Cluster Worker Group

Description

A unique name for a group of workers.

Description

Specifies the type of external application. Choose from

• FastCGI: a FastCGI application with Responder role.
• Servlet Engine: a Servlet engine with AJPv13 connector, such as tomcat.
• HTTP Proxy: a web server or application server that supports the HTTP protocol.
• HTTPS Proxy: a web server or application server that supports the HTTPS protocol.
• LSAPI App: an application that communicates with the web server using the LSAPI protocol.

Syntax

Select from drop down list

Description

Additional HTTP protocols used to communicate with the backend server when supported. For this setting to take effect, Type must be set to HTTPS Proxy.

HTTP/1 will be used by default if no additional protocols are selected or if the selected protocols are not supported by the backend server.

Default value: All Unchecked (HTTP/1)

Syntax

Select from checkbox

Description

Specifies whether to enable this worker group.

Syntax

Select from radio box

Description

Specifies a Source IP for connecting to the backend worker. It can be overridden in worker configuration.

Syntax

Select from drop down list

Description

Specifies the priority value for the configured node group. Only useful when Strategy is set to Failover.

Default value: 100

Syntax

Integer value from 0 to 255. Higher value means higher priority.

Description

Specifies a default target port for connecting to the backend worker. It can be overriden in worker configuration.

Syntax

Integer number

Description

Specifies the maximum number of concurrent connections that can be established between the server and an external application. This setting controls how many requests can be processed concurrently by an external application, however, the real limit also depends on the external application itself. Setting this value higher will not help if the external application is not fast enough or cannot scale to a large number of concurrent requests.

Syntax

Integer number

Tips

Setting a high value does not directly translate to higher performance. Setting the limit to a value that will not overload the external application will provide the best performance/throughput.

Description

Specifies extra environment variables for the external application.

Syntax

Key=value. Multiple variables can be separated by "ENTER"

Description

Specifies the maximum time in seconds the server will wait for the external application to respond to the first request over a new established connection. If the server does not receive any data from the external application within this timeout limit, it will mark this connection as bad. This helps to identify communication problems with external applications as quickly as possible. If some requests take longer to process, increase this limit to avoid 503 error messages.

Default value: 600

Syntax

Integer number

Description

Specifies the period of time that the server waits before retrying an external application that had a prior communication problem.

Default value: 10

Syntax

Integer number

Description

Specifies whether to keep the connection open after a request has been processed. Persistent connections can increase performance, but some FastCGI external applications do not support persistent connections fully. The default is "On".

Default value: Yes

Syntax

Select from radio box

Description

Specifies the maximum time in seconds to keep an idle persistent connection open.

When set to -1, the connection will never timeout. When set to 0 or greater, the connection will be closed after this time in seconds has passed.

Default value: 30

Syntax

int

Description

Specifies whether to buffer responses received from external applications. If a "nph-" (Non-Parsed-Header) script is detected, buffering is turned off for responses with full HTTP headers.

Default value: Yes

Syntax

Select from drop down list

Description

Specifies an HTTP URL that is used to verify the availability of a web server backend worker. Has no effect to other type of workers.

Syntax

URL

Description

Specifies how often to ping a backend worker. For web server backend, an http request based on "Ping URL" will be sent. For other types of backends, an TCP connection attempt will be made to the backend server, if successful, the backend will be used as a good node.

Note: Set to 0 to disable ping.

Syntax

Integer number

Description

When set to 0, a ping is sent out at the configured Ping Interval (secs).

When set to a non-zero value, all successful requests to the backend are also counted as a ping, meaning that a standard ping will only occur when the backend has not actively served any requests at the configured Ping Interval (secs). In addition to this, when there are no open connections to the backend server, the ping interval is multiplied by the configured value effectively lengthening the configured Ping Interval (secs).

Default value: 0

Syntax

Integer value from 0 to 255.

Example

Description

Specifies the addresses of the nodes belonging to this group. Attributes that can be specified for a node are "Node Tag" (used to match "JVM Route"), "Source IP", "Destination IP", and "Destination Port". "Destination IP" address is mandatory while other attributes are optional.

Syntax

[(Node Tag)][SourceIP->]DestinationAddress[:port]

Note:(NodeTag), SourceIP->, and :port are optional here.

Note: IPv6 addresses must be surrounded by square brackets "[ ]" as seen in the following example.

Example