Forum Discussion
xiangyang_zhang
Nimbostratus
NimbostratusRead&Write problem
With the irule below, can read-write problem happen ?
rule tls_flag {
when HTTP_REQUEST {
set tlsflg 0
if {[HTTP::method] equals "CONNECT"}{
set tlsflg 1
}
}
when HTTP_REQUEST_SEND {
if { $tlsreq equals 1 } {
HTTP::disable
}
}
}
Put it with an example
1. The instance 1, a HTTP request, invoke HTTP_REQUEST, so the tlsflg will be set as 0.
2. The instance 2, a HTTPS request, invokes HTTP_REQUEST, then tlsflg is set as 1.
3. Instance 1 going to invoke HTTP_REQUEST_SEND, at this point, what value is tlsflg, 0 or 1 ?
Thanks for any information !
2 Replies
- Variables are shared within the same connection. If you want to use them across sessions, you'll have to reference them in the global namespace.
when HTTP_REQUEST { set local_var "some value" set ::global_var "some other value" log local0. "The local value is $local_var" log local0. "The global value is $::global_var" }
So, the value in the HTTP_REQUeST_SEND event will be that of the associated HTTP_REQUEST event for that connection.
Be careful about using lots of global variables as they remain resident in memory until the configuration is reloaded.
-Joe 
xiangyang_zhangMany thanks, Joe ! Your answer is always helpful and precise !
Just now I did the statistics for the hit of if-statement
Under 600TPS and at the interval of 5 minutes, the hit number on
if {[HTTP::method] equals "CONNECT"}{
set tlsflg 1
}
is about 5% higher than on
if { $tlsreq equals 1 } {
HTTP::disable
}
Under lighter load, the numbers of hit are identical.
It seems the local variable cannot keep persistent for one connection when load is higher.
