SFTP Smart Services

Hi,

We are getting an unexpected error when using the Send File Over SFTP smart service (using a private key). We have a requirement to send some files to an external SFTP server and for some of them it works fine and almost instantly (small files), but when using bigger files (the file size can vary from some KB to even MB in some cases) the node will take way more time to complete (some minutes, regardless of the file size) and report the FAILED flag with the following error: "java.io.IOException: inputstream is closed". This is not something that happens randomly, it always fails for those files. The external SFTP server is not managed by us, but their IT team told us logs show that the connection is being closed abruptly.

 This issue only happens with this smart service, the rest of them works fine against that server.

Log trace:

2022-04-27 14:47:42 INFO [Appian Work Item - 510542 - execution01 : UnattendedJavaActivityRequest] com.appiancorp.a2.vpn.VPNTunnelNameService.lookupAllHostAddr VPN dns lookup result (private server IP)
2022-04-27 14:52:46,850 [Appian Work Item - 510542 - execution01 : UnattendedJavaActivityRequest] ERROR com.appian.ps.plugins.sftpsmartservices.SendFileOverSFTP - Error transferring file to SFTP server
4: java.io.IOException: inputstream is closed
	at com.jcraft.jsch.ChannelSftp._put(ChannelSftp.java:697)
	at com.jcraft.jsch.ChannelSftp.put(ChannelSftp.java:540)
	at com.jcraft.jsch.ChannelSftp.put(ChannelSftp.java:492)
	at com.appian.ps.plugins.sftpsmartservices.SendFileOverSFTP.run(SendFileOverSFTP.java:150)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor$1.lambda$call$0(DefaultActivityExecutor.java:136)
	at com.appiancorp.plugins.PluginUsageLogger.runWithPluginInformation(PluginUsageLogger.java:52)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor$1.call(DefaultActivityExecutor.java:136)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor$1.call(DefaultActivityExecutor.java:130)
	at com.appiancorp.common.ContextClassLoaderSwitcher.runInContext(ContextClassLoaderSwitcher.java:27)
	at com.appiancorp.process.runtime.framework.DefaultActivityExecutor.execute(DefaultActivityExecutor.java:130)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequest.execute(UnattendedJavaActivityRequest.java:88)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequestResponseCreator.getJavaActivityResultResponse(UnattendedJavaActivityRequestResponseCreator.java:21)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequest.getJavaActivityResultResponse(UnattendedJavaActivityRequest.java:67)
	at com.appiancorp.process.engine.UnattendedJavaActivityRequest.execute0(UnattendedJavaActivityRequest.java:55)
	at com.appiancorp.common.persistence.data.AppianDataUserContextProvider.executeWithConsistentDataReads(AppianDataUserContextProvider.java:116)
	at com.appiancorp.process.engine.ProcessContinuationRequest.executeOuter(ProcessContinuationRequest.java:68)
	at com.appiancorp.process.engine.ContinuationRequest.execute(ContinuationRequest.java:124)
	at com.appiancorp.process.workpoller.UnattendedRequestHandlerBean.onMessage(UnattendedRequestHandlerBean.java:36)
	at com.appiancorp.process.workpoller.WorkItem.run(WorkItem.java:94)
	at org.springframework.jca.work.SimpleTaskWorkManager$DelegatingWorkAdapter.run(SimpleTaskWorkManager.java:239)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:750)
Caused by: java.io.IOException: inputstream is closed
	at com.jcraft.jsch.ChannelSftp.fill(ChannelSftp.java:2911)
	at com.jcraft.jsch.ChannelSftp.header(ChannelSftp.java:2935)
	at com.jcraft.jsch.ChannelSftp.checkStatus(ChannelSftp.java:2473)
	at com.jcraft.jsch.ChannelSftp._put(ChannelSftp.java:686)
	... 22 more

Hi Iván García, 

We will analyse the issue and get back to you.

Hello. 

Have you had the opportunity to look into this issue? Seems to be a common item among many Plug-In users. Please advise if so, thank you. 

Good morning,

Any update about this?

Hi Ivan Garcia,

Sorry for the delay. We were analysing this issue but in between we got stuck with other priority work items. We will look into this issue once we complete them and we will reply you by early next week

Hi,

Did you manage to reproduce the error? Any updates?

Hi,

We are getting that error when trying to upload files with size of 8kb or more to an external SFTP server. Other uploading methods against that server (for example, via sftp utilities or cmd) work fine. Sent attached an example of a file that shows the problem when uploading through the plugin, but with the command line tool it is uploaded succesfully.

exceltest.xlsx

Hi,
Please share us with the steps to reproduce the issue because we cannot reproduce the issue from our side. Thanks.

Hi,
Please share us with the steps to reproduce the issue because we cannot reproduce the issue from our side. Thanks.

Hello. 

Have you had the opportunity to look into this issue? Seems to be a common item among many Plug-In users. Please advise if so, thank you. 

Good morning,

Any update about this?

Hi Ivan Garcia,

Sorry for the delay. We were analysing this issue but in between we got stuck with other priority work items. We will look into this issue once we complete them and we will reply you by early next week

Hi,

Did you manage to reproduce the error? Any updates?

Hi,

We are getting that error when trying to upload files with size of 8kb or more to an external SFTP server. Other uploading methods against that server (for example, via sftp utilities or cmd) work fine. Sent attached an example of a file that shows the problem when uploading through the plugin, but with the command line tool it is uploaded succesfully.

exceltest.xlsx