Mqtt connection timeout setting

[Stratosphere]

Hi, 

We have observed that in areas of poor lte connectivity, the client_inti() works well but the mqtt_connect() takes a couple of minutes and times out.

I need to change the mqtt connection timeout duration make it 20-30 seconds, since if it does not connect in this duration, for our use-case, it wont connect after either and the firmware can move on.

In decent lte connectivity regions, mqtt_connect returns within a second or less.

Thanks

Noaman

[Håkon Alseth]

Hi,

 

Unfortunately, there is no option to set the timeout at this time, but I will add this as a feature request internally.

 

Kind regards,

Håkon

[Stratosphere]

thank you Haken.

Can you help me add a timeout for http connection requests?

Regards

Noaman

[Håkon Alseth]

Hi,

 

If you enable non-blocking socket operations, the connect() call will return EINPROGRESS until its done.

That can be done like this:

#include <fcntl.h>

    ....
	printk("enable non-blocking connect\n");
	printk("Will return EINPROGRESS (%d) when in progress\n", EINPROGRESS);
	int flags = fcntl(fd, F_GETFL, 0);
	int ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
	int rflags = fcntl(fd, F_GETFL, 0);	
	
	
	printk("connect time: %lld\n", k_uptime_get());
	ret = connect(...)
	printk("connect time: %lld\n", k_uptime_get());
	....

 

I added the logic to the https_client sample in ncs v1.6.0 just so that you can see that the call returns almost immediately when you enable nonblocking socket operation.

Fullscreen nonblock_https_client_ncs_v1.6.0.diff Download

diff --git a/samples/nrf9160/https_client/src/main.c b/samples/nrf9160/https_client/src/main.c
index 509aacb96..18f01a410 100644
--- a/samples/nrf9160/https_client/src/main.c
+++ b/samples/nrf9160/https_client/src/main.c
@@ -5,6 +5,7 @@
  */
 
 #include <string.h>
+#include <fcntl.h>
 #include <zephyr.h>
 #include <stdlib.h>
 #include <net/socket.h>
@@ -202,7 +203,25 @@ void main(void)
 	}
 
 	printk("Connecting to %s\n", "example.com");
+	#if 1
+	printk("enable non-blocking connect\n");
+	printk("Will return EINPROGRESS (%d) when in progress\n", EINPROGRESS);
+	int flags = fcntl(fd, F_GETFL, 0);
+	int ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+	int rflags = fcntl(fd, F_GETFL, 0);	
+	#endif
+	printk("connect time: %lld\n", k_uptime_get());
+
+	/* define this to handle EINPROGRESS scenario */
+	#if ENABLE_NONBLOCK
+	do {
+	#endif
 	err = connect(fd, res->ai_addr, sizeof(struct sockaddr_in));
+	#if ENABLE_NONBLOCK
+	} while (err == EINPROGRESS);
+	#endif
+	
+	printk("connect time: %lld\n", k_uptime_get());
 	if (err) {
 		printk("connect() failed, err: %d\n", errno);
 		goto clean_up;

 

Kind regards,

Håkon

[Stratosphere]

Hi Haken,

I am currently using sdk 1.4.2. should this work on it?

It does not seem to be working for me. here is the console log

RRC mode: Connected
getaddrInfo errno: 0
fcntl nonblocking set: 0. fd : 0, flags: 16384, rflags: 16384
In http timer. http state: 3, currentState: 0, httpQuit: 0
In http timer. http state: 3, currentState: 3, httpQuit: 0
http waiting to connect
http: Connected

"in http timer" is printed every 5 second by a timer callback. "http waiting to connect" is printed from within the do while loop as per code below:

flags = fcntl(fd, F_GETFL, 0);
ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
rflags = fcntl(fd, F_GETFL, 0);	
printk("fcntl nonblocking set: %d. fd : %d, flags: %d, rflags: %d\n", ret, fd, flags, rflags);

fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TLS_1_2);
if (fd == -1) 
{
	if (DEBUG_PRINT_HTTP) printk("Failed to open socket!\n");
	errorReason = ERROR_HTTP_SOCKET_FAILED;
	goto clean_up;
}

httpState = 2;
/* Setup TLS socket options */
err = httpTlsSetup(fd);
if (err) 
{
	errorReason = ERROR_HTTP_SECURECLIENT_INIT_FAIL;
	goto clean_up;
}

httpState = 3;

//Connect
{
	waitingToConnect = 0;
	do 
	{
		err = connect(fd, res->ai_addr , sizeof(struct sockaddr_in));
		k_sleep(100);
		waitingToConnect++;
		printk("http waiting to connect\n");
	} while ((err == EINPROGRESS) && (waitingToConnect <300));

	if (err || waitingToConnect >=300)
	{
		if (DEBUG_PRINT_HTTP) printk("connect() failed, time: %d, err: %d\n", waitingToConnect, errno);
		if (errno == 23)
			sys_reboot(0);

		errorReason = ERROR_HTTP_CONNECT_FAILED;
		goto clean_up;
	}
	if (DEBUG_PRINT_HTTP) printk("http: Connected\n");
}

"http waiting to connect" should be printed every 100ms if connect() is non-blocking. so it seems that connect() is still using a blocking call.

[Håkon Alseth]

Hi,

 

My apologies for the late reply.

 

Stratosphere said:

I am currently using sdk 1.4.2. should this work on it?

This functionality was not added until more recent. Is it technically possible for you to use a newer ncs version?

 

Kind regards,

Håkon