3256921 - Cloud Integration flow connection to external partner fails with SslHandshakeTimeoutException: handshake timed out after 10000ms

Cloud Integration flow has a HTTPS call to external system which fails with following error: 

io.netty.handler.ssl.SslHandshakeTimeoutException: handshake timed out after 10000ms

By further checking the message processing log of the message failed, following is shown for example:

     Error                       = io.netty.handler.ssl.SslHandshakeTimeoutException: handshake timed out after 10000ms
     ModelStepId            = MessageFlow_XX
     RealDestinationUrl   = https://{hostname}/{path}
     StepId                    = MessageFlow_XX
     Activities [
      {Activity=sap-util://storeHeaders?headers=CamelHttpUri,CamelHttpQuery,CamelHttpMethod, StartTime=Tue Mar 22 09:13:29.892 UTC 2022, StopTime=Tue Mar 22 09:13:29.893 UTC 2022}

      {Activity=setHeader[CamelHttpMethod], StartTime=Tue Mar 22 09:13:29.893 UTC 2022, StopTime=Tue Mar 22 09:13:29.893 UTC 2022}

      {Activity=ahc:https://{hostname}/{path}?clientConfig=#clientConfig_XXXXXXXXX&binding=#binding_XXXXXXXXX&clientConfig.requestTimeout=120000&clientConfig.pooledConnectionIdleTimeout=120000&clientConfig.readTimeout=120000&clientConfig.connectTimeout=10000, StartTime=Tue Mar 22 09:13:29.893 UTC 2022, StopTime=Tue Mar 22 09:13:39.946 UTC 2022}

In the activities section, the last activity, where there is clientConfig.connectTimeout=10000, that means 10 seconds, and difference of StartTime and StopTime of this activity is over the 10 seconds. 

The error can happen intermittently and all the time as well.

SAP Cloud Integration

SslHandshakeTimeoutException: handshake timed out after 10000ms, handshake timed out, SslHandshakeTimeoutException, io.netty.handler.ssl.SslHandshakeTimeoutException, clientConfig.connectTimeout=10000, StartTime, StopTime, SSL Handshake failure, connection timeout,  , KBA , LOD-HCI-PI-CON-HTP , HTTP Adapter , How To