Queued sessions inconsistent behaviour Grid V4 vs Grid V3

🐛 Bug Report

I have 2 grids:

• 3.141.59-20210105
• 4.0.0-beta-1-prerelease-20210114

with 1 Chrome node. You can use the following docker compose file to spin up the same environment docker-compose.yml.zip

I am sending 2 Chrome tests in parallel but experiencing different behaviour between Grid v3 vs Grid v4 nunitProject.zip

Selenium 3 Grid behaviour

• Because there is just one node, 1 test is put into a queue waiting for the first one to be finished then it is executed successfully

Logs: selenium3GridLogs.txt

Selenium 4 Grid behaviour

• First test is sent to the grid and executed properly
• Second test is running and trying to create session, eventually times out.

After the first test is finished I can see graphql response saying there is available slot, yet it is not being assigned to my second test { "data": { "grid": { "nodes": [ { "id": "bb800483-fb81-4fea-849b-62ec4a23cb7b", "uri": "http://172.19.0.3:5555", "status": "UP", "sessions": [], "maxSession": 1, "capabilities": "[\n {\n \"slots\": 1,\n \"browserName\": \"chrome\"\n }\n]" } ], "uri": "http://172.19.0.2:4444", "totalSlots": 1, "usedSlots": 0, "sessionCount": 0 } } }

• Furthermore there is no indication in Grid UI that node would be in use and no information about queued session either

Logs: seleniumGrid4Logs.txt

[mcopjan]

Hi @pujagani, I did more testing on this with the latest prerelease 4.0.0-beta-1-prerelease-20210128, restarted the environment multiple times and I am not seeing the reported behaviour any more. I think we can close this ticket. Thanks again for your time you spend with your investigation. concurrentSessionsOk.log

[mcopjan]

thanks @pujagani, one more thing I will try is to run grid in full mode, make sure all components are ready, then run the same tests and if I experience the same problem I will collect logs from all components and report back.