SDSS Science Archive Versions Page
This page is for the SDSS Collaboration use only. It provides the status of the
various versions of the Science Archive (SX) database available to the
collaboration currently, and provides links to them or information about them
Status of SX (EDR and Chunk Servers)
There are three SX databases in existence currently:
- the Early Data Release (EDR) version, which contains
the latest reruns (Photo v5.2) of the public subset of the SDSS
- the fermiChunk (chunk) version has now been
updated to the latest software and data model versions, and has been reloaded
as of 12/01. See Brian
Yanny's message (#94) in the sdss-sxuser archive.
- the fermiStage (staging) version released 10/01. See Brian
Yanny's message (#71) in the sdss-sxuser archive.
Each version basically consists of three products:
The EDR SX and the EDR atlas
images and spectra represent the latest reruns and the most complete dataset
currently in existence. All EDR products are also available
from the MAST SDSS web
page (http://archive.stsci.edu/sdss/). For the latest status
on the collaboration databases, see the SX@Fermi
The Catalog Archive Server (CAS) - this is the SX.
The Data Archive Server -
the atlas images, spectra and corrected frames server.
The skyServer - the SQL Server interface to the
data (currently available only for the EDR version) via the web.
Everyone should upgrade to the latest version (v2.3.15) of
the SX query tool sxQT, now also known as sdssQT. The latest
version can be obtained from CVS (cvs export -r v2_3_15 sxQT)
or from the SX download page at http://www.sdss.jhu.edu/sx/download/latest/.
The server coordinates for the EDR, chunk and staging main
servers and the EDR/chunk/stage proxlist servers are:
* The server entry in your sdssQT can be called
whatever you like (except for the ProxList entry, see below) as long as it
points to the correct Port Daemon host, Port Daemon port, and Port Daemon
ID. For example, the server entry for the new chunk server is called
fermiChunk8 by default, even though it points to Port Daemon ID
Port Daemon Host
Port Daemon Port
Port Daemon ID
** Only the ProxList entry can point to a proxlist
server. Using some other entry (i.e.calling it something other than
ProxList) will not work. Unfortunately, this means that you
have to reconfigure the ProxList entry each time you change the proxlist
server you want it to point to.
These entries are listed in your $HOME/.sxSites (plural) file. Only the EDR and
EDR ProxList entries are there by default. Your current default site choice
is saved in the $HOME/.sxSite (singular) file.
You can create or change server entries using the Configure
Server->Add/Modify Server by hand option in the File menu, or just
edit the file in emacs.
Except for the ProxList entry (as described in above footnote), other server
entries may be called whatever you like, as long as they point to the correct
Port Daemon ID.
Current Version, released Feb 27, 2002 (v2.3.18)
The collaboration's Catalog Archive Servers (SX) - the chunk and the
stage servers, as well as the EDR are all running v2.3.18 of
the SX software. This version contains several important bug fixes and
stability enhancements - see the archived
release note and follow-up
to that message.
Original EDR Version released 06/2001 (v2.3.5)
The EDR version (v2.3.5) contained the updated
data model (http://www.sdss.jhu.edu/sx/sdssqt/classes.html)
and upgrades to the software. Although originally the EDR was going
to be released with the Java version of the query tool (renamed sdssQT
for the EDR), the problems with the java version forced
us to revert to the Tcl/Tk version, which was also upgraded for v2.3.5.
(Note: The original EDR version of the sdssQT is no longer
available at the SX
download page and has been superseded by v2.3.15.) Version 2.3.5 of
the software added the following features:
Firewall safety: In the previous
version of the SX server and the sxQT, the connection for the query output
was initiated by the server, i.e., the server used to open a socket
on a predefined port on the client machine. This required a hole
to be punched in the client-side firewall, if there was one. Version
2.3.5 fixes this problem, and the server now listens on a socket and waits
for the client to initiate the connection. Since this required a
change to both the client (sxQT) and the server, the new sxQT will not
work with the old server (e.g. FermilabChunk) unless it is invoked with
the command-line option "-oldserver", e.g.:
sxQT -oldserver &
When invoked with this option, the sxQT reverts to the old
mode that requires a hole in the client's firewall.
SIGPIPE handling: When the client
drops the connection without first sending an end-session directive (for
example when the sxQT is killed in mid-session with ^C or a logout or kill
command), or the connection drops for any other reason, a UNIX signal (SIGPIPE)
is sent to the server. The multi-threaded server was not handling
this properly and used to crash very often when this happened.
This was especially troublesome when the Java version of the query tool
was made available to the collaboration for testing, since it had a bug
that caused it to drop the connection in this way every time it timed out.
This caused the chunk server to crash pretty much every time someone used
the java query tool to connect to it. Version 2.3.5 fixes this problem
Public user: The EDR server also recognizes the public
SDSS user (userid: sdss, passwd: sdss),
so you do not need an SX account to access it.
Compatibility with new data model: The EDR server
recognizes the updated data model (see below).
Query Tool upgrades: Version 2.3.5 of the sxQT/sdssQT
also contains other enhancements apart from firewall-safety. Most
importantly, it incorporates a session timeout of 10 minutes.
You can reconnect easily using the server connection button or menu option.
Reconnection is also automatic if you submit a query.
Bug fixes: The EDR version contains several
bug fixes in addition to the SIGPIPE bug, notably fixes for server hangs
on certain queries.
data model contains the following changes:
To make the EDR more politically correct, the "sx" prefix
was dropped from all the class names. However, the "sx" names were
retained as aliases for backwards compatibility, so that existing queries
would not have to be changed.
has been expanded and renamed PhotoTag.
This was in response to the requests from the collaboration over the past
year to include more frequently-searched quantities into the tag objects.
Please see the new
PhotoTag class on the web page for all the new fields that have been
added to it.
The 32-bit flags have now been combined into one 64-bit flag,
in the PhotoTag
class, flag1 + flag2 ---> objFlags,
in the PhotoObj
class, objFlags + objFlags2 ---> objFlags, and,
flags + flags2 ---> flags.
The old flag names have been kept as aliases for backwards
compatibility, so that existing queries do not need to be changed.
subclass of sxTag
has been replaced by Family,
have been dropped.
The only change incompatible with the previous version (the
one that is in the chunk server) is that in the PhotoObj,
the long object ID (first field) has now been renamed objID instead of
object_ID. Since this clashed with the existing object-number within
the field, the latter has been renamed "object" and aliased to "objid"
and "id". Hence "objID" is the long bit-encoded id, and "object"
is the number of the object within the field. This is to keep it
consistent with Field.field
Ani R. Thakar
Last updated Feb 28, 2002