Collective Member

Collective Member

This feature enables a server to be a member of a management collective.

Enable this feature

To enable the Collective Member feature, add the following element declaration inside the featureManager element in the server.xml file:
<feature>collectiveMember-1.0</feature>

Developing a feature that depends on this feature

If we are developing a feature that depends on the Collective Member feature, include the following item in the Subsystem-Content header in the feature manifest file for the new feature:
com.ibm.websphere.appserver.collectiveMember-1.0; type="osgi.subsystem.feature"

Features that this feature enables

JMX REST Connector

Java Servlets 3.0

Features that enable this feature

SPI packages provided by this feature

com.ibm.wsspi.collective.repository

com.ibm.wsspi.collective.repository.publisher

Feature configuration elements

We can use the following elements in the server.xml file to configure the Collective Member feature:

collectiveMember

failoverController

hostAuthInfo

hostSingleton

collectiveMember

The collective member configuration requires at least one collective controller address (identified by controllerHost and controllerPort). The collective controller can have multiple available addresses. Add one or more failoverController elements to identify the additional controllers. When multiple controllers are available, the member connects to one of the controllers. If the connection to the controller ends unexpectedly, the member connects to another controller in the remaining set of controllers.

Attribute name Data type Default value Description
controllerHost string The host name for the collective controller instance.
controllerPort int The port for the JMX/REST connector, typically the HTTPS port.
controllerReadTimeout A period of time with millisecond precision 300s The read timeout for member connection to the collective controller. A longer read timeout may be necessary in large or geographically dispersed topologies. Minimum value is 2 minutes. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. We can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.
heartBeatInterval A period of time with millisecond precision 60s Periodic time interval at which the collective member will contact the collective controller to indicate liveness. Minimum value is 1 second. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. We can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.

collectiveMember > failoverController

Description: An additional collective controller address which is available for the collective member to use.

Required: false

Data type:

Attribute name Data type Default value Description
host string The host name for the collective controller instance.
port int The port for the JMX/REST connector, typically the HTTPS port.

hostAuthInfo

Connection details to allow for the collective controller to authenticate to the server's host.

Attribute name Data type Default value Description
rpcHost string localhost The fully qualified host name or IP address. A '*' wildcard will result in host name detection; this is not recommended for multi-homed systems and may result in unexpected behaviour. The host name must be unique within the network and must be the host name on which the remote connection protocol is listening (SSH, or OS specific RPC). This value will inherit from the defaultHostName variable if not set. The host name set here will directly control where the server's information is stored within the collective controller repository.
rpcPort int 22 The port on which the remote connection protocol is listening (SSH, or OS specific RPC). See product documentation for supported RPC mechanisms.
rpcUser string The operating system user ID to use to connect to the host.
rpcUserHome string The home directory of the user login ID. Only required to be set if sudo is to be used and SSH generation is to be done automatically.
rpcUserPassword Reversably encoded password (string) The password for the operating system user. If this property is not set, key-based authentication will be used. Use of key-based authentication is recommended for hosts which support SSH. If this property is set and sshPrivateKeyPath is also set, the key will take precedence.
sshPrivateKeyPassword Reversably encoded password (string) The password for the SSH private key.
sshPrivateKeyPath string The path to the SSH private key file. If the key pair does not exist, a key pair will be generated automatically. The private key is required for key-based authentication.
sshPublicKeyPath string The path to the SSH public key file. If the key pair does not exist, a key pair will be generated automatically. The public key will be placed into the configured userId's authorized_keys file if it is not present. Setting the path to the public key is not required.
sudoUser string The sudo user ID. This property should not be set when useSudo=false.
sudoUserPassword Reversably encoded password (string) The password for the sudo user. This property should not be set when useSudo=false.
useHostCredentials boolean If true, then the product uses the RPC credentials of the host to invoke commands and ignores other parameters in the 'Host Authentication Information' element.
useSudo boolean If true, then sudo will be used to invoke commands. The user to sudo as can be controlled by setting sudoUser attribute. If sudoUser is not set, then the user to sudo as will be the configured default sudo user for the host. If this property is not set, and either sudoUser or sudoUserPassword are set, then useSudo is assumed to be true. If false, and either sudoUser or sudoUserPassword are set, then a warning will be printed and the sudo options will be ignored.

hostSingleton

Host singleton elector configuration

Attribute name Data type Default value Description
name string * The name of the singleton. A '*' wildcard is the default value and indicates this configuration applies to all singletons in this server.
port int 0 The port to use for host singleton leader elections. A value of 0 is the default and means that no election will occur. In this case, the singleton in each member will be its own leader.

Attribute name	Data type	Default value	Description
controllerHost	string		The host name for the collective controller instance.
controllerPort	int		The port for the JMX/REST connector, typically the HTTPS port.
controllerReadTimeout	A period of time with millisecond precision	300s	The read timeout for member connection to the collective controller. A longer read timeout may be necessary in large or geographically dispersed topologies. Minimum value is 2 minutes. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. We can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.
heartBeatInterval	A period of time with millisecond precision	60s	Periodic time interval at which the collective member will contact the collective controller to indicate liveness. Minimum value is 1 second. Specify a positive integer followed by a unit of time, which can be hours (h), minutes (m), seconds (s), or milliseconds (ms). For example, specify 500 milliseconds as 500ms. We can include multiple values in a single entry. For example, 1s500ms is equivalent to 1.5 seconds.

Attribute name	Data type	Default value	Description
host	string		The host name for the collective controller instance.
port	int		The port for the JMX/REST connector, typically the HTTPS port.

Attribute name	Data type	Default value	Description
rpcHost	string	localhost	The fully qualified host name or IP address. A '*' wildcard will result in host name detection; this is not recommended for multi-homed systems and may result in unexpected behaviour. The host name must be unique within the network and must be the host name on which the remote connection protocol is listening (SSH, or OS specific RPC). This value will inherit from the defaultHostName variable if not set. The host name set here will directly control where the server's information is stored within the collective controller repository.
rpcPort	int	22	The port on which the remote connection protocol is listening (SSH, or OS specific RPC). See product documentation for supported RPC mechanisms.
rpcUser	string		The operating system user ID to use to connect to the host.
rpcUserHome	string		The home directory of the user login ID. Only required to be set if sudo is to be used and SSH generation is to be done automatically.
rpcUserPassword	Reversably encoded password (string)		The password for the operating system user. If this property is not set, key-based authentication will be used. Use of key-based authentication is recommended for hosts which support SSH. If this property is set and sshPrivateKeyPath is also set, the key will take precedence.
sshPrivateKeyPassword	Reversably encoded password (string)		The password for the SSH private key.
sshPrivateKeyPath	string		The path to the SSH private key file. If the key pair does not exist, a key pair will be generated automatically. The private key is required for key-based authentication.
sshPublicKeyPath	string		The path to the SSH public key file. If the key pair does not exist, a key pair will be generated automatically. The public key will be placed into the configured userId's authorized_keys file if it is not present. Setting the path to the public key is not required.
sudoUser	string		The sudo user ID. This property should not be set when useSudo=false.
sudoUserPassword	Reversably encoded password (string)		The password for the sudo user. This property should not be set when useSudo=false.
useHostCredentials	boolean		If true, then the product uses the RPC credentials of the host to invoke commands and ignores other parameters in the 'Host Authentication Information' element.
useSudo	boolean		If true, then sudo will be used to invoke commands. The user to sudo as can be controlled by setting sudoUser attribute. If sudoUser is not set, then the user to sudo as will be the configured default sudo user for the host. If this property is not set, and either sudoUser or sudoUserPassword are set, then useSudo is assumed to be true. If false, and either sudoUser or sudoUserPassword are set, then a warning will be printed and the sudo options will be ignored.

Attribute name	Data type	Default value	Description
name	string	*	The name of the singleton. A '*' wildcard is the default value and indicates this configuration applies to all singletons in this server.
port	int	0	The port to use for host singleton leader elections. A value of 0 is the default and means that no election will occur. In this case, the singleton in each member will be its own leader.