EmailDispatcher:172 - Unable to dispatch notification via Email javax.mail.MessagingException: Could not convert socket to TLS

[#1]

Hi

Not able to send mail alert through Amabri server. Facing below error.

EmailDispatcher:172 - Unable to dispatch notification via Email javax.mail.MessagingException: Could not convert socket to TLS

Java Version- 1.8.0_112

Amabri-server.log

---

ERROR [alert-dispatch-31] EmailDispatcher:172 - Unable to dispatch notification via Email
javax.mail.MessagingException: Could not convert socket to TLS;
nested exception is:
javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1999)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:709)
at javax.mail.Service.connect(Service.java:386)
at javax.mail.Service.connect(Service.java:245)
at javax.mail.Service.connect(Service.java:194)
at javax.mail.Transport.send0(Transport.java:253)
at javax.mail.Transport.send(Transport.java:124)
at org.apache.ambari.server.notifications.dispatchers.EmailDispatcher.dispatch(EmailDispatcher.java:160)
at org.apache.ambari.server.notifications.DispatchRunnable.run(DispatchRunnable.java:58)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1509)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:979)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:914)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)
at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:543)
at com.sun.mail.util.SocketFetcher.startTLS(SocketFetcher.java:480)
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1994)
... 11 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:387)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:230)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1491)
... 21 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:382)
... 27 more

[#2]

We see the error as:

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
     at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1999)

Which indicates that you might have configured Email notification on your ambari and your Email Server might be using Secure connections and hence you will need to make sure that you do these things first.

1. Export the Public SSL certificate of your email server

Example:

# echo | openssl s_client -showcerts -connect <EMAIL_SERVER_HOST>:<EMAIL_SERVER_SSL_PORT> 2>&1 | sed --quiet '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/email_server_certificate.cr

2. Configure a Truststore inside your Ambari Server

https://docs.hortonworks.com/HDPDocuments/Ambari-2.7.3.0/administering-ambari-views/content/amb_conf...

3. Import the public SSL certificate of your Email server in Ambari Server's Truststore.

.

Following are some discussion/article links where you can find how to Configure Ambari Server Truststore.

https://community.hortonworks.com/articles/39865/enabling-https-for-ambariserver-and-troubleshootin....

[#3]

@Samir Shaikh

Were you able to follow the above instructions , did it clear the error?