Mqtt disconnecting when another publish - c

Question

I have 2 gateways (OS:yocto embedded linux ).Which send and receive commands from a cloud application.When i run mqtt application in gateway 1 alone, it is able to send and receive commands from cloud application.And when i run gatway1 and gateway 2 together, they are able to send commands to cloud application but when cloud send a command to any of the gateway the other one is disconnecting.
Im using paho-mqtt c library version 3.1
i tried different client ID specific TOPIC but none of them worked,please give me some help .
here is my MQTT application.
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "MQTTAsync.h"
#if !defined(WIN32)
#include <unistd.h>
#else
#include <windows.h>
#endif
#define ADDRESS "test.mosquitto.org:1883"
#define CLIENTID "ExampleClientPub1" //client id is UNIQUE
#define TOPIC_SUB "pubTopic" /*2 gateways subscribed to this topic and cloud app publish to this topic */
#define TOPIC_PUB "MQTT Examples" /*gateway send message to this topic and cloud app subscribe to this topic*/
#define PAYLOAD "******from app2!******" /* sample payload*/
#define QOS 1
#define TIMEOUT 10000L
volatile MQTTAsync_token deliveredtoken;
int finished = 0;
MQTTAsync client;
int disc_finished = 0;
int subscribed = 0;
void connlost(void *context, char *cause)
{
MQTTAsync_connectOptions conn_opts = MQTTAsync_connectOptions_initializer;
int rc;
printf("\nConnection lost\n");
printf(" cause: %s\n", cause);
printf("Reconnecting\n");
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
if ((rc = MQTTAsync_connect(client, &conn_opts)) != MQTTASYNC_SUCCESS)
{
printf("Failed to start connect, return code %d\n", rc);
finished = 1;
}
}
void onDisconnect(void* context, MQTTAsync_successData* response)
{
printf("Successful disconnection\n");
finished = 1;
}
void onSend(void* context, MQTTAsync_successData* response)
{
// MQTTAsync_disconnectOptions opts = MQTTAsync_disconnectOptions_initializer;
int rc;
printf("Message with token value %d delivery confirmed\n", response->token);
// opts.onSuccess = onDisconnect;
// opts.context = client;
// if ((rc = MQTTAsync_disconnect(client, &opts)) != MQTTASYNC_SUCCESS)
// {
// printf("Failed to start sendMessage, return code %d\n", rc);
// exit(EXIT_FAILURE);
// }
}
void onConnectFailure(void* context, MQTTAsync_failureData* response)
{
printf("Connect failed, rc %d\n", response ? response->code : 0);
finished = 1;
}
void transfer() /*function usesd for publishing*/
{
static int i=1;
printf("\n................................Transmitt %d................................\n",i++);
MQTTAsync_responseOptions opts = MQTTAsync_responseOptions_initializer;
MQTTAsync_message pubmsg = MQTTAsync_message_initializer;
int rc;
printf("Successful connection\n");
opts.onSuccess = onSend;
opts.context = client;
pubmsg.payload = PAYLOAD;
pubmsg.payloadlen = strlen(PAYLOAD);
pubmsg.qos = QOS;
pubmsg.retained = 0;
deliveredtoken = 0;
if ((rc = MQTTAsync_sendMessage(client, TOPIC_PUB, &pubmsg, &opts)) != MQTTASYNC_SUCCESS)
{
printf("Failed to start sendMessage, return code %d\n", rc);
exit(EXIT_FAILURE);
}
}
/************subscribe****************/
void onSubscribe(void* context, MQTTAsync_successData* response)
{
printf("Subscribe succeeded\n");
subscribed = 1;
}
void onSubscribeFailure(void* context, MQTTAsync_failureData* response)
{
printf("Subscribe failed, rc %d\n", response ? response->code : 0);
finished = 1;
}
void onConnect(void* context, MQTTAsync_successData* response)
{
MQTTAsync client = (MQTTAsync)context;
MQTTAsync_responseOptions opts = MQTTAsync_responseOptions_initializer;
MQTTAsync_message pubmsg = MQTTAsync_message_initializer;
int rc;
printf("Successful connection\n");
printf("Subscribing to topic %s\nfor client %s using QoS%d\n\n"
"Press Q<Enter> to quit\n\n", TOPIC_SUB, CLIENTID, QOS);
opts.onSuccess = onSubscribe;
opts.onFailure = onSubscribeFailure;
opts.context = client;
deliveredtoken = 0;
if ((rc = MQTTAsync_subscribe(client, TOPIC_SUB, QOS, &opts)) != MQTTASYNC_SUCCESS)
{
printf("Failed to start subscribe, return code %d\n", rc);
exit(EXIT_FAILURE);
}
}
int msgarrvd(void *context, char *topicName, int topicLen, MQTTAsync_message *message)
{
int i;
char* payloadptr;
printf("Message arrived\n");
printf(" topic: %s\n", topicName);
printf(" message: ");
payloadptr = message->payload;
for(i=0; i<message->payloadlen; i++)
{
putchar(*payloadptr++);
}
putchar('\n');
MQTTAsync_freeMessage(&message);
MQTTAsync_free(topicName);
return 1;
}
int main ()
{
MQTTAsync_connectOptions conn_opts = MQTTAsync_connectOptions_initializer;
MQTTAsync_message pubmsg = MQTTAsync_message_initializer;
MQTTAsync_token token;
int rc;
MQTTAsync_create(&client, ADDRESS, CLIENTID, MQTTCLIENT_PERSISTENCE_NONE, NULL);
MQTTAsync_setCallbacks(client, NULL, connlost, msgarrvd, NULL);
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
conn_opts.onSuccess = onConnect;
conn_opts.onFailure = onConnectFailure;
conn_opts.context = client;
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
conn_opts.onSuccess = onConnect;
conn_opts.onFailure = onConnectFailure;
conn_opts.context = client;
if ((rc = MQTTAsync_connect(client, &conn_opts)) != MQTTASYNC_SUCCESS)
{
printf("Failed to start connect, return code %d\n", rc);
exit(EXIT_FAILURE);
}
while(!subscribed)
#if defined(WIN32)
Sleep(100);
#else
usleep(10000L);
#endif
while(1)
{
sleep(1);
transfer();
sleep(2);
}
}