Forum Discussion
Robert_47833
Altostratus
Altostratusone difficult question in irule with repect to ratio hits or "virtual pools"?
hello,dear irule
there is a irule ,with many pools and uri match on it,
such as
if { [HTTP::uri] starts_with "/test1"} {
pool CJJ-SLX1
return
}
if {[HTTP::uri] starts_with "/test2"}{
pool CJJ-SLX2
return
}
if {[URI::query [HTTP::uri]] starts_with "test3"} {
pool CJJ-SLX3
return
}
the requirement is:
we plan to create create another pools ,same blades as old pools:
CJJ-SLX1-test
CJJ-SLX2-test
CJJ-SLX3-test
rule:
------------------------------------
if it is a new request(without cookie) and match "/test1",it should go to CJJ-SLX1 and CJJ-SLX1-test per ratio(10% or something else)
if it is an old request(with cookie) and match "/test1",it should go to CJJ-SLX1-test
-------------------------------------------
not all pool should follow this rule,it is better there is some switch or config we can control which pools should follow this rule
How to change irule or anything else in bigip to meet this requirement?
thanks in advance
not an easy question
7 Replies
hoolioCirrostratus
Hi Robbie,
You can use a session cookie to track whether a request should go to a specific pool. You can set the cookie in HTTP_RESPONSE using 'HTTP::cookie insert $cookie_name value $cookie_value path / domain $domain'. You can check for the cookie in HTTP_REQUEST using [HTTP::cookie value $cookie_name].
If you want to "randomly" send x% of requests without a cookie to a specific pool, you can use rand(). The third example in this codeshare entry shows how to implement what you've described.
Example 3 - Send 90% of requests to poolA, 5% to poolB and 5% to poolC. Use a session cookie to persist clients to the same pool over their HTTP session
https://devcentral.f5.com/wiki/iRules.ratio_load_balancing_using_rand_function.ashx
If you want to prevent users from manually specifying the pool they go to, you could encrypt the cookie using a custom HTTP profile and the cookie to encryption option.
Aaron
Robert_47833hi,Aaron
thanks for your answer
1:I also want to know whether I can store this ratio in a datagroup,then other team can update this ratio in GUI
from 0% to 100%
in the ends,I wanna 100% traffic to the new pool ,while 0% to old pool ,can we achieve this?- nitass
Employee
1:I also want to know whether I can store this ratio in a datagroup,then other team can update this ratio in GUI
from 0% to 100%
in the ends,I wanna 100% traffic to the new pool ,while 0% to old pool ,can we achieve this?i do not think there is any problem in reading ratio from data group/class.
class wiki
https://devcentral.f5.com/wiki/irules.class.ashx - Robert_47833rand () =0
rand() =1.0
is it possible? - nitassThe result is always strictly greater than 0.0 and strictly less than 1.0.rand
http://www2.tcl.tk/1549 - Robert_47833it means it is impossible to reach 0 or 1.0,right?
- nitassit means it is impossible to reach 0 or 1.0,right?i think so.
