When you install the SGD Gateway, default values for the maximum number of simultaneous Adaptive Internet Protocol (AIP) and HTTP connections are configured automatically, based on the available memory on the SGD Gateway host. The memory size allocated to the SGD Gateway's Java Virtual Machine (JVM) is also optimized for this number of connections.
After installing the SGD Gateway, depending on the expected number of SGD users and the number of applications they will run, you can adjust the default settings. When you do this, you might also need to adjust the JVM memory size. This process is called tuning the SGD Gateway.
If the JVM memory size is too low for the expected number of
connections, the SGD Gateway might stop working and
refuse all subsequent connections. In this case, you need to
tune the SGD Gateway so that sufficient JVM memory
is available. A java.lang.OutOfMemoryError
error message on the SGD Gateway indicates that
tuning might be required.
To tune the SGD Gateway, you do the following:
Change the maximum number of AIP connections. See Section C.1.1, “Changing the Maximum Number of AIP Connections”.
Change the maximum number of HTTP connections. See Section C.1.2, “Changing the Maximum Number of HTTP Connections”.
Change the JVM memory size. See Section C.1.3, “Changing the JVM Memory Size”.
The maximum number of AIP connections is configured at install time. The default setting depends on the memory resources available on the SGD Gateway host.
You can change this setting to a value more appropriate for your deployment. See Section C.1.1.1, “Calculating the Number of AIP Connections” for details of how to calculate the maximum number of AIP connections used by an SGD Gateway.
To change the maximum number of AIP connections, use the
--routes-aip-maxcon
option
of the gateway config edit command. For
example, to change the maximum number of AIP connections to
3000, run the following command:
# /opt/SUNWsgdg/bin/gateway config edit --routes-aip-maxcon 3000
You must restart the SGD Gateway to enable any changes you make.
The number of AIP connections used by an SGD Gateway depends on the number of concurrent SGD users, and the number of applications they run, as follows:
Number of AIP connections = (number of applications + 3) x number of SGD users
For example, an SGD Gateway with 1000 SGD users, each running four applications requires the following maximum number of simultaneous AIP connections:
(4 + 3) x 1000 = 7000 AIP connections
The maximum number of HTTP connections is configured at install time. This setting defines the maximum number of concurrent users. The default value is 100.
To change the maximum number of HTTP connections, use the
--routes-http-maxcon
option
of the gateway config edit command. For
example, to change the maximum number of HTTP connections to
200, run the following command:
# /opt/SUNWsgdg/bin/gateway config edit --routes-http-maxcon 200
You must restart the SGD Gateway to enable any changes you make.
When you change the maximum number of AIP and HTTP connections,
you might need to change the memory size allocated to the
SGD Gateway's JVM. To do this, edit the following
settings in the
/opt/SUNWsgdg/proxy/etc/tuning_parameters
file:
-Xms
– Initial memory size for the
JVM, in bytes
-Xmx
– Maximum memory size for the
JVM, in bytes
You can use the K
(kilo) and
M
(mega) modifiers with these settings. For
example: 960K = 960 kilobytes, and 512M = 512 megabytes.
See Section C.1.3.1, “Calculating the JVM Memory Size” for details of how to calculate JVM memory size values.
Ensure that your system is configured with sufficient memory resources for the JVM settings you make.
You must restart the SGD Gateway to enable any changes you make.
The amount of JVM memory used by the SGD Gateway depends on the number of simultaneous AIP connections and HTTP connections.
As each SGD Gateway connection requires approximately 300 kilobytes of JVM memory, the required JVM memory is given by:
(number of AIP connections + number of HTTP connections) x 300 kilobytes
For example, an SGD Gateway with 500 SGD users, each running two applications. The maximum number of simultaneous AIP connections is:
(2 + 3) x 500 = 2500 AIP connections
The SGD Gateway must also handle sufficient simultaneous HTTP connections to the SGD Web Server. For this example, the maximum number of HTTP connections is:
250 HTTP connections
So, the required JVM memory is:
(2500 + 250) x 300 kilobytes = 806 Megabytes, approximately.
In the
/opt/SUNWsgdg/proxy/etc/tuning_parameters
file, set the -Xms
and
-Xmx
parameters to the calculated JVM
memory value. -Xms
and
-Xmx
are normally set to be the same
value for performance reasons.