chore: make remsh node name away from the atom table overflow

bin/emqx

@@ -319,7 +319,7 @@ relx_rem_sh() {
 
 # Generate a random id
 relx_gen_id() {
-    od -t x -N 4 /dev/urandom | head -n1 | awk '{print $2}'
+    od -t u -N 4 /dev/urandom | head -n1 | awk '{print $2 % 1000}'
 }
 
 # Control a node

bin/nodetool

@@ -202,7 +202,12 @@ nodename(Name) ->
 
 this_node_name(Name) ->
     [Node, Host] = re:split(Name, "@", [{return, list}, unicode]),
-    list_to_atom(lists:concat(["remsh_maint_", Node, os:getpid(), "@", Host])).
+    list_to_atom(lists:concat(["remsh_maint_", Node, node_name_suffix_id(), "@", Host])).
+
+%% use the reversed value that from pid mod 1000 as the node name suffix
+node_name_suffix_id() ->
+    Pid = os:getpid(),
+    string:slice(string:reverse(Pid), 0, 3).
 
 %% For windows???
 create_mnesia_dir(DataDir, NodeName) ->