...
- Through a Web service call
- Through a Thrift call
That the default communication protocol of Key Manager is Thrift. If your setup has a cluster of multiple Key Manager nodes that are fronted by a WSO2 ELB instance for load balancing, change the key management protocol from Thrift to WSClient using the <KeyValidatorClientType> element in <APIM_HOME>/repository/conf/api-manager.xml file. Thrift uses TCP load balancing and the ELB does not support it.
...