Server configuration
Once storage space has been created a names file is then constructed for
the server. Below is an example names file for a server. This particular
names files contains entries for two databases one for calibration and one
for a geometric database. (The next section of the tutorial will
demonstrate the creation of these database files.)
An example names file for calib and geom dbs files
:nick.config
:list.ge ca
:log./hepdb/expdb/logs
:bad./hepdb/expdb/bad
:todo./hepdb/expdb/queue
:queue./hepdb/expdb/queue
:save./hepdb/expdb/save
:logl.3
:wakeup.60
:nick.ge
:file..GEO.dbs
:desc.Geometric database (residing on VM)
:servers.caliblist1
:nick.ca
:file./hepdb/expdb/CAL.dbs
:desc.Calibration Database
:servers.caliblist2
:nick.caliblist1
:list.ecal1 ecal2
:nick.caliblist2
:list.ecal2
:nick.ecal1
:userid.cdl3
:node.hepdb
:localq./hepdb/l3/todo
:nick.ecal2
:userid.cdl3
:node.vxl3on
:queue.disk$db:[cdl3.todo]
:transport.tcpip
:localq./hepdb/l3/tovxl3on
To understand the way the server uses the information in the names file
one needs to examine the individual tags within it. A brief description of
these tags starting with those in the configuration block follows however
a more detailed account of this file can be found elsewhere in this text.
- CONFIG
- Indicates the start of the server
configuration details.
- LIST
- A list of two character database prefixes. These
prefixes act as a pointer within the names file giving specific details
about each database file.
- LOG
- The directory where the server logs are written
- BAD
- The directory where the server places bad updates
- QUEUE
- The directory where new updates are placed by
HEPDB clients
- TODO
- The directory which the server scans for new
updates. If this is the same as the QUEUE directory then the server
operates as the database master. In other cases it will operate in slave
mode.
- SAVE
- The directory where the server saves updates
after processing
- LOGL
- The log level for the server
- WAKEUP
- The wakeup interval in seconds for the server
The next type of block in the names file are the database files blocks,
identified by the string :nick.xx where xx is the two character database
prefix discussed above.
- :nick.xx
- The two character database prefix, e.g. ca.
- FILE
- The full path name of the database file. For
VM/CMS systems, the syntax is filename.filetype
- DESC
- Gives a brief description of the database
contents. It provides a way of documenting the names file.
- SERVERS
- The name specified in this tag is a pointer
to a list of remote servers. In our example file above the description of
our calib.dbs file refers to a serverlist caliblist1 which itself then
points to details of the two remote servers ecal1 and ecal2.
The remaining entries in our example names file are server descriptions.
These are identified by an entry :nick.servername and store details of
remote servers.
- server
- The nickname of the servers, e.g. ecal1.
- USERID
- Userid under which the server runs on the
remote node
- NODE
- Node on which the server runs
- QUEUE
- Input queue on the remote node
- TRANSPORT
- Method by which updates are transmitted
- LOCALQ
- The local directory where updates are written
pending transmission to the remote node. This may, in fact, be the same as
QUEUE, e.g. when the directory is accessible via NFS or AFS.
Starting the server
Finally we must start the server up. According to the platform you are
using the command to do this will vary slightly . The main forms of the
command follow:
- UNIX and VMS
The server can be run in the background or in batch mode.
- VM
On VM the server can be started in one of two ways. You could autolog
the machine CDexperiment (eg: CDEXPDB), or alternatively you could
log on as for example CDEXPDB, type HDBSTART and then exit the
session via the command #CP DISC.