Multiple Endpoints (for replicated SOAP Servers) with SAVON

Question

I am trying to make a SOAP request to a remote SOAP Server using the Savon gem in rails. The SOAP Server is replicated on three instances with different IP Addresses, i.e. XXX.XXX.XXX.1, XXX.XXX.XXX.2 and XXX.XXX.XXX.3.

I am able to explicitly define the savon client endpoint using one of the above ip addresses like so:

Savon.client(
    endpoint: "http://XXX.XXX.XXX.1:15043/enmac/SOAP",
    namespace: '',
    convert_request_keys_to: :camelcase,
    env_namespace: 'SOAP-ENV',
    namespace_identifier: nil,
    log: true,
    log_level: :info,
    pretty_print_xml: true,
    read_timeout: 90,
    open_timeout: 90,
    headers: {
        "Accept-Encoding" => "gzip"
    }
)

The problem with the above sample code is that when the SOAP Server instance with IP Address XXX.XXX.XXX.1 is down then my services goes down as well.

What I am actually looking for is an approach that will make sure that when SOAP Server instance XXX.XXX.XXX.1 is down then XXX.XXX.XXX.2 takes over etc.

Below is what I tried but couldn't get it to work properly:

1. I have a database table with all the SOAP Servers instances populated by IP address with only a single of them with a status of active

2. I have a the following method that shift to then next server:

     def shift_oms_server
         @oms_server = OmsServer.where(status: true).first
         case @oms_server.ip_address.to_s
             when 'XXX.XXX.XXX.1'
               @oms_server.update_attribute(:status, false)
               @next_oms_server = OmsServer.where(ip_address: 'XXX.XXX.XXX.2').first
               @next_oms_server.update_attribute(:status, true)
             when 'XXX.XXX.XXX.2'
               @oms_server.update_attribute(:status, false)
               @next_oms_server = OmsServer.where(ip_address: 'XXX.XXX.XXX.3').first
               @next_oms_server.update_attribute(:status, true)
             when 'XXX.XXX.XXX.3'
               @oms_server.update_attribute(:status, false)
               @next_oms_server = OmsServer.where(ip_address: 'XXX.XXX.XXX.1').first
               @next_oms_server.update_attribute(:status, true)
         end
     end
   

3. Now I modify my Savon Client initialization like so:

       @oms_server = OmsServer.where(status: true).first
       Savon.client(
               endpoint: "http://#{@oms_server.ip_address.to_s}:15043/enmac/SOAP",
               namespace: '',
               convert_request_keys_to: :camelcase,
               env_namespace: 'SOAP-ENV',
               namespace_identifier: nil,
               log: true,
               log_level: :info,
               pretty_print_xml: true,
               read_timeout: 90,
               open_timeout: 90,
               headers: {
                   "Accept-Encoding" => "gzip"
               }
           )
   
      

4. Finally wherever I make the SOAP Request call I will have something like a begin rescue block like so:

      begin
        # make soap server request
      rescue HTTPServerException => e
        shift_oms_server
        # make soap server request
      ensure
        shift_oms_server
        # make soap server request
      end
     

Forgive my English. The approach above didn't work for me. I will be happy if someone could enlighten me where I went wrong with the above approach or provide a direction to a more simpler and efficient approach.

Ideally I would like to know if it is possible to have more than one endpoints defined using the Savon gem, if yes how?

Thanks in advance.