my $cmd = "...";

my $out = $ssh->capture({timeout => 120}, $cmd);
unless (defined $out) {
  warn "unable to run command $cmd, retrying...";
  $ssh->restart or die "Unable to restart SSH connection: " . $ssh->error;
  $out = $ssh->capture({timeout => 120}, $cmd);
  unless (defined $out) {
    die "definitively, I can't run the command $cmd: " . $ssh->error;
  }
}