Hello, From the recent discussion about loaded backup server it looks like we do not properly assign forwarding method to connections in backup server. If backup is used in master as real server, eg. DR, then backup should use LOCALNODE for its IP. May be ip_vs_find_dest should allow real server with port 0 to be used as default server? And if real server is found its forwarding method should be used for the connection? So, backup should have the same IP and Port but it can choose to use different forwarding method? For example, master uses DR but backup TUN for the same real server. Because now when server is added its method can be converted to LOCALNODE but when such connections are created in backup server we should use DR or NAT or whatever the method is configured there. The same is when backup is added as DR server in master but the connections should be LOCALNODE when created in backup. If we still allow DR/NAT/TUN connections in backup to work without real server then all such xmitters should check RTCF_LOCAL and assume LOCALNODE if needed. This is needed for the case when we do not know the fwmark used by connection and we can not find the virtual service. Then __ip_vs_update_dest should not replace the configured forwarding method with IP_VS_CONN_F_LOCALNODE to allow backup to see this method in fwmark connections. If needed, we can remember that it is local in some new dest flag, eg. IP_VS_DEST_F_LOCAL. But better to show it as it was configured? So, how to fix these problems? May be: - ip_vs_find_dest to find svc and dest in more complex way - if backup has dest it should assign its forwarding method to the connection (ip_vs_bind_dest) - allow some transmitters to deliver traffic locally to support fwmark setups, eg. when no dest is assigned to connection There is also an option to create 2nd version of struct ip_vs_sync_conn. For example, size in struct ip_vs_sync_mesg can be moved after new field version which will be in place of size. Old backups will think the small version number as some short size and will ignore the message. New backup servers can support both formats. The new format can add new fields for fwmark, IPv6 addresses, 1 byte af (AF_INET/AF_INET6), 1 byte len for easy skipping of messages if af or protocol are not supported. Simon, may be now ip_vs_nat_xmit should see RTCF_LOCAL flag and we should check all NAT handlers to support the LOCALNODE fallback where the port can be changed too. Regards -- Julian Anastasov <ja@xxxxxx> -- To unsubscribe from this list: send the line "unsubscribe lvs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
