In this scenario we have a 4 nodes EAP cluster where a clustered HA Singleton Service is intalled;

We observed an increased number of server side erroros and a corresponding increase in client fail rate from about 4.5% to 6.8% when using about 100 clients;

Below we report the exceptions registered both onthe server and the client side for EAP 7.2 and EAP 7.3 (note client side errors increased):

7.2

client:

javax.ejb.ConcurrentAccessTimeoutException: 812

server:

java.util.concurrent.CancellationException

node1: 34
node2: 34
node3: 30
node4: 3

javax.ejb.ConcurrentAccessTimeoutException

node1: 348
node2: 460
node3: 0
node4: 816

7.3

client:

javax.ejb.ConcurrentAccessTimeoutException: 1192

server:

java.util.concurrent.CancellationException

node1: 32
node2: 22
node3: 4
node4: 7

javax.ejb.ConcurrentAccessTimeoutException

node1: 448
node2: 396
node3: 802
node4: 738

java.util.concurrent.CompletionException

node1: 3
node2: 7
node3: 2
node4: 5

Complete logs and test app attached;