Allocated is what is currently allocated at this very moment and Max Allocated is what was the maximum amount of memory that has ever been allocated to that subsystem since the counter started.
In the example above, we can see that 10K is currently allocated for ADM Mitigation (ASM). You're probably using DoSL7 profile? APMD proxy is related to APM module.
You'd probably see similar info on tmsh show sys memory
Hope it helps.
The system itself Allocate those memory , My understanding Allocated is fixed and Max Allocate we can change is it right ?.
In memory there is an session , It means how much memory allocate to session right ?.
I don't think your understanding is correct.
The fixed allocated memory is displayed on tmsh show sys provision (or System --> Resource Provisioning in the GUI).
The output you're looking for refers to memory subsystem of TMM memory specifically.
Your box currently has 3.1G allocated for TMM usage (our data plane) and 4.6G allocated for Linux (control plane).
Out of this 3.1G it is currently using 690.5M.
From this 690.5M that TMM is using, 10K worth of objects are currently being used for ADM Mitigation and that's NOT static/fixed. From the point of view of TMM, there is no 10K hard limit.
You cannot change Max Allocated as well. Max Allocated is just the maximum amount that at some point since the counter started that Allocated ever reached.
This specific allocation is likely because you have ASM provisioned in your box and likely for BDoS protection.
With that in mind, I don't really know specifically about how the allocation of memory for ADM Mitigation subsystem is designed but my main message here is that what is displayed here is supposed to be variable with no hard limit. What you're looking for in terms of hard limit is the provisioned amount of memory for TMM and ASM under tmsh show sys provision or System --> Resource Provisioning in the GUI.
Hope it helps,