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Cluster Worker Group

Table of Contents

Layer 7 Worker Group

Name | Type | Enabled | Source IP | Default Target Port | Max Connections | Environment | Initial Request Timeout (secs) | Retry Timeout (secs) | Persistent Connection | Connection Keepalive Timeout | Response Buffering | Ping URL | Ping Interval (secs) | Node Address List

Layer 4 Worker Group

Name | Enabled | Source IP | Default Target Port | Max Connections | Initial Request Timeout (secs) | Retry Timeout (secs) | Ping Interval (secs) | Node Address List

Name

Description

A unique name for a group of workers.

Type

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

Enabled

Description

Specifies whether to enable this worker group.

Syntax

Select from radio box

Source IP

Description

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

Syntax

Select from drop down list

Default Target Port

Description

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

Syntax

Integer number

Max Connections

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.

Environment

Description

Specifies extra environment variables for the external application.

Syntax

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

Initial Request Timeout (secs)

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.

Syntax

Integer number

Retry Timeout (secs)

Description

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

Syntax

Integer number

Persistent Connection

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".

Syntax

Select from radio box

Connection Keepalive Timeout

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.

Syntax

int

Response Buffering

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.

Syntax

Select from drop down list

Ping URL

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

Ping Interval (secs)

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.

Syntax

Integer number

Node Address List

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

192.168.0.11, (node1)192.168.0.11,
(node1)192.168.0.10->192.168.0.11:80, [2a0b:4342:4000:bd::d627]