[vfs] File Monitor for an 'SFTP' file system times out occasionally and fails to recover

[KUMAR Saksham <sa...@thalesgroup.com>]

Hi,

While using the File Monitor for an 'SFTP' file system, we encounter the following error occasionally.


Could not determine the type of file "sftp://siq-perf<ftp://siq-perf/>:***@sftp.ggn.in.guavus.com/data/siq05_d/edrflow/edr-flow/0<mailto:***@sftp.ggn.in.guavus.com/data/siq05_d/edrflow/edr-flow/0>". SEVERE [106 2020-06-22 13:41:46.788]: org.apache.commons.vfs2.impl.DefaultFileMonitor check Could not determine the type of file "sftp://siq-perf<ftp://siq-perf/>:***@sftp.ggn.in.guavus.com/data/siq05_d/edrflow/edr-flow/0<mailto:***@sftp.ggn.in.guavus.com/data/siq05_d/edrflow/edr-flow/0>".
org.apache.commons.vfs2.FileSystemException: Could not determine the type of file "sftp://siq-perf<ftp://siq-perf/>:***@sftp.ggn.in.guavus.com/data/siq05_d/edrflow/edr-flow/0<mailto:***@sftp.ggn.in.guavus.com/data/siq05_d/edrflow/edr-flow/0>".
         at org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:1390)
         at org.apache.commons.vfs2.provider.AbstractFileObject.exists(AbstractFileObject.java:968)
         at org.apache.commons.vfs2.impl.DefaultFileMonitor$FileMonitorAgent.check(DefaultFileMonitor.java:496)
         at org.apache.commons.vfs2.impl.DefaultFileMonitor$FileMonitorAgent.access$200(DefaultFileMonitor.java:355)
         at org.apache.commons.vfs2.impl.DefaultFileMonitor.run(DefaultFileMonitor.java:318)
         at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.commons.vfs2.FileSystemException: Could not connect to SFTP server at "sftp://siq-perf<ftp://siq-perf/>:***@sftp.ggn.in.guavus.com/<mailto:***@sftp.ggn.in.guavus.com/>".
         at org.apache.commons.vfs2.provider.sftp.SftpFileSystem.getChannel(SftpFileSystem.java:159)
         at org.apache.commons.vfs2.provider.sftp.SftpFileObject.statSelf(SftpFileObject.java:106)
         at org.apache.commons.vfs2.provider.sftp.SftpFileObject.doGetType(SftpFileObject.java:76)
         at org.apache.commons.vfs2.provider.AbstractFileObject.getType(AbstractFileObject.java:1384)
         ... 5 more
Caused by: com.jcraft.jsch.JSchException: channel is not opened.
         at com.jcraft.jsch.Channel.sendChannelOpen(Channel.java:765)
         at com.jcraft.jsch.Channel.connect(Channel.java:151)
         at org.apache.commons.vfs2.provider.sftp.SftpFileSystem.getChannel(SftpFileSystem.java:133)
         ... 8 more

This error seems to repeat itself (with the File Monitor thread trying to get the file type again after timeout) endlessly to no end. However we are able to establish a sftp connection to the machine via the cli.

The issue usually arises when a bunch of files are moved onto the machine on which the File Monitor thread keeps checking for new files.

Any help with the same will be greatly appreciated.

Regards
Saksham Kumar