Diagnosing a kJams Cue Connection Issue At Popular Venue

[jamespedid]

Hello kJams Board,

I am trying to diagnose an issue with kJams Cue where it fails to connect to the server. Note that I'm working with the operator kind of as a tech support/fan of the karaoke service they provide and want to give back and fix this issue.

The symptoms as best as I can describe the issue:

When opening the kJams app, it says "Connected to Singer" or something along those lines. It then fails to show any list. Eventually this changes to "Lost connection to server" and it appears to be in a reconnect loop as far as I can tell. It generally doesn't reconnect at all if this happens. If I restart the kJams Cue, it appears to be random as to when it accepts a connection and actually allows a user to load the app further.

This issue appears to happen even at low volumes of users trying to access the app. Additionally, once a person is in, it seems like they're in, and have no trouble reconnecting for the night. On subsequent nights, it's almost a lottery as to who can use the app from their phone.
 
To my knowledge, the operator runs this operation on a MacOSX. (Not sure if 64 bit or not, but I'm assuming so? I can clarify if that could be an issue.)

A couple of thoughts I had was to examine some of the server source code that is shipped with the product. One thing I'm on the eye out for is a connection limit. I suspect that perhaps there could be some settings at the MacOSX level, such as the ulimit command, that might be able to help, and this will probably be the first thing I tell the operator to try. I'm wondering if anyone else has had this issue, and what they did to correct it.

[dave]

When opening the kJams app

Do you mean the Cue app?

it says "Connected to Singer" or something along those lines

maybe take a screen shot, or quote the exact words?

fails to show any list

would that be the list of singers? just making sure...

this changes to "Lost connection to server"

could be the venue's WIFI is interfering? have you tried bringing your own wifi router? you'd have to wire it into the Venue router (literally with a wire), so that YOUR router could get to the rest of the internet, but with your own router (eg: a nice Eero router), you could eliminate the variable of using someone else's router over which you have no control. Have your computer on your router, and have all the Cue users on your router.

examine some of the server source code that is shipped with the product

the web code is available by doing this: run kJams, then in the help menu pick: reveal preferences. in there you'll see "server"
the C++ back end however i can't share.

I'm on the eye out for is a connection limit

there is no connection limit built into kJams that i'm aware of

[dave]

[jamespedid]

Hello!

Yes, I am using the Cue app. I have included three screenshots to explain what is happening. There are three pictures: 1.) Connected to Karaoke Singers, 2.) The Karaoke Singers List, and 3.) Lost Connection to Server.

The desired flow is 1.) Connected to Karaoke Singers, 2.) The Karaoke Singers List.

The failure flow is 1.) Connected to Karaoke Singers, 3.) Lost Connection to Server (repeating after a regular reconnect interval).

When the desired flow is met, no complaint. So the rest of this message is going to be about the failure flow.

When going to this venue, it seems at random as to when we are in the failure flow. Sometimes it's in the failure flow all night. Sometimes it's in the failure flow and then transitions eventually to the desired flow. Sometimes it's in the desired flow and transitions to the failure flow. And sometimes it always works. All permutations happen.

Additionally, it doesn't seem like the volume of people at the venue matters. Normally this is a pretty crowded spot, so at first I thought it might be due to WIFI access points not being able to handle the volume, or due to the software itself being connection limited.

Last night though I was at the venue, and the volume of people there was not high, especially early in the night. And I found myself in the permutation where it would never connect to the app. So I dug in a bit more and found out that it appears the webserver itself was not running, as the <networkname>.local was not resolving to the webserver. Additionally, using a bonjour browser, there was no ip addresses that were detected. (The tool itself kept scanning and could not find a server.)

So this leads me to two ideas: one is that the users of the software at the venue are unknowingly disabling the server, or that the server is somehow crashing or not starting up properly every time, or simply isn't being responsive to network traffic at the time.

I'm wondering if you have any thoughts on what might cause this behavior.

[dave]

have you tried using your own WIFI router?

[dave]

that must have been it?