What is happening is extremely frustrating.
We recently upgrade our Junos on SRX650 from 10.2R3.10 to 10.4R9.1, and deploy a few servers.
All the sudden, that network becomes extremely slow.
Here is what we have in this network
2x SRX650 in cluster running 10.4R9.1 with Web ,App and DB security zones.
2x EX4200 in chassis running 10.2R3.10
2 App servers in App zone
2 Web VM servers in Web zone
3 DB servers in DB zone.
All the network connectivity seems slow between servers, through site-site VPN back to our main office.