Can the number of SUBSCRIBE more than 4? ( uMQTT 3.1 )

[ShinDaiIchi]

It's very good work!

When I try uMQTT3.1 commit, (uMQTT3.1.1 can't run well for me)
I found that SUBSCRIBE has limit only 4 subscribes.
Can more subscribes?

Thank you.

[martin-ger]

The v3.1.1 seems to have a problem, will view into this next week, currentl I am on a business trip.

The number of Subscriber has three limitations: he number of WiFi clients on the internal AP is restricted to 8, the number of TCP connections has a limit in the lwip (maybe 4-5 as default) and the table of subscribed topics is limited (currently 50, user_main()).

You probably refere to the second limitation. Will try to compile a version with 8-10) TCP-clients next week.

[svilex]

@martin-ger Is the LmacRxBlk:1 error related to the number of TCP connections? I keep getting this error spammed in the serial monitor console. I googled it but i still can't figure out what it really means.

Links2004/arduinoWebSockets#57
esp8266/Arduino#2176
esp8266/Arduino#928

[TridentTD]

I found problem like this too.

When I try on uMQTT3.1.1 broker and with MQTT-SPY (mqtt client 3.1.1/3.1)
I can connected to broker ONLY 5 differenct "mqtt-client id" on the same ip connected to wifi.

Thank you.

[martin-ger]

espconn_tcp_get_max_con() gives you by default 5.
Acording to the SDK this can be increased espconn_tcp_set_max_con(). Tried with 10 - actually I managed 6 before memory shortage occured. So I guess 5 is more or less the maximum.

[TridentTD]

I tried by recompile with espconn_tcp_get_max_con(10) , however can only 5 clients

Feature request

• more than 10 clients
• bridge uMQTT to outside (on Internet) Broker.

Thank you again.

[svilex]

@TridentTD If by client do you mean the device connected to the ap:

• espconn_tcp_get_max_con() Just returns an uint8 and doesn't have any argument
• Maybe do you mean espconn_tcp_set_max_con(). Anyway, this function isn't related to the number of clients. What are you looking for i think is this
• Keep in mind the esp has its own hardware limitations

@martin-ger I added espconn_tcp_set_max_con(10); here and seems like now i get not so many LmacRxBlk:1 as before.

[TridentTD]

Sorry , I miss type .. I tried by espconn_tcp_set_max_con(10);

https://github.com/martin-ger/esp_wifi_repeater/blob/uMQTT_broker/user/user_main.c#L1842

My scenario.
[Scenario]
192.168.1.1 WiFi Router
192.168.1.2 My computer ( connect to WiFi Router as STATION)
192.168.1.3 ESP8266 with uMQTT broker (ESP8266 connect to Router as STATION)

My computer (192.168.1.2) is contact to ESP8266's broker (192.168.1.3) by MQTT-SPY as mqtt-client ,
However MQTT-SPY on my computer can create mqtt-client to connect to ESP's broker ( recompiled with espconn_tcp_set_max_con(10); ) still only max 5 mqtt-clients.

[svilex]

@TridentTD

bridge uMQTT to outside (on Internet) Broker.

For it to work outside I think you just need to port forward / port map

[TridentTD]

@svilex
Thank you.

[martin-ger]

The max number of TCP connections can be increased with espconn_tcp_set_max_con() but in the repeater there is actually not much RAM left. I moved the project to https://github.com/martin-ger/esp_mqtt without the NAPT functionality (still the uMQTT broker can connect in both networks STA and SoftAP). I managed at least 8 connections there...