One of my build agents is receiving this error intermittently. Is there a reason that this error would occur inconsistently?

[James Brown]

This question is in reference to Atlassian Documentation: Unable to Connect to SSL Services due to PKIX Path Building Failed

One of my build agents is receiving this error intermittently. Is there a reason that this error would occur inconsistently?

ERROR [0-BAM::XXX::Agent:pool-3-thread-1] [BambooArtifactHttpTransport] 
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

[Rich Duncan]

If the agent is connecting to a server using SSL and the certificate is signed by a known CA, you will get this error.  Is there a possibility that there are different certificates involved, as in 2 different apache servers that are load balancing traffic to bamboo?

[James Brown]

We have a reverse proxy server that has the SSL Certs on it and each of the tools behind it.  This only happens one out of every 10 times the tries the agent tries to download the artifacts from the Bamboo server. It also seems to occur when it has failed over.  We did not change any of the default failover settings.  Is this something that we should be configuring?