For more information regarding the security incident at F5, the actions we are taking to address it, and our ongoing efforts to protect our customers, click here.

Forum Discussion

Hendel's avatar
Hendel
Icon for Nimbostratus rankNimbostratus
Jan 31, 2023

Insert header when item added to ramcache

Haven't been in here for a looong time... :-7 Trying to store a header value received from pool member in a new header as that item is added to the ramcache (so it'll be present when that item is su...
application delivery
John_Alam's avatar
John_Alam
Icon for Employee rankEmployee
Feb 08, 2023

Are you using the webacceleration profile:  optimized-caching?

 

can you post any changes you may have made.

Can you include a log statement in the CACHE_UPDATE event so we can see if it is firing?

when CACHE_UPDATE {
    log local0. "Caching [HTTP::uri]"
}

Thanks.

 

 

John_Alam's avatar
John_Alam
Icon for Employee rankEmployee
Feb 08, 2023

I did some quick testing.  

1) Your iRule does not work as is, the variable 'cache' is not passed from LTM Events to Cache events.  So you will run into "variable not found" TCL errors.  I excluded that variable to continue testing.

2) I used the 'optimized-caching' profile which defaults to 'Minimum Object Size' of 0 bytes.  I could not get the header to insert, or the CACHE_UPDATE to fire, until I increased that to 1 byte.  It must be a bug of sorts.

You can see the header inserted X-LTM-Cached: test.  Note , i used a static value because as i mentioned, the variable was not transfered.

One way to transfer variable is with iRule tables.  Try passing from one event to another using a Table record.

HTH.