How to run

1. Build producer and consumer using ./gradlew bootJar
2. docker-compose build
3. docker-compose up

Experiments

Use 10 customer IDs (int wrapped as String):

10 000 messages distributed among 5 consumers:

• consumer #1: 1984 messages
• consumer #2: 2010 messages
• consumer #3: 1996 messages
• consumer #4: 1032 messages
• consumer #5: 2978 messages

Almost uniform distribution, except consumer #4

10 000 messages distributed among 10 consumers:

• consumer #1: 1975 messages
• consumer #2: 0 messages
• consumer #3: 0 messages
• consumer #4: 1989 messages
• consumer #5: 997 messages
• consumer #6: 978 messages
• consumer #7: 0 messages
• consumer #8: 2003 messages
• consumer #9: 1032 messages
• consumer #10: 1026 messages

Looks like 3 consumers out of 10 didn't get any message :(

2> erlang:phash2("1").
129604536
3> erlang:phash2("2").
123894899
4> erlang:phash2("3").
100988150
5> erlang:phash2("4").
45642519
6> erlang:phash2("5").
1444992
7> erlang:phash2("6").
110132422
8> erlang:phash2("7").
96643684
9> erlang:phash2("8").
66522585
10> erlang:phash2("9").
69041393
11> erlang:phash2("10").
128165257

Use 10000 customer IDs (int wrapped as String):

100 000 messages distributed among 10 consumers:

• consumer #1: 9960 messages
• consumer #2: 9662 messages
• consumer #3: 10190 messages
• consumer #4: 10253 messages
• consumer #5: 10036 messages
• consumer #6: 10054 messages
• consumer #7: 9264 messages
• consumer #8: 10155 messages
• consumer #9: 10536 messages
• consumer #10: 9890 messages