Hi Paul,
Just to add one more item which is related to the fact that you are using
just a data server. From an xrootd's client's perspective, it doesn't really
matter since the protocal explicitly says that redirectors and data servers
are interchangeable from a communications standpoint (functionally they are
not). For true xrootd clients that doesn't matter but for xrootdFS it does.
Again, it is related to how each one of these determines who it's talking
to.
To solve this particular problem you must make sure that the hostname
associated with the data server never maps to the public address via DNS.
The name that the server uses is the one returned by gethostname() which
normally corresponds to the one returned by the uname command. One
additional wrionkle here is that hostname is converted to an IP address and
then reconverted back to a hostname. This is standard practice in getting
the fully qualified name for a host. Again, the DNS mapping must be
consistent for this to work and should only use the private IP address.
Andy
-----Original Message-----
From: Paul T. Keener
Sent: Tuesday, April 26, 2011 7:16 PM
To: xrootd-l
Subject: Re: XrootdFS
I should add that this is with version 3.0.3 and I am not currently
running a redirector; xrootdfs is pointing directly to the data server.
Thanks.
-paul
On 4/26/2011 8:46 PM, Paul T. Keener wrote:
> I am having trouble with XrootdFS. In particular, I am trying to force all
> xrootd traffic over my private network. I can xrdcp using
> root://foo.at3f//scratch fine on a machine different from foo. However,
> if I try to use xrootdfs to mount this filesystem, and set XROOTDFS_RDRURL
> to "root://foo.at3f:1094//scratch" (or even replace "foo.at3f" with the IP
> address), it will mount the filesystem, but if I try to access it, I get
> syslogd messages:
>
> WARNING: stat(root://<Public IP>:0//scratch/) failed (connection timeout)
>
> Looking at the network traffic, it is clear that these xrootd requests are
> going over the public network interfaces. The timeout is then caused by
> the firewall.
>
> How do I force all communication between xrootdfs and the xrootd service
> to go over the private network? Moreover, how is xrootdfs getting the
> public IP address of the server?
>
> Thanks.
>
> Paul T. Keener
> Department of Physics and Astronomy
> University of Pennsylvania
