

group server1

vip address 10.122.49.23

add destination service Server1

add destination service Server2

active


but from the debug info, it looks different...

CSS11503(debug)# icp probe host 10.122.49.17

Probing 10.122.49.17:80(-) Probing SSL..


CSS11503(debug)# icp probe host 10.122.49.18

Probing 10.122.49.18:80(-) KeepAlive probe (5)

IP Address: 10.122.49.18

Port: 80

URL: /

HTTP Version: 1.1

Server Model: Microsoft-IIS/6.0

Server Date: Thu, 28 Aug 2008 06:51:32 GMT

HEAD Response: 401 Unauthorized

HEAD Support: Yes

Persistence: Yes

Keep-Alive: No

Request Depth: 14

TBR: Unknown

Connect Time: 1 ms

Rqst/Rsp Time: 1 ms

Pipeline: No

SSL: No


Syed Iftekhar Ahmed Wed, 08/27/2008 - 23:15
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By default the HTTP keepalive will look for a response code of 200 and if anything different is received it will mark the server down.


The uri you are probing is returning 401 (HEAD Response: 401 Unauthorized ),thats the reason service is declared down by css.


Instead of probing the auth page you should ask your app people to give you some other uri to probe.


Another option would be add these two lines under service config


keepalive http-rspcode 401

keepalive type http non-persistent


Above commands will ensure that if CSS get 401 response then it should mark the service UP.


Thanks

Syed Iftekhar Ahmed

shibindong Wed, 08/27/2008 - 23:24
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here is the configure I added:

!************************** SERVICE **************************

service Server1

ip address 10.122.49.17

keepalive port 80

keepalive uri "/"

keepalive method get

keepalive type http non-persistent

keepalive http-rspcode 401

active


service Server2

ip address 10.122.49.18

keepalive port 80

keepalive uri "/"

keepalive method get

keepalive type http non-persistent

keepalive http-rspcode 401

active


!*************************** OWNER ***************************

owner L3_Owner

content L3_Rule

add service Server1

add service Server2

vip address 10.122.49.23

balance aca

advanced-balance cookies

active


!*************************** GROUP ***************************

group server1

vip address 10.122.49.23

add destination service Server1

add destination service Server2

active

and my question is why I got different result for this 2 servers?


CSS11503# llama

CSS11503(debug)# icp probe host 10.122.48.18

Probing 10.122.48.18:80(-) KeepAlive probe (3)

IP Address: 10.122.48.18

Port: 80

URL: /

HTTP Version: 1.1

Server Model: Microsoft-IIS/7.0

Server Date: Thu, 28 Aug 2008 07:22:19 GMT

HEAD Response: 200 OK

HEAD Support: Yes

Persistence: Yes

Keep-Alive: No

Request Depth: 14

TBR: Unknown

Hash: dfbd1ee66a4e792349591b88660c0956

Connect Time: 1 ms

Rqst/Rsp Time: 1 ms

Pipeline: No

SSL: No


CSS11503(debug)# icp probe host 10.122.48.17

Probing 10.122.48.17:80(-) KeepAlive probe..

IP Address: 10.122.48.17

Port: 80

URL: /

HTTP Version: 1.1

Server Model: Microsoft-IIS/7.0

Server Date: Thu, 28 Aug 2008 07:22:22 GMT

HEAD Response: 200 OK

HEAD Support: Yes

Persistence: Yes

Keep-Alive: No

Request Depth: 14

TBR: Unknown

Hash: dfbd1ee66a4e792349591b88660c0956

Connect Time: 1 ms

Rqst/Rsp Time: 1 ms

Pipeline: No

SSL: No


CSS11503(debug)# exit

CSS11503# sh keepalive

keepalive Show Keepalives

keepalive-summary Show summary info on all keepalives


CSS11503# sh keepalive-

Keepalives:

AUTO_nexthop00004 State: Alive 10.122.49.1

AUTO_Server1 State: Alive 10.122.49.17

AUTO_Server2 State: Down 10.122.49.18


CSS11503#

Syed Iftekhar Ahmed Wed, 08/27/2008 - 23:28
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With CSS I dont recommend

"keepalive method get"

Unless you really need it

change it to

"keepalive method head"


with method GET CSS calculates a HASH value for the page and mark the server down if there is a slight change in the page.


Since you have changed th uri to "/" and as per ICP its returning 200. GEt rid of the following command


keepalive http-rspcode 401



Syed Iftekhar Ahmed

shibindong Thu, 08/28/2008 - 00:46
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I remove the 401 command, and created a webpage under root directory of web server, and confgured the "keepalive uri" point to that page. and it works.

thanks for help!

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