"Connection refused" after getting JSON data 100 times. How to solve?

[Di0khan]

Hi.
I'm trying to read data from Firebase RTDB, form it to String and write it to microSD card in csv file.
But after 100 readings JSONs i get "connection refused". It doesn't matter how much query.limitToFirst(5) i set. I mean 5 or 15. It stuck after 100 "Firebase.RTDB.getJSON(&fbdo, "/meteo", &query)".

Can you help me to get it in right way?

ESP32-WROOM-32 board. Arduino IDE.

My code:

  Serial.printf("Firebase Client v%s\n\n", FIREBASE_CLIENT_VERSION);
  config.api_key = API_KEY;
  auth.user.email = USER_EMAIL;
  auth.user.password = USER_PASSWORD;
  config.database_url = DATABASE_URL;
  config.token_status_callback = tokenStatusCallback;
  fbdo.setBSSLBufferSize(4096 /* Rx buffer size in bytes from 512 - 16384 */, 1024 /* Tx buffer size in bytes from 512 - 16384 */);
  fbdo.setResponseSize(4096);
  config.timeout.serverResponse = 10 * 1000;
  Firebase.begin(&config, &auth);
  Firebase.reconnectWiFi(true);
  Firebase.setDoubleDigits(5);
  Firebase.RTDB.setMaxRetry(&fbdo, 3);
  Serial.println("Getting User UID");
  while ((auth.token.uid) == "") {
    Serial.print('.');
    delay(1000);
  }
  // Print user UID
  uid = auth.token.uid.c_str();
  Serial.println("User UID: ");
  Serial.println(uid);
  
  unsigned long current_unixtime = 1698883218;

  DateTime current_day_00_ (current_unixtime);
  current_day_00_ = DateTime(current_day_00_.year(), current_day_00_.month(), current_day_00_.day(), 0, 0, 0);
  unsigned long current_day_00 = current_day_00_.unixtime();
  unsigned long next_day_00 = current_day_00 + 86400;

  unsigned int counter = 0;

  while (current_unixtime<next_day_00) {
    
    FirebaseJson json_data_;
	
    QueryFilter query;
    query.orderBy("$key");
    query.startAt(String(current_unixtime));
    query.limitToFirst(5);

    Serial.print("counter: ");
    Serial.println(counter);

    if (Firebase.ready()) {
      if (Firebase.RTDB.getJSON(&fbdo, "/meteo", &query))
      {
        counter++;

        json_data_ = fbdo.jsonObject();
        size_t len = json_data_.iteratorBegin();
        FirebaseJson::IteratorValue value;
        value = json_data_.valueAt(0);
        Serial.println(string_datatime_to_unixtime(value.key));

        for (size_t i = 0; i < len; i+=8)
        {
          value = json_data_.valueAt(i);
          Serial.printf("%d, Type: %s, Name: %s, Value: %s\n", i, value.type == FirebaseJson::JSON_OBJECT ? "object" : "array", value.key.c_str(), value.value.c_str());
          String params = "";
		  
          params += json_data_.valueAt(i).key.c_str();
          params += ",";
          String temp_string = json_data_.valueAt(i+7).value;
          params += temp_string.substring(1, (temp_string.length()-1));
          params += ",";
          params += String(json_data_.valueAt(i+5).value.toFloat(), 2);
          params += ",";
          params += String(json_data_.valueAt(i+6).value.toFloat(), 2);
          params += ",";
          params += String((json_data_.valueAt(i+6).value.toFloat()+1), 2);
          params += ",";
          params += String((json_data_.valueAt(i+5).value.toFloat()+0.5), 2);
          params += ",";
          params += String(json_data_.valueAt(i+4).value.toFloat(), 2);
          params += ",";
          params += String((json_data_.valueAt(i+4).value.toFloat()+1), 2);
          params += ",";
          params += json_data_.valueAt(i+1).value.c_str();
          params += ",";
          params += json_data_.valueAt(i+2).value.c_str();
          params += '\n';

          String dayStamp = "";
          unsigned long unixtime_i = strtoul(json_data_.valueAt(i).key.c_str(), NULL, 10);
          DateTime now = DateTime(unixtime_i);

          dayStamp += String(now.day());
          dayStamp += '-';
          dayStamp += String(now.month());
          dayStamp += '-';
          dayStamp += String(now.year());

          Serial.print("dayStamp: ");
          Serial.println(dayStamp);
          Serial.print("params: ");
          Serial.println(params);

          //to_serial_and_sd(params, dayStamp);

          current_unixtime = unixtime_i;
        }
        //Clear all list to free memory
        json_data_.iteratorEnd();
        json_data_.clear();
      }
    }
    else
    {
      // Failed to get JSON data at defined node, print out the error reason
      Serial.println("Response received");
      Serial.println(fbdo.errorReason());
    }
    // Clear all query parameters
    query.clear();

    //delay(1500);
  }
  Serial.println("---");

Firebase.RTDB.getJSON(&fbdo, "/meteo", &query) gets following data:

{"1698883218":{"ADC_VCC":0,"ADC_VCC_FLOAT":0,"bmp085pressure":101101,"bmp085temp":27.7,"si7021humidity":36.087554932,"si7021temp":27.82885498,"time":"2023-11-02 00:00:18"},"1698883252":{"ADC_VCC":0,"ADC_VCC_FLOAT":0,"bmp085pressure":101105,"bmp085temp":27.7,"si7021humidity":36.049407959,"si7021temp":27.818129883,"time":"2023-11-02 00:00:52"},"1698883288":{"ADC_VCC":0,"ADC_VCC_FLOAT":0,"bmp085pressure":101096,"bmp085temp":27.7,"si7021humidity":36.064666748,"si7021temp":27.82885498,"time":"2023-11-02 00:01:28"},"1698883323":{"ADC_VCC":0,"ADC_VCC_FLOAT":0,"bmp085pressure":101100,"bmp085temp":27.7,"si7021humidity":36.064666748,"si7021temp":27.818129883,"time":"2023-11-02 00:02:03"},"1698883357":{"ADC_VCC":0,"ADC_VCC_FLOAT":0,"bmp085pressure":101092,"bmp085temp":27.7,"si7021humidity":36.064666748,"si7021temp":27.82885498,"time":"2023-11-02 00:02:37"}}

In for loop it parsing each 8 childs and form new string "params" to write it to csv file named by dayStamp variable.

dayStamp: 2-11-2023
params: 1698883218,2023-11-02 00:00:18,36.09,27.83,28.83,36.59,27.70,28.70,0,0

But after 100 readings of "Firebase.RTDB.getJSON(&fbdo, "/meteo", &query)" i get "connection refused". And i get it again and again until i RESET my ESP32-WROOM-32 board.

[mobizt]

When the server connection established, the session was kept open for reuse.

Google limits the time to live of opened session for 40 seconds and terminated the connection.

You should call fbdo.clear() to force the session to be closed before 40 seconds after first get function was called.

[Di0khan]

OMG
mobizt, Thanks a lot !!!
It works for me.

Also. Great library. Thanks for what you doing.