Mining wont start in Quorum with IBFT using Docker-compose

[alejoloaiza]

Hi, testing using istanbul-tools realized that mining (creation of blocks) in IBFT is not so easy, here I found a scenario where mining wont start after 20 minutes.
Step 1:
Create a docker network with 7 nodes using istanbul with command:
istanbul setup --num 7 --docker-compose --verbose --quorum --save

Step 2:
Now lets start only 4 validators:

docker-compose -f docker-compose.yml up -d eth-stats constellation-0 constellation-1 constellation-2 constellation-3 validator-0 validator-1 validator-2 validator-3

Check that mining is not happening with geth attach http://localhost:8545 it will show at block: 0

Step 3:
Wait 30 minutes, and bring up the 5th node:

docker-compose -f docker-compose.yml up -d constellation-4 validator-4

After waiting another 20 minutes there is not mining going on. I'm still at block 0.

Welcome to the Geth JavaScript console!

instance: Geth/validator-0/v1.7.2-stable/linux-amd64/go1.9
coinbase: 0xa81807268ae6e6f8dddaeac7a75001c764d9d81f
at block: 0 (Sun, 12 Aug 2018 22:00:22 -05)

Thanks a lot.
Regards.