Client has exceeded timeout, disconnecting.

[MichMich]

Ok, I'm starting to bang my head against the wall here.

I'm running a Mosquitto (1.4.7) MQTT server on my CentOS Web Server. Using MQTT.js I created a small node script that connects to this server.

When I run this Node script on my web server, it connects, but every few 10-30 seconds, it disconnects and reconnects. The Mosquito log states the following:

 1455282675: Client mqttjs_057aaa0a has exceeded timeout, disconnecting.

The weird thing is, this only is the case when I run this node script on the same server as my Mosquitto server. If I run the script from an other machine (for example my Mac), it works fine and remains connected without any issue.

I already tried disabling the Firewall on my Web Server but without any succes.

Any idea what could cause this weird behavior? Where I should start looking?

Thanks in advance!

[MichMich]

I think I got a bit further: when I connect to the mosquitto test server, it has the same problems.
So:

• running the node.js script on my mac = no problem, stable connection
• running the node.js script on my centos web server = disconnections, unstable connection.

I'll try to figure out what the issue is on the CentOs server. Any suggestion is welcome.

[MichMich]

I figured out I can solve this by occasionally publishing a message. Only subscribing causes the issue. It does feel like a workaround, though.

[mcollina]

How long is your keepalive? It should really be measured in minutes.

[MichMich]

I did not change the default config.

[mcollina]

Try increasing that.

[MichMich]

The default keepalive is 10 seconds. Would you suggest lowering it? To 5 seconds?

[mcollina]

Nope, increasing it to 60+.
Il giorno dom 14 feb 2016 alle 16:34 Michael Teeuw notifications@github.com
ha scritto:

The default keepalive is 10 seconds. Would you suggest lowering it? To 5
seconds?

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Reply to this email directly or view it on GitHub
#381 (comment).

[MichMich]

Ah, I see! I was under the assumption, the keepalive property was the number of seconds between every keep alive ping. I now understand it's the max number of seconds it can go without any contact.
Increasing the number did improve the connection a bit. But as you can guess, the error still occurs after 60+ seconds. - Is there a maximum number of seconds I can use?

[hakanernam]

Actually, the maximum amount of time without a contact(Control packet) without a forced server disconnect is 1.5 times that. [MQTT3.1.1 - 3.1.2.10 Keep Alive]. Max keep-alive value is 65535 seconds as the value is a 16-bit word. But I understand from the docs MQTT.js client already should handle ping requests:

https://github.com/mqttjs/MQTT.js#mqttclientstreambuilder-options

[mcollina]

Which version of Mosquitto do you have on your server, and which one do you have locally?
Maybe the two versions behave differently.

I think this is due to #355 cc @4rzael .

[mcollina]

Can any other reproduce this problem? I fear it might be something in the server config.

[hakanernam]

He stated that he connected to mosquito test server from separate machines, so I believe ping requests somehow do not go out when running the script on his web server as they should.

[MichMich]

Exactly. It's not based in the server I connect to, but based on the server I'm running my script on. It seems it doesn't keep the connection alive (pings).

[hakanernam]

I suspect a race condition or maybe a permission issue could be causing _setupPingTimer function not being called or the interval not being set.

I would advise copying the repository to same directory as your script, putting some log statements in that function and _checkPing to see if they are indeed called.

[MichMich]

Will do! I'll report back as soon as I find a cause or solution.