ESP8266HTTPClient error -1

[Loucotolo]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• I have tested that the issue is present in current master branch (aka latest git).
• I have searched the issue tracker for a similar issue.
• If there is a stack dump, I have decoded it.
• I have filled out all fields below.

Platform

• Hardware: [ESP8266EX]
• Core Version: [2.5.2]
• Development Env: [Arduino IDE]
• Operating System: [Windows]

Settings in IDE

• Module: [Generic ESP8266 Module]
• Flash Mode: [DOUT (COMPATIBLE)]
• Flash Size: [1MB]
• lwip Variant: [v2 Lower Memory]
• Reset Method: [ck]
• Flash Frequency: [40Mhz]
• CPU Frequency: [80Mhz]
• Upload Using: [SERIAL]
• Upload Speed: [115200]
• Espressif FW: [nono-sdk 2.2.1]

Problem Description

Hello, I have the following problem:
I am using a esp8266, via an httpclient to connect to a server, but after some time (random), it returns me the following error:
httpCode: -1 (Connection Refused). With wireshark I noticed that it [TCP PORT numbers reused] 57490-> 8000 [SYN].

I would like to know what I am doing wrong in my code to receive this error.

[Sketch]

#include <Arduino.h>
#include <ESP8266WiFi.h> /// fix http://blog.flynnmetrics.com/uncategorized/esp8266-exception-3/
#include <ESP8266HTTPClient.h>
//#include <WiFiClient.h>
#include <ESPAsyncWebServer.h>
#include <ArduinoJson.h>
#include <ESP8266httpUpdate.h>
#include <Hash.h>
#include <FS.h>
#include <user_interface.h> //Biblioteca necessaria para acessar os Timer`s.

#include "OneButton.h" // https://github.com/mathertel/OneButton
#include <EEPROM.h>
#include <WiFiUdp.h>


bool connect2WiFI()
{


  WiFi.setAutoReconnect( true );

#if (ADEBUG == 1 )
  Serial.printf("Wifi State changed to %s\n", WlStatusToStr(WiFi.status()));
#endif

  
  WiFi.persistent(false);   // Solve possible wifi init errors (re-add at 6.2.1.16 #4044, #4083)
  WiFi.disconnect(true);    // Delete SDK wifi config
  delay(200);
  WiFi.mode(WIFI_STA);      // Disable AP mode
  WiFi.setSleepMode(WIFI_MODEM_SLEEP);  // Disable sleep (Esp8288/Arduino core and sdk default)
  
  WiFi.begin("DEMO", "DEMO");


  uint32_t AwifiTimeout = 20000;
  uint32_t maxTime = millis() + AwifiTimeout;


  while ((WiFi.status()  != WL_CONNECTED) && (millis() < maxTime)) {
    yield();
  }


  if (WiFi.status()  != WL_CONNECTED)
  {

    return false;
  }


  Serial.println(WiFi.localIP());         // Send the IP address of the ESP8266 to the computer



  return true;

}


bool test()
{

more_send_data:

  int txlen = 0;


  

  WiFiClient client;

  HTTPClient http;

  http.setTimeout(500); // 500ms
  String md_ip = "192.168.0.31";
  String md_port = "8000";
  String path = "http://" + md_ip + ":" + md_port + "/index.php";

  const char * headerkeys[] = {"Set-Cookie", "Cookie"} ;
  size_t headerkeyssize = sizeof(headerkeys) / sizeof(char*);

  http.begin(client, path);    //Specify request destination
  //  http.begin(path);
  http.addHeader("Content-Type", "application/json");  //Specify content-type header


  http.collectHeaders(headerkeys, headerkeyssize);

  int httpCode = http.POST("Hello");  //Send the request
  String payload = http.getString();                                        //Get the response payload




  if (httpCode > 0)
  {

    if (httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_MOVED_PERMANENTLY) {




      http.end();  //Close connection



      return true;







    } // end  payload != ""

    client.stop();
    http.end();  //Close connection


    return true;
  }






  Serial.print("httpCode:");
  Serial.println(httpCode, DEC );
  



  
  http.end();  //Close connection
  return false;
}


void setup() {
  // put your setup code here, to run once:

  WiFi.mode(WIFI_STA);


  EEPROM.begin(512);


  Serial.begin(115200);
connect2WiFI();
}



void loop() {
  // put your main code here, to run repeatedly:


  test();


  delay(500);
}

Debug Messages

16:33:26.338 -> 192.168.0.192
16:33:34.254 -> pm open,type:2 0
16:33:37.970 -> httpCode:-1

wireshark report :
https://mega.nz/#!jJ4wRIyQ!6ayDTjoxEgaxO82yBo-0I4PwqH33TpPVC9XijBe2EXg

[devyte]

Please don't post links to external sources, especially to files uploaded, because there is no assurance the files will live in the future. Instead, reduce the log by filtering out unrelevant things (if you haven't already done so) and post the log directly here with markup.

[jpboucher]

You are probably running out of sockets after a while. Try calling http.setReuse(true) before you call http.begin

[d-a-v]

Same sketch is running flawlessly here.
I think your server is busy for more than 0.5 seconds and the esp times out as you asked it to.

Failing request starts:

17:33:37.439458 IP 192.168.0.192.49882 > 192.168.0.31.8000: Flags [S], seq 6630, win 2144, options [mss 536,nop,nop,sackOK], length 0
17:33:37.439571 IP 192.168.0.31.8000 > 192.168.0.192.49882: Flags [S.], seq 1154906697, ack 6631, win 65392, options [mss 1460,nop,nop,sackOK], length 0

lots of https at the same time:

17:33:37.623692 IP 149.11.65.227.https > 192.168.0.31.49821: Flags [P.], seq 22745748:22745784, ack 1, win 34, length 36
17:33:37.623693 IP 149.11.65.227.https > 192.168.0.31.49821: Flags [P.], seq 22745784:22746194, ack 1, win 34, length 410
17:33:37.623694 IP 149.11.65.227.https > 192.168.0.31.49821: Flags [P.], seq 22746194:22746230, ack 1, win 34, length 36
... (lots)
17:33:37.868468 IP 192.168.0.31.49821 > 149.11.65.227.https: Flags [.], ack 22752711, win 1024, length 0
17:33:37.916391 IP 149.11.65.227.https > 192.168.0.31.49821: Flags [P.], seq 22752711:22753078, ack 1, win 34, length 367
17:33:37.916445 IP 192.168.0.31.49821 > 149.11.65.227.https: Flags [.], ack 22753078, win 1023, length 0

esp times out:

17:33:37.944117 IP 192.168.0.192.49882 > 192.168.0.31.8000: Flags [R.], seq 1, ack 3140060599, win 24584, length 0

next requests are honored:

...
17:33:38.446020 IP 192.168.0.192.50004 > 192.168.0.31.8000: Flags [S], seq 6642, win 2144, options [mss 536,nop,nop,sackOK], length 0
17:33:38.446099 IP 192.168.0.31.8000 > 192.168.0.192.50004: Flags [S.], seq 1775072509, ack 6643, win 65392, options [mss 1460,nop,nop,sackOK], length 0
17:33:38.448943 IP 192.168.0.192.50004 > 192.168.0.31.8000: Flags [.], ack 1, win 2144, length 0
17:33:38.454408 IP 192.168.0.192.50004 > 192.168.0.31.8000: Flags [P.], seq 1:206, ack 1, win 2144, length 205
17:33:38.454408 IP 192.168.0.192.50004 > 192.168.0.31.8000: Flags [P.], seq 206:211, ack 1, win 2144, length 5
17:33:38.454437 IP 192.168.0.31.8000 > 192.168.0.192.50004: Flags [.], ack 211, win 65182, length 0
17:33:38.455149 IP 192.168.0.31.8000 > 192.168.0.192.50004: Flags [P.], seq 1:231, ack 211, win 65182, length 230
17:33:38.455223 IP 192.168.0.31.8000 > 192.168.0.192.50004: Flags [F.], seq 231, ack 211, win 65182, length 0
17:33:38.469175 IP 192.168.0.192.50004 > 192.168.0.31.8000: Flags [R.], seq 211, ack 232, win 24584, length 0
...

Be nicer with your server, increase ESP timeout.

[TD-er]

@jpboucher

You are probably running out of sockets after a while. Try calling http.setReuse(true) before you call http.begin

I've looked into the code and it seems it does keep the connection open.
What's the default for max. open connections?
What will happen if that maximum is hit?

[jpboucher]

@jpboucher

You are probably running out of sockets after a while. Try calling http.setReuse(true) before you call http.begin

I've looked into the code and it seems it does keep the connection open.
What's the default for max. open connections?
What will happen if that maximum is hit?

The default is 5. It can be increased up to 15 using espconn_tcp_set_max_con() from the ESP SDK.
If the maximum is hit, you will not be able to create a new socket and the connection will fail. The request will return HTTPC_ERROR_CONNECTION_REFUSED (-1)

[d-a-v]

I've looked into the code and it seems it does keep the connection open.

It doesn't. Variable scope implies the destructor is called and the connection closed at every loop (on test() ending, because WiFiClient and HTTPClient are declared in there).

The default is 5. It can be increased up to 15 using espconn_tcp_set_max_con() from the ESP SDK.

We don't depend on that. It's for espconn API. Your only limitation is RAM.

[jpboucher]

My bad. Since everything is indeed cleared at every loop I would also suspect that the server is too slow.

[TD-er]

It doesn't. Variable scope implies the destructor is called and the connection closed at every loop (on test() ending, because WiFiClient and HTTPClient are declared in there).

I meant the code of HTTPClient.
So as long as the client object does exist, it will keep the connection open so it seems. (with _reuse set)

[devyte]

This was reported for 2.5.2. There have been several critical stability fixes merged since then. Please retest with 2.6.3 or latest git.

[earlephilhower]

Closing as last update was Jun 18, there have been many HTTPClient updates, and there's been no response to @devyte's request for a confirmation this is still an issue in 2.7+ for ~4 months. If it does still show up in latest master, please open a new bug with MCVE/etc. so we can look at it.

[beicnet]

@earlephilhower , @devyte The issue with -1 still persists, went today from 2.3.0 to 2.7.1, but it's got worse, now I have delay, freezing issues too.

This function is called every 10 seconds:

void checkForUpdates()
{
  if (WiFi.status() == WL_CONNECTED) {
    String fwVerURL = "";
    fwVerURL.concat("http://");
    fwVerURL.concat("xxxxxx.ddns.net");
    fwVerURL.concat(":");
    fwVerURL.concat("80");
    fwVerURL.concat("/xxx/version.asp");
   
    HTTPClient updHttp;
    updHttp.setReuse(true);
    updHttp.begin(fwVerURL);

    int httpCode = updHttp.GET();

    Serial.println("HTTP Respose Code: " + String(httpCode));

    if (httpCode == 200) {
      String newFwTmpVersion = updHttp.getString();
      // ===> Here I got 3 second whole ESP freezing <===
      Serial.println("HTTP Update Version: " + newFwTmpVersion);
    } else {
      Serial.println("Error HTTP Update!");
    }
    updHttp.end();
  }
}

[earlephilhower]

@beicnet, Can you please open a new issue with MCVE (and public file maybe on your GH acct or something so we can run it in our own environments) and also enable full debugging to get more useful logs? This is a closed issue from a long time ago, so it won't get attention otherwise.

[beicnet]

Hey @earlephilhower thank you for your fast response! ;)

MCVE? Huh, there are 12 library included in my project, and also there are a lot of modules attached to the WeMos D1 mini board.

Can you tell me which one is the full debug in Tools > Debug level?

I'm still using Arduino 1.8.2 with 2.3.0 and everything was fine except that HTTP random response -1, and -2 code (as we speak I got -11 too).