Important Notes

• 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:

 

Server Entry*	Port Daemon Host	Port Daemon Port	Port Daemon ID
EDR	sdssdp5.fnal.gov	2005	fermiEDR
ProxList**	sdssdp5.fnal.gov	2005	fermiEDRProxList
Chunk	sdssdp8.fnal.gov	2005	fermiChunk
ProxList**	sdssdp8.fnal.gov	2005	fermiChunkProxList
Stage	sdssdp6.fnal.gov	2005	fermiStage
ProxList**	sdssdp6.fnal.gov	2005	fermiStageProxList

*  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 "fermiChunk".
**  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:
1. 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.
 

2. 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 as well.
   
   
3. 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.
   
   
4. Compatibility with new data model: The EDR server recognizes the updated data model (see below).
   
   
5. 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. 
   
   
6. Bug fixes: The EDR version contains several bug fixes in addition to the SIGPIPE bug, notably fixes for server hangs on certain queries.


The new data model contains the following changes:

1. 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.
2. The Tag class 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.
3. The 32-bit flags have now been combined into one 64-bit flag, so that

        in the PhotoTag class, flag1 + flag2 ---> objFlags,
        in the PhotoObj class, objFlags + objFlags2 ---> objFlags, and,
                                                 flags[5] + flags2[5] ---> flags[5].
The old flag names have been kept as aliases for backwards compatibility, so that existing queries do not need to be changed.
4. The sxBad subclass of sxTag has been replaced by Family, and sxBright and sxNonBright have been dropped.
5. 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 and Run.run.

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Ani R. Thakar
Last updated Feb 28, 2002