Hi Brayn, Thank you for your answer.
In the first error, it looks like maybe you had PutSyslog configured for TLS/SSL, but were sending to a port that was not listening for TLS/SSL, but regular TCP. --> I suspected same thing therefore I tried same process (with Java JRE 1.8.0_241 (64 Bit)) through Logstash 7.3.1 with secure (TLS) configuration and it run. In the second error, it means the truststore in the SSL Context Service in NiFi, does not trust the certificate presented by the syslog server. --> I thought same thing and I added my certificate, root certificate, intermediate certificate (I mean all of them) to keystore, truststore and java cacert. I mean, I added all the certificates to almost all stores. I tried 2 different version of Java with same certificate configuration (stores, cacert etc) to make sure there was no problem with Java Java 8 Error: javax.net.ssl.SSLException: Inbound closed before receiving peer's close_notify: possible truncation attack? Java 11 Error: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target I am using mutual authentication (two way authentication) for sending messages to syslog, Does NiFi support mutual authentication? Actually I am trying to replace LogStash with NiFi therefore mutual authentication part is critical -- Sent from: http://apache-nifi-users-list.2361937.n4.nabble.com/
