GDS Server Programs
A GDS server machine requires the following files:
admscheme, asn1_attr, common, countries, dirparam, gdscache,
gdscacheadm, gdscacheupd, gdschdb, gdscmxl, gdsconf, gdscrontab, gdscstub, gdsdaemon, gdsdbread, gdsdbwrite, gdsdeact,
gdsdirinfo, gdsdistcmd, gdsditadm, gdsdsa, gdsexec, gdsgendb, gdshdlcache, gdshdlupd, gdsinfo, gdsipcchk,
gdsipcinit, gdsipcstat, gdslanguage, gdslog, gdsmkiss, gdsmkupd, gdssstub, gdsstart, gdsstep, gdssysadm,
gdstransfer, gdsutil, ipcconf, newscheme, nsapmacros, osiforminfo
A machine that is configured as a GDS server runs the GDS client/server configuration, which consists of the following three parts:
· Server
- The gdsdsa program is the main DSA program; it forks as many DSA processes as are needed and it accesses the database.
- The gdsstub program is the process that receives incoming requests from clients and responds back to clients, and sends outgoing requests from servers to other servers and receives responses to these requests.
· Client
- An application, such as gdsditadm, links the DUA library.
- The gdscacheadm, gdscache, and gdscstub programs, which are described in DTS Client Programs, provide additional GDS client functionality.
· Per-machine utilities
- These utilities are the gdsipcchk and gdssysadm programs, which are described in DTS Client Programs.
You can have more than one GDS server (DSA) running in your cell. If you have more than one DSA, the data in the Directory Information Base (DIB), which is the GDS database, can be partitioned by storing a different part of the DIB on each server. Alternatively, the data can be replicated by storing copies of the DIB on several machines. A combination of partitioning and replication can also be used.
You need to plan what information you want to replicate and how the information is distributed. The master DSA is the only place where writes and updates can occur. Although you can access the master DSA from any client machine, if the master is unavailable no updates can be made. Therefore, you need to choose a dependable machine to run the master DSA. By creating shadows (replicas) of the master DSA you increase the reliability of read operations. By strategically placing shadows on the network you can improve access time for users.
Keep the following considerations in mind when planning for a DCE configuration that includes GDS:
· The initial installation takes approximately 20 megabytes. One database entry requires approximately 7 kilobytes. You must consider and allocate additional disk space depending on the amount of information you want to store in your directory.
· You must understand how CDS cell-related information is entered and displayed using the gsdcp program. (See the OSF DCE GDS Administration Guide and Reference for a description of the masks (menus) you use to enter this information.)
· You must know the IP address, port number (together, these two pieces of information are called the PSAP), and the cell name for each machine that has a DSA. (See the OSF DCE GDS Administration Guide and Reference for information about entering and displaying PSAP addresses using the gdsditadm or gdscacheadm GDS administration program.)