link warn : connection already connected

[zx-ai]

I try to use 4 nics link like this:
std::string name = topo_.prefill_nodes[i].local_ip +":12345@mlx5_0";
std::string name1 = topo_.prefill_nodes[i].local_ip +":12345@mlx5_1";
// std::string name2 = topo_.prefill_nodes[i].local_ip +":12345@mlx5_2";
// std::string name3 = topo_.prefill_nodes[i].local_ip +":12345@mlx5_3";
RdmaTransport* rdmaport = dynamic_cast<RdmaTransport*>(xport_);
std::vector<std::shared_ptr> context = rdmaport->get_context_list();
for(auto temp : context)
{
auto endpoint = (*temp).endpoint(name);
endpoint->setupconnectionsByActive();
auto endpoint1 = (*temp).endpoint(name1);
endpoint1->setupConnectionsByActive();
// auto endpoint2 = (*temp).endpoint(name2);
// endpoint1->setupconnectionsByActive();
// auto endpoint3 = (*temp).endpoint(name3);
}
Why, when two machines each use two network cards to establish connections, do they not need to re-establish connections for data transmission? However, when each machine uses four network cards, warnings occur during connection establishment（ connection already connected）, and endpoint connections are created during data transmission. What causes this? Is it possible to establish all endpoint connections before transmitting data?

[alogfans]

A endpoint can be connection-established either by active or passive. For example, when mlx5_0 starts to get connected with mlx5_2, mlx5_0 creates a connection to mlx5_2, and mlx5_2 also creates a connection to mlx5_0. Later, if mlx5_0 starts to get connected with mlx5_0, there will be duplicated connections.