Discrepancy in data read from xace and AcePerl

Ed Griffiths edgrif at sanger.ac.uk
Mon Feb 28 07:15:59 EST 2000


OK, here are some answers for the 4_7 version of the client/server
(which uses RPC for communication):

> Also, if someone knows the port number and ip address of a running AceDB
> server, is there any way to keep them from connecting to it ?

This version of the server used an ingenious method for restricting
read/write access which did not require the user to have a password. The
basic idea was that the server would write two magic files (one for
read, one for write) in a  directory(ies) known to the client and
server. If the client could read and return the contents of the read
file, it got read access, if it could read/return the contents of the
write file it got write access. Thus if the client and server were on
different machines then the directory where these files appeared had to
be NFS mounted by the two machines. So the answer to your question is
that you can restrict access if the client and server can see this
directory. You can give read access to everybody without them having to
see this directory. This is explained in the file wspec/server.wrm.

> Also, in the passwd.wrm file, you're supposed to list user ids with write
> access to the database.  I assume this is only for non-remote clients ?

You assume correctly, passwd.wrm file is used by the program actually
accessing the database (xace, tace, aceserver etc.).

> another machine.  Surely I don't have to NFS mount directories do I ?

The problem with this method (as you point out in a later note) is that
it doesn't allow that much control if NFS mounting is not possible. With
ace 4_7 I'm afraid you are just stuck with this.

Now...for ace 4_8 we have rewritten the server to directly use sockets
instead of RPC (for portability and interfacing reasons). We have also
taken the opportunity to add a password mechanism for users, so this
will answer your question. Now you will have a "true" client/server
setup with control files for restrict access to just the people you
want. There are new admin commands to manage these control files.

When this all be available ?  Well its available now for Beta-testing.
The caveat is that a number of other parts of acedb have been changed
and we are still testing locally to iron out bugs. I can build you a
binary (we are about to do a monthly build) and you can try it out if
you like. I am also just doing the documentation because we have added
some new commands to manage the user stuff and a number of other
additions to the server.

I hope this answers your questions, please feel free to email me direct
or append here if you need more information.

cheers Ed

| Ed Griffiths, Informatics
Group,                                             |
|               The Sanger Centre, Wellcome Trust Genome
Campus,               |
|               Hinxton, Cambridge CB10 1SA,
UK                                |
| email: edgrif at sanger.ac.uk      URL:
http://www.sanger.ac.uk/Users/edgrif    |
|   Tel: +44-1223-494780 (switch  +44 1223 834244) Fax: +44 1223
494919        |


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