Re: Problem with amtape "hanging" when forked from Java

At Thu, 10 Mar 2022 12:46:43 -0500 Nathan Stratton Treadway <[email protected]> wrote:

> 
> On Thu, Mar 10, 2022 at 09:55:30 -0500, Robert Heller wrote:
> > Here is the Java fragment:
> > 
> > public class FlushOldVaults extends BackupVault {
> >     private static final String AMTAPE = "/usr/sbin/amtape";
> >     private static final String AMTAPEOPT1 = "-otpchanger=vault_changer";
> >     private static final String AMTAPEOPT2 = "-ointeractivity=";
> 
> You would probably be able to confirm this by looking in the amanda
> log/debug files for the amtape process (i.e.
> /var/log/amanda/server/<CONFIG>/amtape.*.debug on Ubuntu) , but I'm pretty
> sure that you do actually need the empty argument in order to disable
> the interactivity, something like
>      private static final String AMTAPEOPT2 = "-ointeractivity=''";

It does not like the empty argument,  amtape throws a error status and the 
Java subprocess returns a failure status.  It is "happy" with what I have, 
except it hangs on the broken tape.

> 
> (I am not particularly certain that interactivity is your specific
> problem, but it seemed a plausible explaination and one that that was
> fairly easy to test out...)
> 
> 
> >         if (!p.waitFor(60L, java.util.concurrent.TimeUnit.SECONDS)) {
> >             System.err.printf("*** FlushOldVaults.amtape(): process timeout\n");
> >             String kill[] = new String[2];
> >             kill[0] = "/bin/kill";
> >             Long j = new Long(p.pid());
> >             kill[1] = j.toString();
> >             Process killproc = Runtime.getRuntime().exec(kill);
> >             killproc.waitFor();
> 
> Note that in order to use the strace debugging, you'll probably need to
> disable this timeout+kill logic -- otherwise the amtape process won't
> hang out long enough for you to figure out what it's trying to do when
> when it's "stuck"....

The timeout never times out.  The amtape process goes into Sleep state and the 
Java program just hangs.

> 
> 
> 						Nathan
> 
> 
> 
> 
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>                              
> 

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