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3283317 - On-premise service access fails from SAP Business Application Studio due to TLS-terminating firewall/proxy


From Business Application Studio the on-premise system access fails.

Testing the backend system from BAS Terminal results in 503 HTTP code:

curl -v -i https://ABAP.dest/sap/opu/odata/iwfnd/catalogservice;v=2/ServiceCollection?%24top=1

HTTP/1.1 503 Service Unavailable

In SAP Cloud Connector log file such exception is logged:          #Received "open tunnel event" message (packet type: 1 (open tunnel)) for tunnel id account:///12345678-abcd-efgha-123456789abc and hostId null|          #Opening a tunnel to S4HANA System|          #Sending handshake request for tunnel: account:///12345678-abcd-efgha-123456789abc and host|

#WARN#io.netty.util.concurrent.DefaultPromise#tunnel-client-12-8#          #An exception was thrown by
java.util.concurrent.ExecutionException: PKIX path building failed: unable to find valid certification path to requested target
    at io.netty.util.concurrent.DefaultPromise.get(
Caused by: unable to find valid certification path to requested target
    ... 38 more|          #Unexpected exception while establishing tunnel connection for tunnel: account:///12345678-abcd-efgha-123456789abc SSLEngine closed already
    at io.netty.handler.ssl.SslHandler.wrap(



SAP Business Application Studio

SAP Cloud Connector


SAP Business Application Studio all versions ; SAP Cloud Platform Web IDE all versions


503 Service Unavailable, BAS, On-premise, Business Application Studio, Cloud Connector, HTTP 503, SCC, 503, Service Unavailable, Handshake Exception, SSL, SSLHandshakeException, Unexpected exception while establishing tunnel connection for tunnel, SunCertPathBuilderException, TLS, Proxy, Firewall , KBA , CA-BAS-SRVC , Consume SAP Services - SAP Business Application Studio , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , Problem

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