jsch ChannelExec run a .sh script with nohup "lose" some commands

Question

I hava a .sh script which glues many other scripts, called by jsch ChannelExec from a windows application.

Channel channel = session.openChannel("exec");

((ChannelExec) channel).setCommand("/foo/bar/foobar.sh");

channel.connect();

if I run the command like "nohup /foo/bar/foobar.sh >> /path/to/foo.log &", all the long term jobs(database operations, file processing etc.) seems to get lost.

checking the log file, only find those echo stuffs(before and after a long term operation, calculate running time etc.).

I checked the permissions, $PATH, add source /etc/profile to my .sh yet none of these works.

but when I run the command normally (sync run, print all echo outputs to my java client on windows),all the things goes well.

it's a really specific prob. Hope someone with experience can help me out.

thank in advance.

Han

Are you sure that they get lost, or could it be that they simply are still running when you check the output? — Paŭlo Ebermann, Jun 03 '11 at 11:28
Also, try the same with a stock `ssh` client to see if it is related to JSch (I suppose not). — Paŭlo Ebermann, Jun 03 '11 at 11:30
hi. I can make sure that they are lost. Some records ought to be loaded into the database if they worked. — Han Zheng, Jun 04 '11 at 09:17
I tried to use ChannelShell to execute those commands, and everything goes well. After some test, I found I must wait on the client side for some commands to print outputs, even if I use nohup mode. I'll keep testing... — Han Zheng, Jun 04 '11 at 09:35

score 6 · Accepted Answer · edited Jun 09 '11 at 14:03

Solved!

A different issue that often arises in this situation is that ssh is refusing to log off ("hangs"), since it refuses to lose any data from/to the background job(s).[6][7] This problem can also be overcome by redirecting all three I/O streams.

from http://en.wikipedia.org/wiki/Nohup

My prob is, psql and pg_bulkload print their outputs to err stream.

In my script, I didn't redirect err streams.

Everything went fine by also redirecting err streams to the same log file.

nohup foo.sh > log.log 2>&1 &

Thanks to Atsuhiko Yamanaka, he created a great JSch library, and Paŭlo Ebermann for the documentation.

`nohup foo.sh > log.log 2>&1 &` save me a whole day! – LoranceChen Feb 17 '18 at 11:43 — LoranceChen, Feb 17 '18 at 11:43

jsch ChannelExec run a .sh script with nohup "lose" some commands

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