Retry when pool is full

Fixes adrienmo#28 and obsoletes PR adrienmo#29.

Retry is implemented for query, but not for query_noreply. Perhaps it should.

Author: zuiderkwast

src/eredis_cluster.erl

@@ -372,6 +372,7 @@ query_noreply(Command, PoolKey) ->
     Transaction = fun(Worker) -> qw_noreply(Worker, Command) end,
     {Pool, _Version} = eredis_cluster_monitor:get_pool_by_slot(Slot),
     eredis_cluster_pool:transaction(Pool, Transaction),
+    %% TODO: Retry if pool is full?
     ok.
 
 query(_, _, ?REDIS_CLUSTER_REQUEST_TTL) ->
@@ -407,6 +408,10 @@ handle_transaction_result(Result, Version) ->
         {error, tcp_closed} ->
             retry;
 
+	%% Pool is full
+	{error, full} ->
+	    retry;
+
         %% Other TCP issues
         %% See reasons: https://erlang.org/doc/man/inet.html#type-posix
         {error, Reason} when is_atom(Reason) ->

src/eredis_cluster_pool_worker.erl

@@ -36,6 +36,8 @@ init(Args) ->
 
     {ok, #state{conn=Conn}}.
 
+query(full, _Commands) ->
+    {error, full};
 query(Worker, Commands) ->
     gen_server:call(Worker, {'query', Commands}).