diff --git a/ocaml/xapi-idl/lib/observer_helpers.ml b/ocaml/xapi-idl/lib/observer_helpers.ml
index 125ba101722..24f7ee3db46 100644
--- a/ocaml/xapi-idl/lib/observer_helpers.ml
+++ b/ocaml/xapi-idl/lib/observer_helpers.ml
@@ -241,24 +241,10 @@ module Server (Impl : Server_impl) () = struct
   let process call = Idl.Exn.server S.implementation call
 end
 
-let rec retry_econnrefused f =
-  try f () with
-  | Unix.Unix_error (Unix.ECONNREFUSED, "connect", _) ->
-      (* debug "Caught ECONNREFUSED; retrying in 5s"; *)
-      Thread.delay 5. ; retry_econnrefused f
-  | e ->
-      (* error "Caught %s: does the observer service need restarting?"
-         (Printexc.to_string e); *)
-      raise e
-
 module Client = ObserverAPI (Idl.Exn.GenClient (struct
-  open Xcp_client
-
   let rpc call =
-    retry_econnrefused (fun () ->
-        if !use_switch then
-          json_switch_rpc queue_name call
-        else
-          xml_http_rpc ~srcstr:(get_user_agent ()) ~dststr:queue_name uri call
+    Xcp_client.(
+      retry_and_switch_rpc call ~use_switch:!use_switch ~queue_name
+        ~dststr:queue_name ~uri
     )
 end))
diff --git a/ocaml/xapi-idl/lib/xcp_client.ml b/ocaml/xapi-idl/lib/xcp_client.ml
index 435a63e3126..a7ebd1f996a 100644
--- a/ocaml/xapi-idl/lib/xcp_client.ml
+++ b/ocaml/xapi-idl/lib/xcp_client.ml
@@ -190,3 +190,21 @@ let binary_rpc string_of_call response_of_string ?(srcstr = "unset")
 
 let json_binary_rpc =
   binary_rpc Jsonrpc.string_of_call Jsonrpc.response_of_string
+
+let rec retry_econnrefused f =
+  try f () with
+  | Unix.Unix_error (Unix.ECONNREFUSED, "connect", _) ->
+      (* debug "Caught ECONNREFUSED; retrying in 5s"; *)
+      Thread.delay 5. ; retry_econnrefused f
+  | e ->
+      (* error "Caught %s: does the service need restarting?"
+         (Printexc.to_string e); *)
+      raise e
+
+let retry_and_switch_rpc call ~use_switch ~queue_name ~dststr ~uri =
+  retry_econnrefused (fun () ->
+      if use_switch then
+        json_switch_rpc queue_name call
+      else
+        xml_http_rpc ~srcstr:(get_user_agent ()) ~dststr uri call
+  )
diff --git a/ocaml/xapi-idl/rrd/rrd_client.ml b/ocaml/xapi-idl/rrd/rrd_client.ml
index abb12a118de..08a9b731f71 100644
--- a/ocaml/xapi-idl/rrd/rrd_client.ml
+++ b/ocaml/xapi-idl/rrd/rrd_client.ml
@@ -13,26 +13,12 @@
  *)
 
 open Rrd_interface
-open Xcp_client
-
-let rec retry_econnrefused f =
-  try f () with
-  | Unix.Unix_error (Unix.ECONNREFUSED, "connect", _) ->
-      (* debug "Caught ECONNREFUSED; retrying in 5s"; *)
-      Thread.delay 5. ; retry_econnrefused f
-  | e ->
-      (* error "Caught %s: does the rrd service need restarting?"
-         (Printexc.to_string e); *)
-      raise e
 
+(* TODO: use_switch=false as the message switch doesn't handle raw HTTP very well *)
 let rpc call =
-  retry_econnrefused (fun () ->
-      (* TODO: the message switch doesn't handle raw HTTP very well *)
-      if (* !use_switch *) false then
-        json_switch_rpc !queue_name call
-      else
-        xml_http_rpc ~srcstr:(get_user_agent ()) ~dststr:"rrd" Rrd_interface.uri
-          call
+  Xcp_client.(
+    retry_and_switch_rpc call ~use_switch:false ~queue_name:!queue_name
+      ~dststr:"rrd" ~uri
   )
 
 module Client = RPC_API (Idl.Exn.GenClient (struct let rpc = rpc end))
diff --git a/ocaml/xapi-idl/storage/storage_client.ml b/ocaml/xapi-idl/storage/storage_client.ml
index b66636daf6a..eeb0e765170 100644
--- a/ocaml/xapi-idl/storage/storage_client.ml
+++ b/ocaml/xapi-idl/storage/storage_client.ml
@@ -13,25 +13,11 @@
  *)
 
 open Storage_interface
-open Xcp_client
 
-let rec retry_econnrefused f =
-  try f () with
-  | Unix.Unix_error (Unix.ECONNREFUSED, "connect", _) ->
-      (* debug "Caught ECONNREFUSED; retrying in 5s"; *)
-      Thread.delay 5. ; retry_econnrefused f
-  | e ->
-      (* error "Caught %s: does the storage service need restarting?"
-         (Printexc.to_string e); *)
-      raise e
-
-module Client = Storage_interface.StorageAPI (Idl.Exn.GenClient (struct
+module Client = StorageAPI (Idl.Exn.GenClient (struct
   let rpc call =
-    retry_econnrefused (fun () ->
-        if !use_switch then
-          json_switch_rpc !queue_name call
-        else
-          xml_http_rpc ~srcstr:(get_user_agent ()) ~dststr:"storage"
-            Storage_interface.uri call
+    Xcp_client.(
+      retry_and_switch_rpc call ~use_switch:!use_switch ~queue_name:!queue_name
+        ~dststr:"storage" ~uri
     )
 end))