The layout of subsystems has changed in Infinispan 8, and this has caused a regression in the server CLI (tracking it with https://issues.jboss.org/browse/ISPN-5952)

You can however get to the containers and caches as follows (you can use tab completion at any stage):

Standalone mode

$ ./bin/ispn-cli.sh
You are disconnected at the moment. Type 'connect' to connect to the server or 'help' for the list of supported commands.
[disconnected /] connect
[standalone@localhost:9990 /] cd subsystem=datagrid-infinispan/cache-container=local
[standalone@localhost:9990 cache-container=local] cd local-cache=namedCache
[standalone@localhost:9990 local-cache=namedCache]

Domain mode

$ ./bin/ispn-cli.sh
You are disconnected at the moment. Type 'connect' to connect to the server or 'help' for the list of supported commands.
[disconnected /] connect
[domain@localhost:9990 /] cd profile=clustered/subsystem=datagrid-infinispan/cache-container=clustered
[domain@localhost:9990 cache-container=clustered] cd distributed-cache=namedCache
[domain@localhost:9990 distributed-cache=namedCache]

Note that in domain mode the above will take you to the profile definition of your cache. To get information about statistics and such, you need to go to a specific node:

$ ./bin/ispn-cli.sh
You are disconnected at the moment. Type 'connect' to connect to the server or 'help' for the list of supported commands.
[disconnected /] connect
[domain@localhost:9990 /] cd host=master/server=server-one
[domain@localhost:9990 server=server-one] cd subsystem=datagrid-infinispan/cache-container=clustered/distributed-cache=namedCache
[domain@localhost:9990 distributed-cache=namedCache] ls
backup                                  cache-rebalancing-status=COMPLETE        clusterwide-misses=0                    configuration=namedCache                remove-hits=0                           
transaction                              cache-status=RUNNING                    clusterwide-number-of-entries=0          evictions=0                              remove-misses=0                         
activations=0                            clusterwide-activations=0                clusterwide-number-of-locks-available=0  hit-ratio=0.0                            replication-count=2                     
average-read-time=0                      clusterwide-average-read-time=0          clusterwide-number-of-locks-held=0      hits=0                                  replication-failures=0                 
average-remove-time=0                    clusterwide-average-remove-time=0        clusterwide-passivations=0              invalidations=0                          rollbacks=0                             
average-replication-time=11              clusterwide-average-write-time=0        clusterwide-read-write-ratio=0.0        misses=0                                stores=0                               
average-write-time=0                    clusterwide-cache-loader-loads=0        clusterwide-remove-hits=0                number-of-entries=0                      success-ratio=1.0                       
cache-availability=AVAILABLE            clusterwide-cache-loader-misses=0        clusterwide-remove-misses=0              number-of-locks-available=0              time-since-reset=14                     
cache-loader-loads=0                    clusterwide-cache-loader-stores=0        clusterwide-stores=0                    number-of-locks-held=0                  time-since-start=14                     
cache-loader-misses=0                    clusterwide-evictions=0                  clusterwide-time-since-reset=14          passivations=0                          version=8.1.0-SNAPSHOT                 
cache-loader-stores=0                    clusterwide-hit-ratio=0.0                clusterwide-time-since-start=14          prepares=0                             
cache-name=namedCache                    clusterwide-hits=0                      commits=0                                read-write-ratio=0.0                   
cache-rebalance=true                    clusterwide-invalidations=0              concurrency-level=1000                  rebalancing=true