Question

我已经建立了一个用于MQTT通信的Mosquitto代理，但我甚至无法开箱即用。连接并等待一段时间后服务器重置客户端连接并显示 'Socket error on client .. , disconnecting.'

我几乎排除了客户端的错误，因为使用两个不同的（MQTT.fx和mqtt-spy）客户端软件时错误仍然存在。

Connection-timeout: 30
Keep-alive interval: 30

Mosquitto运行最新版本（mosquitto版本1.4.2）和库存配置。

我执行以下操作：

连接
发送测试讯息＆＃39;测试＆＃39;关于主题＆＃39; test＆＃39;
等待
套接字错误

修改

贯穿代码

static void loop_handle_reads_writes(struct mosquitto_db *db, struct pollfd *pollfds)
{
    [...]
    if(pollfds[context->pollfd_index].revents & POLLIN){
        if(_mosquitto_packet_read(db, context)){
            do_disconnect(db, context); <-- Line that causes disconnection
            continue;
        }
    }
}

[...]
void do_disconnect(struct mosquitto_db *db, struct mosquitto *context)
{
    char *id;

    if(context->state == mosq_cs_disconnected){
        return;
    }
    [...]
    {
        if(db->config->connection_messages == true){
            if(context->id){
                id = context->id;
            }else{
                id = "<unknown>";
            }
            if(context->state != mosq_cs_disconnecting){
                _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Socket error on client %s, disconnecting.", id);
            }else{
                _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Client %s disconnected.", id);
            }
        }
        mqtt3_context_disconnect(db, context);
         [...]
        if(context->clean_session){
            mosquitto__add_context_to_disused(db, context);
            if(context->id){
                HASH_DELETE(hh_id, db->contexts_by_id, context);
                _mosquitto_free(context->id);
                context->id = NULL;
            }
        }
        context->state = mosq_cs_disconnected;
    }
}

控制台日志：

1433171947: New connection from 192.168.2.5 on port 1883.
1433171947: New client connected from 192.168.2.5 as testuser (c1, k30, u'testuser').
1433171947: Sending CONNACK to testuser (0, 0)
1433171954: Received PUBLISH from testuser (d0, q1, r1, m1, 'test', ... (4 bytes))
1433171954: Sending PUBACK to testuser (Mid: 1)
1433171984: Received PINGREQ from testuser
1433171984: Sending PINGRESP to testuser
1433172003: Socket error on client testuser, disconnecting.

以下是交换的13帧的数据包捕获和连接重置导致套接字错误。

服务器（192.168.2.15）捕获脚本：

No.     Time           Source                Destination           Protocol Length Info
    129 14.587072000   192.168.2.5           192.168.2.15          TCP      62     55176 > ibm-mqisdp [SYN] Seq=0 Win=8192 Len=0 MSS=1460 SACK_PERM=1

Frame 129: 62 bytes on wire (496 bits), 62 bytes captured (496 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 0, Len: 0

No.     Time           Source                Destination           Protocol Length Info
    131 14.587250000   192.168.2.5           192.168.2.15          TCP      60     55176 > ibm-mqisdp [ACK] Seq=1 Ack=1 Win=17424 Len=0

Frame 131: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 1, Ack: 1, Len: 0

No.     Time           Source                Destination           Protocol Length Info
    132 14.589586000   192.168.2.5           192.168.2.15          TCP      92     55176 > ibm-mqisdp [PSH, ACK] Seq=1 Ack=1 Win=17424 Len=38

Frame 132: 92 bytes on wire (736 bits), 92 bytes captured (736 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 1, Ack: 1, Len: 38
Data (38 bytes)

0000  10 24 00 04 4d 51 54 54 04 c2 00 1e 00 08 74 65   .$..MQTT......te
0010  73 74 75 73 65 72 00 08 74 65 73 74 75 73 65 72   stuser..testuser
0020  00 04 6d 61 72 79                                 ..mary

No.     Time           Source                Destination           Protocol Length Info
    135 14.590183000   192.168.2.5           192.168.2.15          TCP      60     55176 > ibm-mqisdp [ACK] Seq=39 Ack=5 Win=17420 Len=0

Frame 135: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 39, Ack: 5, Len: 0

No.     Time           Source                Destination           Protocol Length Info
    144 21.534467000   192.168.2.5           192.168.2.15          TCP      68     55176 > ibm-mqisdp [PSH, ACK] Seq=39 Ack=5 Win=17420 Len=14

Frame 144: 68 bytes on wire (544 bits), 68 bytes captured (544 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 39, Ack: 5, Len: 14
Data (14 bytes)

0000  33 0c 00 04 74 65 73 74 00 01 74 65 73 74         3...test..test

No.     Time           Source                Destination           Protocol Length Info
    146 21.534941000   192.168.2.5           192.168.2.15          TCP      60     55176 > ibm-mqisdp [ACK] Seq=53 Ack=9 Win=17416 Len=0

Frame 146: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 53, Ack: 9, Len: 0

No.     Time           Source                Destination           Protocol Length Info
    184 51.556401000   192.168.2.5           192.168.2.15          TCP      60     55176 > ibm-mqisdp [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 184: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
    187 51.850874000   192.168.2.5           192.168.2.15          TCP      60     [TCP Retransmission] 55176 > ibm-mqisdp [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 187: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
    190 52.452535000   192.168.2.5           192.168.2.15          TCP      60     [TCP Retransmission] 55176 > ibm-mqisdp [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 190: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
    197 53.655674000   192.168.2.5           192.168.2.15          TCP      60     [TCP Retransmission] 55176 > ibm-mqisdp [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 197: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
    201 56.056945000   192.168.2.5           192.168.2.15          TCP      60     [TCP Retransmission] 55176 > ibm-mqisdp [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 201: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
    213 60.854141000   192.168.2.5           192.168.2.15          TCP      60     [TCP Retransmission] 55176 > ibm-mqisdp [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 213: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
    233 70.449632000   192.168.2.5           192.168.2.15          TCP      60     55176 > ibm-mqisdp [RST, ACK] Seq=55 Ack=9 Win=0 Len=0

Frame 233: 60 bytes on wire (480 bits), 60 bytes captured (480 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: ibm-mqisdp (1883), Seq: 55, Ack: 9, Len: 0

客户端（192.168.2.5）捕获脚本：

No.     Time           Source                Destination           Protocol Length Info
    174 5.754193000    192.168.2.5           192.168.2.15          TCP      62     55176→1883 [SYN] Seq=0 Win=8192 Len=0 MSS=1460 SACK_PERM=1

Frame 174: 62 bytes on wire (496 bits), 62 bytes captured (496 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 0, Len: 0

No.     Time           Source                Destination           Protocol Length Info
    176 5.754376000    192.168.2.5           192.168.2.15          TCP      54     55176→1883 [ACK] Seq=1 Ack=1 Win=17424 Len=0

Frame 176: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 1, Ack: 1, Len: 0

No.     Time           Source                Destination           Protocol Length Info
    177 5.756658000    192.168.2.5           192.168.2.15          TCP      92     55176→1883 [PSH, ACK] Seq=1 Ack=1 Win=17424 Len=38

Frame 177: 92 bytes on wire (736 bits), 92 bytes captured (736 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 1, Ack: 1, Len: 38
Data (38 bytes)

0000  10 24 00 04 4d 51 54 54 04 c2 00 1e 00 08 74 65   .$..MQTT......te
0010  73 74 75 73 65 72 00 08 74 65 73 74 75 73 65 72   stuser..testuser
0020  00 04 6d 61 72 79                                 ..mary

No.     Time           Source                Destination           Protocol Length Info
    180 5.757101000    192.168.2.5           192.168.2.15          TCP      54     55176→1883 [ACK] Seq=39 Ack=5 Win=17420 Len=0

Frame 180: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 39, Ack: 5, Len: 0

No.     Time           Source                Destination           Protocol Length Info
    393 12.701517000   192.168.2.5           192.168.2.15          TCP      68     55176→1883 [PSH, ACK] Seq=39 Ack=5 Win=17420 Len=14

Frame 393: 68 bytes on wire (544 bits), 68 bytes captured (544 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 39, Ack: 5, Len: 14
Data (14 bytes)

0000  33 0c 00 04 74 65 73 74 00 01 74 65 73 74         3...test..test

No.     Time           Source                Destination           Protocol Length Info
    395 12.701938000   192.168.2.5           192.168.2.15          TCP      54     55176→1883 [ACK] Seq=53 Ack=9 Win=17416 Len=0

Frame 395: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 53, Ack: 9, Len: 0

No.     Time           Source                Destination           Protocol Length Info
   1192 42.723471000   192.168.2.5           192.168.2.15          TCP      56     55176→1883 [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 1192: 56 bytes on wire (448 bits), 56 bytes captured (448 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
   1205 43.017917000   192.168.2.5           192.168.2.15          TCP      56     [TCP Retransmission] 55176→1883 [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 1205: 56 bytes on wire (448 bits), 56 bytes captured (448 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
   1213 43.619506000   192.168.2.5           192.168.2.15          TCP      56     [TCP Retransmission] 55176→1883 [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 1213: 56 bytes on wire (448 bits), 56 bytes captured (448 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
   1236 44.822621000   192.168.2.5           192.168.2.15          TCP      56     [TCP Retransmission] 55176→1883 [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 1236: 56 bytes on wire (448 bits), 56 bytes captured (448 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
   1273 47.224018000   192.168.2.5           192.168.2.15          TCP      56     [TCP Retransmission] 55176→1883 [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 1273: 56 bytes on wire (448 bits), 56 bytes captured (448 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
   1462 52.021241000   192.168.2.5           192.168.2.15          TCP      56     [TCP Retransmission] 55176→1883 [PSH, ACK] Seq=53 Ack=9 Win=17416 Len=2

Frame 1462: 56 bytes on wire (448 bits), 56 bytes captured (448 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 53, Ack: 9, Len: 2
Data (2 bytes)

0000  c0 00                                             ..

No.     Time           Source                Destination           Protocol Length Info
   1713 61.616726000   192.168.2.5           192.168.2.15          TCP      54     55176→1883 [RST, ACK] Seq=55 Ack=9 Win=0 Len=0

Frame 1713: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on interface 0
Ethernet II, Src: Cisco-Li_21:62:a7 (00:1e:e5:21:62:a7), Dst: NX_6a:d6:31 (00:0c:29:6a:d6:31)
Internet Protocol Version 4, Src: 192.168.2.5 (192.168.2.5), Dst: 192.168.2.15 (192.168.2.15)
Transmission Control Protocol, Src Port: 55176 (55176), Dst Port: 1883 (1883), Seq: 55, Ack: 9, Len: 0

Answer 1

_mosquitto_packet_read()失败的最可能原因是远程端关闭了连接，因此无法读取。如果do_disconnect()到达你提到的那一点，那么从代理的角度来看，套接字基本上是开放的。

我刚尝试使用下面的客户端代码重现此问题（您需要安装Paho Python，pip install paho-mqtt）。

import paho.mqtt.client as paho

mqtt = paho.Client(client_id="testuser", clean_session=True)
mqtt.username_pw_set("testuser", "password")
mqtt.connect("localhost", 1883, 30)
mqtt.publish("test", "test", qos=1, retain=True)
mqtt.loop_forever()

我从经纪人那里得到的日志是：

1433245884: New connection from ::1 on port 1883.
1433245884: New client connected from ::1 as testuser (c1, k30, u'testuser').
1433245884: Sending CONNACK to testuser (0, 0)
1433245884: Received PUBLISH from testuser (d0, q1, r1, m1, 'test', ... (4 bytes))
1433245884: Sending PUBACK to testuser (Mid: 1)
1433245915: Received PINGREQ from testuser
1433245915: Sending PINGRESP to testuser
1433245945: Received PINGREQ from testuser
1433245945: Sending PINGRESP to testuser
1433245975: Received PINGREQ from testuser
1433245975: Sending PINGRESP to testuser
...

你可以在你的系统上试试这个吗？

Answer 2

在从蚊子到EMQ代理的网桥配置中，我们遇到了此错误。我们有两个网桥，其中一个在QoS 0上，并且过去运行良好。 QoS 2上的一个出现了问题。以下是可以帮助您的观察和步骤：

启用mosquitto的完整日志记录

这是通过在mosquitto配置中设置log_type all属性来实现的。根据您的Linux发行版，在/var/log/mosquitto/mosquitto.log或'/ var / log / messages`上查找错误。

我们发现了什么

蚊子队列中的消息需要发布到EMQ，而EMQ也有消息队列的消息发布到mosquitto。建立连接后，代理将忙于发送数据包，而蚊子通常会错过PINGREQ在配置的时间发送的keepalive_interval。

在使用命令sudo emqttd_ctl listeners检查客户端终止的EMQ原因时，可能会发现超时是问题所在。因此，我们使用mqtt.client.idle_timeout增加了EMQ的超时时间。

该问题已在第二天再次发生的当天修复。在检查EMQ上的日志时，超时是终止的原因，并且在指定时间内没有mosquitto发送PINGREQ。我们怀疑带宽和一口气推送许多大小合适的消息被认为是终止的原因。我们决定通过将飞行消息计数设置为1来设置mosquitto和EMQ一次发送一条消息。这样可以使连接稳定并传递邮件。

建议您在mosquitto上增加retry_interval，在EMQ上增加mqtt.session.retry_interval，以防您在QoS 1或2上发送了大型消息。另外，EMQ上的mqtt.session.await_rel_timeout很重要在这种情况下的配置。 mqtt.client.max_publish_rate是另一个值得研究的东西。

连接约一分钟后{MQHT套接字错误

2 个答案:

启用mosquitto的完整日志记录

我们发现了什么