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<div class="moz-text-flowed" style="font-family: -moz-fixed;
font-size: 12px;" lang="x-unicode">Hi,
<br>
<br>
I have a problem with gen_tcp:recv...
<br>
The Body of the first call is missing but shows up at the second
call causing a http_error. (full code is shown a the end of the
mail)
<br>
<br>
I do a gen_tcp:connect/4 with the options
<br>
[list, {mode, list}, {reuseaddr, true}, {active, false},
{keepalive, true}, {packet, http}, {send_timeout,
timer:seconds(2)}]
<br>
<br>
Then i send a HTTP POST request using gen_tcp:send/2 and go into a
"receve loop" with gen_tcp:recv/3 until i get a {error,_} (thats
for debugging at the moment and recv timout is set to 10 seconds)
<br>
<br>
my problem is:
<br>
- On the first call (send) i get all the headers but no content.
<br>
- On the second call i get the content of the first call at the
beginning of the response causing the http_error.
<br>
<br>
<br>
I'm sending the request to a node.js service, but the result is
the same if i use a dummy apache service with the same response.
<br>
So i don't think its a problem with the Server I'm sending the
request to.
<br>
The Body of the response (aka content) is always "OK"
<br>
<br>
The received data from the first call looks like this (there is no
body with "OK", it ends with http_eoh and then a timeout after 10
seconds) :
<br>
<br>
{ok,{http_response,{1,1},200,"OK"}}
<br>
{ok,{http_header,0,"X-Powered-By",undefined,"Express"}}
<br>
{ok,{http_header,42,'Content-Type',undefined,"text/html;
charset=utf-8"}}
<br>
{ok,{http_header,38,'Content-Length',undefined,"2"}}
<br>
{ok,{http_header,3,'Date',undefined,"Tue, 10 Mar 2015 20:23:05
GMT"}}
<br>
{ok,{http_header,2,'Connection',undefined,"keep-alive"}}
<br>
{ok,http_eoh}
<br>
...after 10 seconds...
<br>
{error,timeout}
<br>
<br>
The second call then returns this (notice the OKHTTP/1.1... in the
first row, "OK" is the Body from the call before. It should be
HTTP/1.1):
<br>
<br>
{ok,{http_error,"OKHTTP/1.1 200 OK\r\n"}}
<br>
{ok,{http_error,"X-Powered-By: Express\r\n"}}
<br>
{ok,{http_error,"Content-Type: text/html; charset=utf-8\r\n"}}
<br>
{ok,{http_error,"Content-Length: 2\r\n"}}
<br>
{ok,{http_error,"Date: Tue, 10 Mar 2015 20:23:16 GMT\r\n"}}
<br>
{ok,{http_error,"Connection: keep-alive\r\n"}}
<br>
{ok,{http_error,"\r\n"}}
<br>
...after 10 seconds...
<br>
{error,timeout}
<br>
<br>
<br>
<br>
here is the gen_server code im using for my tests.
<br>
i run the test like this from the erl command line
<br>
s:start_link().
<br>
s:work(1,1). % first call without body
<br>
s:work(1,1). % second call that fails
<br>
<br>
Thanky for your help!
<br>
<br>
<br>
%%%-------------------------------------------------------------------
<br>
%%% @author mlersch
<br>
%%% @copyright (C) 2015, <COMPANY>
<br>
%%% @doc
<br>
%%%
<br>
%%% @end
<br>
%%% Created : 20. Feb 2015 11:13
<br>
%%%-------------------------------------------------------------------
<br>
-module(s).
<br>
-author("mlersch").
<br>
<br>
%% API
<br>
-compile(export_all).
<br>
<br>
-behaviour(gen_server).
<br>
<br>
%% API
<br>
-export([
<br>
start_link/0,
<br>
send/2,
<br>
reconnect/4]).
<br>
<br>
%% gen_server callbacks
<br>
-export([init/1,
<br>
handle_call/3,
<br>
handle_cast/2,
<br>
handle_info/2,
<br>
terminate/2,
<br>
code_change/3]).
<br>
<br>
-define(SERVER, ?MODULE).
<br>
<br>
-record(state, {
<br>
connection=false,
<br>
host,
<br>
port,
<br>
timeout,
<br>
opts
<br>
}).
<br>
<br>
<br>
%%%===================================================================
<br>
%%% API
<br>
%%%===================================================================
<br>
<br>
send(Processor, Data)->
<br>
gen_server:call(?MODULE, {send, Processor, Data}).
<br>
<br>
info()->
<br>
gen_server:call(?MODULE,info).
<br>
<br>
%%--------------------------------------------------------------------
<br>
%% @doc
<br>
%% Starts the server
<br>
%%
<br>
%% @end
<br>
%%--------------------------------------------------------------------
<br>
-spec(start_link() ->
<br>
{ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
<br>
start_link() ->
<br>
process_flag(trap_exit, true),
<br>
io:format("~p Start~n",[?MODULE]),
<br>
gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
<br>
<br>
%%%===================================================================
<br>
%%% gen_server callbacks
<br>
%%%===================================================================
<br>
<br>
%%--------------------------------------------------------------------
<br>
%% @private
<br>
%% @doc
<br>
%% Initializes the server
<br>
%%
<br>
%% @spec init(Args) -> {ok, State} |
<br>
%% {ok, State, Timeout} |
<br>
%% ignore |
<br>
%% {stop, Reason}
<br>
%% @end
<br>
%%--------------------------------------------------------------------
<br>
-spec(init(Args :: term()) ->
<br>
{ok, State :: #state{}} | {ok, State :: #state{}, timeout() |
hibernate} |
<br>
{stop, Reason :: term()} | ignore).
<br>
init([]) ->
<br>
<br>
State = #state{
<br>
host = "localhost",
<br>
port = 9010,
<br>
timeout = timer:seconds(2),
<br>
opts = [list, {mode, list}, {reuseaddr, true}, {active, true},
{keepalive, true}, {packet, http}, {send_timeout,
timer:seconds(2)}]
<br>
},
<br>
<br>
reconnect(State),
<br>
{ok, State}.
<br>
<br>
%%--------------------------------------------------------------------
<br>
%% @private
<br>
%% @doc
<br>
%% Handling call messages
<br>
%%
<br>
%% @end
<br>
%%--------------------------------------------------------------------
<br>
-spec(handle_call(Request :: term(), From :: {pid(), Tag ::
term()},
<br>
State :: #state{}) ->
<br>
{reply, Reply :: term(), NewState :: #state{}} |
<br>
{reply, Reply :: term(), NewState :: #state{}, timeout() |
hibernate} |
<br>
{noreply, NewState :: #state{}} |
<br>
{noreply, NewState :: #state{}, timeout() | hibernate} |
<br>
{stop, Reason :: term(), Reply :: term(), NewState :: #state{}}
|
<br>
{stop, Reason :: term(), NewState :: #state{}}).
<br>
<br>
handle_call({send, Processor, Data}, From, State) ->
<br>
<br>
% If we are offline, notify the caller
<br>
case State#state.connection of
<br>
<br>
{ok,Con}->
<br>
<br>
Request =
<br>
["POST /" ++ Processor ++ " HTTP/1.1\r\n"
<br>
++ "Content-Length: " ++
integer_to_list(lists:flatlength(Data)) ++ "\r\n"
<br>
++ "User-Agent: Erlang Client\r\n"
<br>
++ "Content-Type: application/json\r\n"
<br>
++ "Host: " ++ State#state.host ++ "\r\n"
<br>
++ "Accept: */*\r\n"
<br>
++ "\r\n", [Data]],
<br>
<br>
% Try sending the data
<br>
case send_and_receive(Con, Request) of
<br>
ok -> {reply, ok, State};
<br>
<br>
% If sending fails...
<br>
Error ->
<br>
% ...Answer the Client with a error
<br>
gen_server:reply(From, error),
<br>
io:format("~p Error: ~p~n", [?MODULE, Error]),
<br>
<br>
% ...Close the connection
<br>
gen_tcp:close(Con),
<br>
timer:sleep(500),
<br>
<br>
% ...Spawn a Process that trys to reconnect.
<br>
reconnect(State),
<br>
<br>
% ...Update the connection state
<br>
{reply, error, State#state{connection = false}}
<br>
<br>
end;
<br>
<br>
_ -> {reply, offline, State}
<br>
end;
<br>
<br>
handle_call(info, _From, State) ->
<br>
{reply, State, State};
<br>
<br>
handle_call(Request, _From, State) ->
<br>
io:format("~p CALL: ~p~n", [?MODULE, Request]),
<br>
{reply, ok, State}.
<br>
<br>
%%--------------------------------------------------------------------
<br>
%% @private
<br>
%% @doc
<br>
%% Handling cast messages
<br>
%%
<br>
%% @end
<br>
%%--------------------------------------------------------------------
<br>
-spec(handle_cast(Request :: term(), State :: #state{}) ->
<br>
{noreply, NewState :: #state{}} |
<br>
{noreply, NewState :: #state{}, timeout() | hibernate} |
<br>
{stop, Reason :: term(), NewState :: #state{}}).
<br>
handle_cast({connected, Connection}, State) ->
<br>
io:format("~p Connected: ~p~n", [?MODULE, Connection]),
<br>
{noreply, State#state{connection = Connection}};
<br>
<br>
handle_cast(Request, State) ->
<br>
io:format("~p CAST: ~p~n", [?MODULE, Request]),
<br>
{noreply, State}.
<br>
<br>
%%--------------------------------------------------------------------
<br>
%% @private
<br>
%% @doc
<br>
%% Handling all non call/cast messages
<br>
%%
<br>
%% @spec handle_info(Info, State) -> {noreply, State} |
<br>
%% {noreply, State, Timeout} |
<br>
%% {stop, Reason, State}
<br>
%% @end
<br>
%%--------------------------------------------------------------------
<br>
-spec(handle_info(Info :: timeout() | term(), State :: #state{})
->
<br>
{noreply, NewState :: #state{}} |
<br>
{noreply, NewState :: #state{}, timeout() | hibernate} |
<br>
{stop, Reason :: term(), NewState :: #state{}}).
<br>
<br>
handle_info({tcp_closed, _}, State) ->
<br>
io:format("~p Connection closed!~n", [?MODULE]),
<br>
reconnect(State),
<br>
{noreply, State#state{connection = false}};
<br>
<br>
handle_info(Info, State) ->
<br>
io:format("~p INFO: ~p~n", [?MODULE, Info]),
<br>
{noreply, State}.
<br>
<br>
%%--------------------------------------------------------------------
<br>
%% @private
<br>
%% @doc
<br>
%% This function is called by a gen_server when it is about to
<br>
%% terminate. It should be the opposite of Module:init/1 and do
any
<br>
%% necessary cleaning up. When it returns, the gen_server
terminates
<br>
%% with Reason. The return value is ignored.
<br>
%%
<br>
%% @spec terminate(Reason, State) -> void()
<br>
%% @end
<br>
%%--------------------------------------------------------------------
<br>
-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()}
| term()),
<br>
State :: #state{}) -> term()).
<br>
terminate(Reason, _State) ->
<br>
io:format("~p TERMINATE: ~p~n", [?MODULE, Reason]),
<br>
ok.
<br>
<br>
%%--------------------------------------------------------------------
<br>
%% @private
<br>
%% @doc
<br>
%% Convert process state when code is changed
<br>
%%
<br>
%% @spec code_change(OldVsn, State, Extra) -> {ok, NewState}
<br>
%% @end
<br>
%%--------------------------------------------------------------------
<br>
-spec(code_change(OldVsn :: term() | {down, term()}, State ::
#state{},
<br>
Extra :: term()) ->
<br>
{ok, NewState :: #state{}} | {error, Reason :: term()}).
<br>
code_change(_OldVsn, State, _Extra) ->
<br>
{ok, State}.
<br>
<br>
%%%===================================================================
<br>
%%% Internal functions
<br>
%%%===================================================================
<br>
<br>
<br>
<br>
%% This helper function sends the request to the server and parses
the response
<br>
%% to look in it for a status 200 code. If it finds a 200 we
return ok otherwise error.
<br>
%% by default we use active connections, when we are in idle to
get info messages about
<br>
%% deconnections into handle_info/2
<br>
%% but here we must change to passive mode, so we are able to
parse the response of this
<br>
%% send operations. disconnect messages wont show up in passive
mode but will pop up when
<br>
%% we switch bach to active mode again (even if the ocured during
passive mode).
<br>
send_and_receive(Con, Request)->
<br>
inet:setopts(Con, [{active, false}]),
<br>
Response =
<br>
case gen_tcp:send(Con, Request) of
<br>
ok -> parse_response(Con);
<br>
E -> E
<br>
end,
<br>
inet:setopts(Con, [{active, true}]),
<br>
Response.
<br>
<br>
<br>
parse_response(Con)->parse_response(Con, error).
<br>
parse_response(Con, State)->
<br>
R = gen_tcp:recv(Con, 0, timer:seconds(10)),
<br>
io:format("PR: ~p~n",[R]),
<br>
case R of
<br>
{ok,{http_response,_,200,_}} -> parse_response(Con, ok);
<br>
{ok,http_eoh} ->
<br>
io:format("PRX: ~p~n",[gen_tcp:recv(Con, 0,
timer:seconds(10))]),
<br>
State;
<br>
{error, E} -> {error, E};
<br>
_ -> parse_response(Con, State)
<br>
end.
<br>
<br>
reconnect(State)->
<br>
spawn_link(?MODULE, reconnect, [self(), State,
calendar:local_time(), 1]).
<br>
<br>
reconnect(Pid, State, Started, Tries)->
<br>
io:format("~p Connecting to host ~p on port ~p~n",[?MODULE,
State#state.host, State#state.port]),
<br>
case gen_tcp:connect(State#state.host, State#state.port,
State#state.opts, State#state.timeout) of
<br>
{ok, Connection} ->
<br>
io:format("~p Reconnect changing controlling process:
~p~n",[?MODULE, gen_tcp:controlling_process(Connection, Pid)]),
<br>
gen_server:cast(?MODULE, {connected, {ok, Connection}});
<br>
E -> io:format("~p Reconnection failed ~p (Tried it ~p
times since ~p). Waiting 2sec. till retry!~n", [?MODULE, E, Tries,
Started]),
<br>
timer:sleep(timer:seconds(2)),
<br>
reconnect(Pid, State, Started, Tries+1)
<br>
end.
<br>
<br>
<br>
<br>
%%%===================================================================
<br>
%%% Debug stuff
<br>
%%%===================================================================
<br>
loop(Max)->
<br>
lists:foreach(fun(_)->
<br>
timer:sleep(100),
<br>
spawn(fun()->
<br>
send("processgaac",
"{\"_id\":{\"$oid\":\"53B382F4BE53EE3946137430\"},\"sid\":\"07101a57ce294750bb36fa72e2ffab5d\",\"eid\":1566,\"cd\":{\"$date\":1404273396000},\"t\":\"gaac\",\"p\":{\"ua\":\"Mozilla/5.0
(Windows NT 6.3; WOW64; rv:30.0) Gecko/20100101
Firefox/30.0\",\"pt\":\"search_result\",\"rt\":\"internal\",\"gs\":[{\"g\":\"08006309\",\"p\":1650},{\"g\":\"04431464\",\"p\":1429},{\"g\":\"03932773\",\"p\":696},{\"g\":\"07563999\",\"p\":825},{\"g\":\"09100275\",\"p\":5089},{\"g\":\"06426800\",\"p\":2240},{\"g\":\"10417853\",\"p\":1180},{\"g\":\"02096458\",\"p\":1365},{\"g\":\"08798173\",\"p\":3897},{\"g\":\"03531850\",\"p\":1243},{\"g\":\"00188357\",\"p\":412},{\"g\":\"09296203\",\"p\":2495},{\"g\":\"05566143\",\"p\":1498},{\"g\":\"08006456\",\"p\":1467},{\"g\":\"04347717\",\"p\":2199},{\"g\":\"08006410\",\"p\":4499},{\"g\":\"09374110\",\"p\":3897},{\"g\":\"04187656\",\"p\":691},{\"g\":\"05010397\",\"p\":1075},{\"g\":\"07727923\",\"p\":493}],\"cats\":[\"1100068\",\"1100068\",\"1100068\",\"1100071\",\"1100043\",\"1100015\",\"1100015\",\"1100029\",\"1100355\",\"1100355\",\"1100196\",\"1100114\",\"1100013\",\"1100021\",\"1100021\",\"1100021\",\"1100021\",\"1100021\",\"1100170\",\"1571\",\"1100014\",\"1100117\",\"1100233\",\"1100107\",
\"1100096\",\"1100467\",\"1100094\",\"1100094\",\"1100013\",\"1100014\",\"1100014\",\"1100029\",\"1100015\",\"1100015\",\"1100017\",\"1100463\",\"1100034\",\"1100109\",\"1440\",\"1100114\",\"1100109\",\"1440\",\"1100177\",\"1100013\",\"1100191\",\"1100094\",\"1100191\",\"1100029\",\"1100029\",\"1100048\",\"1100043\",\"1100016\",\"1100210\",\"1100016\",\"1100463\",\"1226\"],\"catsc\":[\"AR02AA16\",\"79680\",\"22172\",\"30365\",\"AR01AC03\",\"24009\",\"79658\",\"66403\",\"30365\",\"22294\",\"BX01\",\"71445\",\"81085\",\"24510\",\"30365\",\"22294\",\"AD11AX01\",\"82323\",\"30365\",\"22294\",\"30365\",\"22294\",\"BB03Z\",\"81644\",\"81629\",\"25123\",\"22183\",\"22182\",\"30365\",\"30365\",\"BB01A\",\"24577\",\"66407\",\"30365\",\"AD01AE16\",\"30365\",\"AD08AC\",\"24512\",\"22206\",\"30365\",\"AN05CX\",\"81736\",\"22192\",\"30365\",\"BB03Z\",\"77677\",\"66409\",\"66407\",\"30365\",\"BX01\",\"71446\",\"79609\",\"22171\",\"30365\",\"BC01D\",\"30365\",\"BB03D\",\"82323\",\"25125\",\"22204\",
\"30365\",\"22294\",\"AD11AX01\",\"82997\",\"82323\",\"25125\",\"22204\",\"32455\",\"30365\",\"22294\",\"BB03Z\",\"24783\",\"81736\",\"81083\",\"81082\",\"81087\",\"39604\",\"30365\",\"AS01GX07\",\"24009\",\"22220\",\"22196\",\"79610\",\"30365\",\"22294\",\"BC01D\",\"24728\",\"30365\",\"23432\",\"30365\"],\"catsx\":[\"30365\",\"30365\",\"22294\",\"30365\",\"22294\",\"82323\",\"30365\",\"22294\",\"30365\",\"22294\",\"30365\",\"30365\",\"30365\",\"30365\",\"30365\",\"30365\",\"77677\",\"30365\",\"30365\",\"30365\",\"82323\",\"30365\",\"22294\",\"82997\",\"82323\",\"30365\",\"22294\",\"39604\",\"30365\",\"30365\",\"22294\",\"30365\",\"23432\",\"30365\"],\"fpid\":\"/aktionsartikel\",\"lt\":\"list\",\"lp\":1},\"r\":{\"s\":[{\"slid\":\"high\",\"cid\":2498,\"scr\":100000000,\"f\":1}]},\"ti\":200000000,\"to\":false,\"at\":53596,\"dv\":8,\"agg\":[],\"pad\":\"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\"}")<br>
end)
<br>
end,
<br>
lists:seq(1,Max)).
<br>
<br>
work(Loops, Max)->
<br>
lists:foreach(fun(_)-> spawn(s,loop,[Max])
end,lists:seq(1,Loops)).
<br>
<br>
<div class="moz-txt-sig"><span class="moz-txt-tag">-- <br>
</span>________________________________________
<br>
Matthias Lersch, Senior Software Architect
<br>
Tel.: +49 69 972 69 197; Fax: +49 69 972 69 204; Email: <a
class="moz-txt-link-abbreviated"
href="mailto:matthias.lersch@kairion.de">matthias.lersch@kairion.de</a>
<br>
Kairion GmbH, Gutleutstraße 30, D-60329 Frankfurt
<br>
Internet: <a class="moz-txt-link-freetext"
href="http://www.kairion.de">http://www.kairion.de</a>
<br>
<br>
<br>
</div>
</div>
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</html>