diff --git a/src/node/shell/distributed_db.ml b/src/node/shell/distributed_db.ml
index dc2ebd230..9b93542f9 100644
--- a/src/node/shell/distributed_db.ml
+++ b/src/node/shell/distributed_db.ml
@@ -162,7 +162,7 @@ module Raw_operation_hashes = struct
     Make_raw
       (struct
         type t = Block_hash.t * int
-        let name = "raw_operation_hash"
+        let name = "operation_hashes"
         let pp ppf (h, n) = Format.fprintf ppf "%a:%d" Block_hash.pp h n
         let encoding =
           let open Data_encoding in
@@ -231,7 +231,7 @@ module Raw_operations = struct
     Make_raw
       (struct
         type t = Block_hash.t * int
-        let name = "raw_operation"
+        let name = "operations"
         let pp ppf (h, n) = Format.fprintf ppf "%a:%d" Block_hash.pp h n
         let encoding =
           let open Data_encoding in
@@ -390,7 +390,9 @@ module P2p_reader = struct
   let handle_msg global_db state msg =
 
     let open Message in
-    let open Logging.Node.Worker in
+    let module Logging =
+      Logging.Make(struct let name = "node.distributed_db.p2p_reader" end) in
+    let open Logging in
 
     lwt_debug "Read message from %a: %a"
       P2p.Peer_id.pp_short state.gid Message.pp_json msg >>= fun () ->
@@ -575,7 +577,7 @@ module P2p_reader = struct
                 Raw_operations.Table.notify
                   net_db.operations_db.table state.gid
                   (block, ofs) (ops, path) >>= fun () ->
-        Lwt.return_unit
+                Lwt.return_unit
 
   let rec worker_loop global_db state =
     Lwt_utils.protect ~canceler:state.canceler begin fun () ->
diff --git a/src/node/shell/distributed_db_functors.ml b/src/node/shell/distributed_db_functors.ml
index c50635b5e..d6e24125e 100644
--- a/src/node/shell/distributed_db_functors.ml
+++ b/src/node/shell/distributed_db_functors.ml
@@ -238,7 +238,12 @@ module type REQUEST = sig
 end
 
 module Make_request_scheduler
-    (Hash : sig type t end)
+    (Hash : sig
+       type t
+       val name : string
+       val encoding : t Data_encoding.t
+       val pp : Format.formatter -> t -> unit
+     end)
     (Table : MEMORY_TABLE with type key := Hash.t)
     (Request : REQUEST with type key := Hash.t) : sig
 
@@ -249,6 +254,8 @@ module Make_request_scheduler
 
 end = struct
 
+  include Logging.Make(struct let name = "node.distributed_db.scheduler." ^ Hash.name end)
+
   type key = Hash.t
   type param = Request.param
 
@@ -268,12 +275,20 @@ end = struct
   let request t p k =
     t.push_to_worker (Request (p, k))
   let notify t p k =
+    debug "push received %a from %a"
+      Hash.pp k P2p.Peer_id.pp_short p ;
     t.push_to_worker (Notify (p, k))
   let notify_invalid t p k =
+    debug "push received invalid %a from %a"
+      Hash.pp k P2p.Peer_id.pp_short p ;
     t.push_to_worker (Notify_invalid (p, k))
   let notify_duplicate t p k =
+    debug "push received duplicate %a from %a"
+      Hash.pp k P2p.Peer_id.pp_short p ;
     t.push_to_worker (Notify_duplicate (p, k))
   let notify_unrequested t p k =
+    debug "push received unrequested %a from %a"
+      Hash.pp k P2p.Peer_id.pp_short p ;
     t.push_to_worker (Notify_unrequested (p, k))
 
   type worker_state = {
@@ -297,13 +312,22 @@ end = struct
         state.pending infinity in
     let now = Unix.gettimeofday () in
     let delay = next -. now in
-    if delay <= 0. then Lwt.return_unit else Lwt_unix.sleep delay
+    if delay <= 0. then Lwt.return_unit else begin
+      (* lwt_debug "waiting at least %.2fs" delay >>= fun () -> *)
+      Lwt_unix.sleep delay
+    end
+
+  let may_pp_peer ppf = function
+    | None -> ()
+    | Some peer -> P2p.Peer_id.pp_short ppf peer
 
   (* TODO should depend on the ressource kind... *)
   let initial_delay = 0.1
 
   let process_event state now = function
     | Request (peer, key) -> begin
+        lwt_debug "registering request %a from %a"
+          Hash.pp key may_pp_peer peer >>= fun () ->
         try
           let data = Table.find state.pending key in
           let peers =
@@ -315,6 +339,8 @@ end = struct
             next_request = min data.next_request (now +. initial_delay) ;
             peers ;
           } ;
+          lwt_debug "registering request %a from %a -> replaced"
+            Hash.pp key may_pp_peer peer >>= fun () ->
           Lwt.return_unit
         with Not_found ->
           let peers =
@@ -326,14 +352,28 @@ end = struct
             next_request = now ;
             delay = initial_delay ;
           } ;
+          lwt_debug "registering request %a from %a -> added"
+            Hash.pp key may_pp_peer peer >>= fun () ->
           Lwt.return_unit
       end
-    | Notify (_gid, key) ->
+    | Notify (peer, key) ->
         Table.remove state.pending key ;
+        lwt_debug "received %a from %a"
+          Hash.pp key P2p.Peer_id.pp_short peer >>= fun () ->
         Lwt.return_unit
-    | Notify_invalid _
-    | Notify_unrequested _
-    | Notify_duplicate _ ->
+    | Notify_invalid (peer, key) ->
+        lwt_debug "received invalid %a from %a"
+          Hash.pp key P2p.Peer_id.pp_short peer >>= fun () ->
+        (* TODO *)
+        Lwt.return_unit
+    | Notify_unrequested (peer, key) ->
+        lwt_debug "received unrequested %a from %a"
+          Hash.pp key P2p.Peer_id.pp_short peer >>= fun () ->
+        (* TODO *)
+        Lwt.return_unit
+    | Notify_duplicate (peer, key) ->
+        lwt_debug "received duplicate %a from %a"
+          Hash.pp key P2p.Peer_id.pp_short peer >>= fun () ->
         (* TODO *)
         Lwt.return_unit
 
@@ -342,6 +382,7 @@ end = struct
     and timeout = compute_timeout state in
     Lwt.choose [ (state.events >|= fun _ -> ()) ; timeout ; shutdown ] >>= fun () ->
     if Lwt.state shutdown <> Lwt.Sleep then
+      lwt_debug "terminating" >>= fun () ->
       Lwt.return_unit
     else if Lwt.state state.events <> Lwt.Sleep then
       let now = Unix.gettimeofday () in
@@ -350,6 +391,7 @@ end = struct
       Lwt_list.iter_s (process_event state now) events >>= fun () ->
       worker_loop state
     else
+      lwt_debug "timeout" >>= fun () ->
       let now = Unix.gettimeofday () in
       let active_peers = Request.active state.param in
       let requests =
@@ -379,6 +421,13 @@ end = struct
                  P2p_types.Peer_id.Map.add requested_peer requests acc)
           state.pending P2p_types.Peer_id.Map.empty in
       P2p_types.Peer_id.Map.iter (Request.send state.param) requests ;
+      P2p_types.Peer_id.Map.fold begin fun peer request acc ->
+        acc >>= fun () ->
+        Lwt_list.iter_s (fun key ->
+            lwt_debug "requested %a from %a"
+              Hash.pp key P2p.Peer_id.pp_short peer)
+          request
+      end requests Lwt.return_unit >>= fun () ->
       worker_loop state
 
   let create param =
diff --git a/src/node/shell/distributed_db_functors.mli b/src/node/shell/distributed_db_functors.mli
index 083f4ce20..d11625c85 100644
--- a/src/node/shell/distributed_db_functors.mli
+++ b/src/node/shell/distributed_db_functors.mli
@@ -101,7 +101,12 @@ module type REQUEST = sig
 end
 
 module Make_request_scheduler
-    (Hash : sig type t end)
+    (Hash : sig
+       type t
+       val name : string
+       val encoding : t Data_encoding.t
+       val pp : Format.formatter -> t -> unit
+     end)
     (Table : MEMORY_TABLE with type key := Hash.t)
     (Request : REQUEST with type key := Hash.t) : sig