There may be web browsing delays if there is a gap on the maximum concurrent connections between the downstream proxy and upstream proxy of IWSS/IWSVA.
In an environment with multiple proxies, the amount of maximum connections should be monitored since this may cause delays since each proxy has a different default value of concurrent connections.
IWSVA has an automatic tuning feature which allows an acceptable amount of concurrent connections that depends on the OS resources. If there is amount of requests which goes over the acceptable amount of concurrent connections, IWSVA returns a "503 Service Unavailable" response to the client.
To expand the concurrent connections, OS resources must be added for automatic tuning.
The following are spec information on how many connections IWSVA can handle on each OS resource with automatic tuning.
|OS Resource||8 GB Memory||12 GB Memory||16 GB Memory||24 GB Memory||32 GB Memory|
|4 CPUs||3 (9000)||4 (12000)||4 (12000)||4 (12000)||4 (12000)|
|6 CPUs||3 (9000)||4 (12000)||6 (18000)||6 (18000)||6 (18000)|
|8 CPUs||3 (9000)||4 (12000)||6 (18000)||8 (24000)||8 (24000)|
|12 CPUs||3 (9000)||4 (12000)||6 (18000)||9 (27000)||12 (36000)|
- The above means “number of processes (Maximum concurrent connections)”. One process can handle up to 3000 connections. For example, three processes serve a total of 9000 concurrent connections.
- Less than 2 CPUs or 7 GB memory will be adjusted into 2 processes.
Customizing acceptable concurrent connection is not allowed except of automatic tuning.
You may choose to modify the upstream or downstream proxy configuration (if possible) in order to align it with IWSVA's concurrent connections.