Kafka listeners
Charmed Kafka comes with a set of listeners that can be enabled for inter- and intra-cluster communication.
Internal listeners are used for internal traffic and exchange of information between Kafka brokers, whereas external listeners are used for external clients to be optionally enabled based the relations created on particular charm endpoints. Each listener is characterized by a specific port, scope and protocol.
In the following table we summarize the protocols, the port and
the relation that each listener is bound to. Nota that based on whether a certificates
relation is present, one of two mutually exclusive type of listener can be
opened.
Listener name | Driving endpoints | Protocol | Port | Scope |
---|---|---|---|---|
SASL_INTERNAL | cluster |
SASL_PLAINTEXT | 19092 |
internal |
SASL_INTERNAL | cluster + certificates |
SASL_SSL | 19093 |
internal |
SASL_EXTERNAL | kafka-client |
SASL_PLAINTEXT | 9092 |
external |
SASL_EXTERNAL | kafka-client + certificates |
SASL_SSL | 9093 |
external |
SSL_EXTERNAL | trusted-certificate + certificates |
SSL | 9094 |
external |
SSL_EXTERNAL | trusted-ca + certificates |
SSL | 9094 |
external |
Note Since
cluster
is a peer-relation, theSASL_INTERNAL
listener is always enabled.