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| Sun Java System Message Queue 3 2005Q4 Administration Guide | |
Chapter 16
Administered Object Attribute ReferenceThis chapter provides reference information about the attributes of administered objects. It consists of the following sections:
Connection Factory AttributesThe attributes of a connection factory object are grouped into categories described in the following sections below:
Connection Handling
Table 16-1 lists the connection factory attributes for connection handling.
Table 16-1 Connection Factory Attributes for Connection Handling
Attribute
Type
Default
Description
imqAddressList
String
An existing Message Queue 3.0 address, if any; if none, the first entry in Table 16-2
List of broker addresses
The list consists of one or more message server addresses, separated by commas. Each address specifies (or implies) the host name, port number, and connection service for a broker instance to which the client can connect. Address syntax varies depending on the connection service and port assignment method; see below for details.
imqAddressListBehavior
String
PRIORITY
Order in which to attempt connection to server addresses:
PRIORITY Order specified in address list
RANDOM Random order
NOTE: If many clients share the same connection factory, specify random connection order to prevent them from all attempting to connect to the same address.
imqAddressListIterations
Integer
5
Number of times to iterate through address list attempting to establish or reestablish a connection
A value of -1 denotes an unlimited number of iterations.
imqPingInterval
Integer
30
Interval, in seconds, at which to test connection between client and broker
A value of 0 or -1 disables periodic testing of the connection.
imqReconnectEnabled
Boolean
false
Attempt to reestablish a lost connection?
imqReconnectAttempts
Integer
0
Number of times to attempt connection (or reconnection) to each address in address list before moving on to next
A value of -1 denotes an unliimited number of connection attempts; attempt repeatedly to connect to first address until successful.
imqReconnectInterval
Long integer
3000
Interval, in milliseconds, between reconnection attempts
This value applies both for successive attempts on a given address and for successive addresses in the list.
NOTE: Too small a value may give the broker insufficient recovery time; too large a value may cause unacceptable connection delays.
imqSSLIsHostTrusted
Boolean
true
Accept broker’s self-signed authentication certificate?
NOTE: To use signed certificates from a certificate authority, set this attribute to false.
The value of the imqAddressList attribute is a comma-separated string specifying one or more message server addresses to which to connect. The general syntax for each address is as follows:
scheme://address
where scheme identifies one of the addressing schemes shown in the first column of Table 16-2 and address denotes the server address itself. The exact syntax for specifying the address depends on the addressing scheme, as shown in the last column of the table.
Table 16-3 shows examples of the various address formats.
Client Identification
Table 16-4 lists the connection factory attributes for client identification.
Reliability and Flow Control
Table 16-5 lists the connection factory attributes for reliability and flow control.
Table 16-5 Connection Factory Attributes for Reliability and Flow Control
Attribute
Type
Default
Description
imqAckTimeout
String
0
Maximum time, in milliseconds, to wait for broker acknowledgment before throwing an exception
A value of 0 denotes no timeout (wait indefinitely).
NOTE: In some situations, too low a value can cause premature timeout: for example, initial authentication of a user against an LDAP user repository using a secure (SSL) connection can take more than 30 seconds.
imqConnectionFlowCount
Integer
100
Number of payload messages in a metered batch
Delivery of payload messages to the client is temporarily suspended after this number of messages, allowing any accumulated control messages to be delivered. Payload message delivery is resumed on notification by the client runtime, and continues until the count is again reached.
A value of 0 disables metering of message delivery and may cause Message Queue control messages to be blocked by heavy payload message traffic.
imqConnectionFlowLimitEnabled
Boolean
false
Limit message flow at connection level?
imqConnectionFlowLimit
Integer
1000
Maximum number of messages per connection to deliver and buffer for consumption
Message delivery on a connection stops when the number of unconsumed payload messages pending (subject to flow metering governed by imqConnectionFlowCount) exceeds this limit. Delivery resumes only when the number of pending messages falls below the limit. This prevents the client from being overwhelmed with pending messages that might cause it to run out of memory.
This attribute is ignored if imqConnectionFlowLimitEnabled is false.
imqConsumerFlowLimit
Integer
100
Maximum number of messages per consumer to deliver and buffer for consumption
Message delivery to a given consumer stops when the number of unconsumed payload messages pending for that consumer exceeds this limit. Delivery resumes only when the number of pending messages for the consumer falls below the percentage specified by imqConsumerFlowThreshold. This canbe used to improve load balancing among multiple consumers and prevent any single consumer from starving others on the same connection.
This limit can be overridden by a lower value set for a queue’s own consumerFlowLimit attribute (see Chapter 15, "Physical Destination Property Reference"). Note also that message delivery to all consumers on a connection is subject to the overall limit specified by imqConnectionFlowLimit.
imqConsumerFlowThreshold
Integer
50
Number of messages per consumer buffered in the client runtime, as a percentage of imqConsumerFlowLimit, below which to resume message delivery
Queue Browser and Server Sessions
Table 16-6 lists the connection factory attributes for queue browsing and server sessions.
Setting Standard Message Properties
The connection factory attributes listed in Table 16-7 control whether the Message Queue client runtime sets certain standard message properties defined in the Java Message Service Specification.
Message Header Overrides
Table 16-8 lists the connection factory attributes for overriding JMS message header fields.
Destination AttributesTable 16-9 lists the attributes that can be set for a destination administered object.
SOAP Endpoint AttributesTable 16-10 lists the attributes used to configure endpoint URLs for applications that use the Simple Object Access Protocol (SOAP); see the Message Queue Developer’s Guide for Java Clients for more information.