I added a GetTwitter processor in Nifi and it started giving me below errors.
2017-03-19 00:40:53,125 ERROR [Timer-Driven Process Thread-7] o.a.nifi.processors.twitter.GetTwitter GetTwitter[id=e3bea5be-015a-1000-d6ab-b8ee578960b5] Received error CONNECTION_ERROR: Failed to establish connection properly. Will attempt to reconnect
ERROR [Timer-Driven Process Thread-6] o.a.nifi.processors.twitter.GetTwitter GetTwitter[id=e3bea5be-015a-1000-d6ab-b8ee578960b5] Received error CONNECTION_ERROR: java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty. Will attempt to reconnect.
I checked nifi-app.log and it has the same error.
Note: When I'm running it on my local windows 10 laptop using localhost:9090/nifi/ it is working fine but when I'm running it on HDP Sandbox of Linux environment using link <hostip>:8080/nifi then it is giving me above error.
This might be because your Linux sandbox does not have current/any CA public certificates with which to authenticate the Twitter server certificate. You can find instructions for updating the default CA certificates for CentOS (the base OS of the sandbox) online (basically just
$ yum install ca-certificates && update-ca-trust force-enable), and more information on adding custom CA certs if necessary