Debugging an FTP Connection for scheduled report jobs

Issue:

TIBCO JasperReports® Server allows report jobs to be scheduled to an FTP Server as an output destination. 

How to best debug an FTP connection issues upon encountering any errors with the scheduled jobs? 

One such use case is when users are able to configure scheduled report jobs with multiple FTP connections connecting to different FTP Servers. 

The standard set of logging components does not log the ip address to be able to track which FTP Server the connection was made. 

Are there any additional logging that can be set to generate further debugging information ? 

Solution:

In the "Output Options" page, there is a "Test Connection" button that can test for connection failures. 

Below are the typical errors that can be generated in the ../WEB-INF/logs/jasperserver.log upon clicking on "Test Connection" :

2020-06-12T11:19:20,472 ERROR SecureExceptionHandlerImpl,http-nio-8080-exec-4:116 - Auth fail

2020-06-12T11:20:28,072 ERROR SecureExceptionHandlerImpl,http-nio-8080-exec-3:116 - No such file

2020-06-12T11:24:07,180 ERROR SecureExceptionHandlerImpl,http-nio-8080-exec-2:116 - java.net.ConnectException: Connection refused: connect

2020-06-12T11:28:14,744 ERROR SecureExceptionHandlerImpl,http-nio-8080-exec-4:116 - java.net.UnknownHostException: 172.17.18.6767

The conditions for when the above errors would be generated are:

• When directory is invalid, the "No such file" error 
• When username or password is invalid, the "Auth fail" error
• When port is invalid, the "Connection refused: connect" error 
• When server address is invalid, the "java.net.UnknownHostException"

For further debugging to be logged, the following logger component can be manually added to the "Server Settings" -> "Log Settings" to log extra FTP specific debug information (such as IP address) to the jasperserver.log:

com.jaspersoft.jasperserver.api.engine.common.util.impl.FTPUtil

An example is when the connection is successful it logs the IP and further DEBUG messages following the successful connection:

2021-05-18T19:27:28,273 DEBUG FTPUtil,JasperServerScheduler_Worker-2:236 - FTP: connected to 172.17.18.204 LOGIN OK.
2021-05-18T19:27:28,274 DEBUG FTPUtil,JasperServerScheduler_Worker-2:246 - Connected to 172.17.18.204 REPLY OK.

For multiple FTP Servers, this extra level of information would be handy to know which FTP Server a report job was connected to.

The debug information is based on specific conditions written inside the class, com.jaspersoft.jasperserver.api.engine.common.util.impl.FTPUtil (packaged inside ..WEB-INFlibjasperserver-api-engine-impl-7.9.0.jar). 

An extract of the code is pasted below:

public class FTPServiceClientImpl
implements FTPService.FTPServiceClient
{
private FTPClient ftpClient = null;

public FTPServiceClientImpl(String host, int port, String userName, String password)
throws Exception
{
this.ftpClient = new FTPClient();
this.ftpClient.connect(host, port);
if (!this.ftpClient.login(userName, password))
{
this.ftpClient.logout();
throw new JSException("FTP: Fail to login: may due to invalid username/ password.");
}
if (FTPUtil.log.isDebugEnabled()) {
FTPUtil.log.debug("FTP: connected to " + host + " LOGIN OK.");
}
int reply = this.ftpClient.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply))
{
this.ftpClient.disconnect();
throw new JSException("FTP: unable to connect to " + host);
}
if (FTPUtil.log.isDebugEnabled()) {
FTPUtil.log.debug("Connected to " + host + " REPLY OK.");
}
this.ftpClient.enterLocalPassiveMode();