From baaabb217737750d8e8732c00f269ca55a42a667 Mon Sep 17 00:00:00 2001
From: Christopher <chris@entropealabs.com>
Date: Thu, 16 Apr 2020 08:27:05 -0500
Subject: [PATCH] add some logging around live callee lookups

---
 lib/router/session.ex | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/lib/router/session.ex b/lib/router/session.ex
index 978144e..36be7f7 100644
--- a/lib/router/session.ex
+++ b/lib/router/session.ex
@@ -740,17 +740,27 @@ defmodule Wampex.Router.Session do
     end
   end
 
-  defp get_live_callee(_proxy, [], _index, 0), do: {:error, :no_live_callees}
-  defp get_live_callee(_proxy, [], _index, _), do: {:error, :no_live_callees}
+  defp get_live_callee(_proxy, [], _index, 0) do
+    Logger.error("No live callees, tried all replicas")
+    {:error, :no_live_callees}
+  end
+
+  defp get_live_callee(_proxy, [], _index, _) do
+    Logger.error("No live callees, empty result from lookup")
+    {:error, :no_live_callees}
+  end
 
   defp get_live_callee(proxy, callees, index, tries) when is_list(callees) do
     {_id, {pid, node}} = c = Enum.at(callees, index)
+    Logger.info("Seeing if live callee #{pid} on node #{node} is up...")
 
     case GenServer.call({proxy, node}, {:is_up, pid}) do
       true ->
         c
 
       false ->
+        Logger.error("#{pid} on #{node} is not live, trying next")
+
         index =
           case index + 1 do
             ni when ni < length(callees) -> ni
@@ -761,7 +771,10 @@ defmodule Wampex.Router.Session do
     end
   end
 
-  defp get_live_callee(_proxy, _, _index, _), do: {:error, :no_live_callees}
+  defp get_live_callee(_proxy, _, _index, _) do
+    Logger.error("No live callees, something odd happened")
+    {:error, :no_live_callees}
+  end
 
   defp send_to_peer(msg, transport, pid) do
     transport.send_request(pid, remove_nil_values(msg))
-- 
2.45.3