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When a message comes to the "Failover" state, it will go through its list of endpoints to pick the first one in "Active" or "Timeout" state. Then it will send the message using that particular endpoint. If an error occurs while sending the message, the failover will go through the endpoint list again from the beginning and will try to send the message using the first endpoint.
Some errors put the endpoint into "Timeout" and some keep the endpoint in the "Active" state. In these cases, the retry can happen using the same endpoint. If the failure occurs with the first endpoint within the failover group and this error does not put the endpoint into Suspended state, the retry will happen using the same endpoint.
Failover gives priority to the first endpoint that is not in the Suspended state. So it will send the message through the first endpoint in the failover group, as long as it is not "Suspendedsuspended. " When the first endpoint is "Suspendedsuspended, " it will send the requests using the second endpoint. When the first endpoint becomes ready to send again, it will try again on the first endpoint, even though the second endpoint is still active.
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Here the Sample_First endpoint is marked as "Timeout" if a connection times out, closes, or sends IO errors. For all the other errors, it will be marked as " Suspended. " When this error occurs, the failover will retry using the first non "Suspended" suspended endpoint. In this case, it is the same endpoint (Sample_First). It will retry until the retry count becomes 0. The retry happens in parallel. Since messages come to this endpoint using many threads, the same message may not be retried three times. Another message may fail and can reduce the retry count.
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