Basic example fails if a room uses more than one Erizo

[nvazquezg]

Description

If Licode is configured in a way that allows a room to use more than one Erizo, the subscription to remote streams fails most of the time.

Steps to reproduce the issue:

1. Configure licode to allow rooms to use more than one Erizo. For example, in licode_config.js:

config.erizoController.maxErizosUsedByRoom = 100;  // default value: 100
config.erizoAgent.maxProcesses    = 2; // default value: 1

2. Start Licode and Basic Example:

$ ./scripts/initLicode.sh
$ ./scripts/initBasicExample.sh

3. Connect to Licode Basic Example using two chrome browser windows with a webcam available. By default: http://localhost:3001/

Describe the results you received:
The first browser only shows one video.
The second browser shows two videos (sometimes one).

Describe the results you expected:
The first browser shows two videos.
The second browser must show two videos.

Additional information you deem important (e.g. issue happens only occasionally):
Issue happens every time.
When it fails, a message is shown this message in the console:

WARNING:  processAnswer discarding old sdp, sessionVersion: 0, latestSessionVersion: 0

If we change maxProcesses to its default value (1) or maxErizosUsedByRoom to 1 it works every time.
In versión pre-v7.8 this use case worked.

Licode commit/release where the issue is happening
pre-v7.11: 245fb64

Additional environment details (Local, AWS, Docker, etc.):
Same behaviour in Local and using official docker image lynckia/licode:245fb64.
Chrome 75.

[ashar02]

@jcague I also tested the latest code till commit #1429 a moment ago. When I changed the default value of either config.erizoAgent.maxProcesses or config.erizoAgent.prerunProcesses I also started facing same problem as mentioned in this issue. Most of the time subscription failed. Can you please look into this?

[ashar02]

@lodoyun can you please look into this issue?

[jcague]

@ashar02 I think I found the issue you are having with the latest versions, can you test it with #1439 please?

[ashar02]

Okay let me test and get back to you soon!!

[ashar02]

Yes fixed on my environment as well. Great Job!!