Progress Sonic ESB Configuration and Management Guide

Reconnection
Fault Tolerant Connections and Reconnection
Progress Sonic ESB endpoints appear as SonicMQ clients. From the perspective of
SonicMQ, the ESB reconnect implementation is a customized client reconnect
implementation.
Progress Sonic ESB always tries to reconnect when a connection fails, regardless of
whether the faultTolerant connection parameter is set to true or false.
The following sections explain how initial connections are created and how interrupted
connections are reconnected.
Initial Connections
The initialConnectTimeout value specifies for how many seconds an ESB endpoint will
try to establish an initial connection. This value is the total time during which the initial
connection is attempted, not the time spent attempting to connect to each URL. This
means that some URLs in the URL list might not be attempted. For non-fault tolerant
connections, this parameter is ignored and the endpoint tries each URL once.
Note Two special timeout values, 0 and -1, are available in SonicMQ but are not available in
Progress Sonic ESB, where configurations are limited to a value range of 1-3600.
If the SonicMQ initial connection cannot be established within the timeout period, the
Progress Sonic ESB reconnect logic will retry. This retry looks like the initial connection
attempt to the SonicMQ implementation. The retry starts trying to establish connections
again, starting with the first URL in the initial connection list. The Progress Sonic ESB
retry will continue until the container is shut down.
Interrupted Connections
The faultTolerantReconnectTimeout value specifies how many seconds an ESB endpoint
will allow for reconnecting a broken connection to the primary or backup broker using the
fault tolerant mechanism. If the connection is re-established before the timeout expires,
the endpoint will not be connected to a broker outside the original fault tolerant pair.
If the connection is not re-established within the reconnect timeout period, SonicMQ
signals that the connection failed and the Sonic ESB reconnect logic tries to create a new
connection using the initial connection process described previously. In this case, it is
possible that a connection can be established to a broker that is not a member of the
original fault tolerant pair.
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