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Swarm indicates the number of replica created with the request in the Replica-Count header. Check the header value in the response to verify the correct number of replicas is received.
Swarm returns a an HTTP 412 Preconditioned Failed response if Swarm cannot locate at least two nodes in the cluster that can replicate the object. Swarm proceeds with the request if Swarm can locate a PAN and one ROW peer node.
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Responses for replicating objects
Swarm returns a an HTTP 412 Preconditioned Failed response if Swarm is replicating an object and the cluster cannot locate at least two nodes to store the replicas initially.
Swarm returns a an HTTP 201 Created response if Swarm locates one node to store the replica. Applications that need to verify the requested number of created replicas should check the Replica-Count header value to verify how many replicas were are created in the cluster.
If the requested number of replicas does not match the Replica-Count header value, repeat the request. Otherwise, the Health Processor creates the additional replicas at a later time.
To POST any unnamed object, Swarm locates two peer nodes—including the SAN—to perform the write. When two nodes are found and the writes are initiated, an immutable POST is considered a success if at least two replicas complete successfully. If Swarm cannot locate two peer nodes, the write fails and Swarm returns a an HTTP 412 Preconditioned Failed response. All other writes are considered a success if at least one replica completes successfully.