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Commands Reference, Volume 3
Administers the registration of
NCS-based servers in location broker databases.
lb_admin [ -nq ] [ -version ]
The lb_admin tool
administers the registrations of NCS-based servers in global location broker
(GLB) or local location broker (LLB) databases. A server registers
universal unique identifiers (UUIDs) specifying an object, a type, and an
interface, along with a socket address specifying its location. A
client can locate servers by issuing lookup requests to GLBs and LLBs.
The lb_admin tool can be used to look up information, add new
entries, and delete existing entries in a specified database.
The lb_admin tool is
useful for inspecting the contents of location broker databases and for
correcting database errors. For example, if a server terminates
abnormally without unregistering itself, use lb_admin to manually
remove its entry from the GLB database.
When accepting input or displaying
output, lb_admin uses either character strings or descriptive
textual names to identify objects, types, and interfaces. A character
string directly represents the data in a UUID in the format
xxxxxxxxxxxx.xx.xx.xx.xx.xx.xx.xx.xx
where each x is a hexadecimal
digit. Descriptive textual names are associated with UUIDs in the
uuidname.txt file.
The lb_admin command
examines or modifies only one database at a time. This is referred to
as the current database. The use_broker command
selects the type of location broker database, GLB or LLB. The
set_broker command selects the host whose GLB or LLB database is to
be accessed. If one replica of a replicated GLB database is modified,
the modifications are propagated to the other replicas of that
database.
| -nq
| Do not query for verification of wildcard expansions in unregister
operations.
|
| -version
| Display the version of NCS that this lb_admin belongs to, but
do not start the tool.
|
In the lookup, register, and unregister
commands, the object, type, and interface
arguments can be either character strings representing UUIDs or textual names
corresponding to UUIDs, as described earlier.
| a[dd]
| Synonym for register.
|
| c[lean]
| Finds and deletes obsolete entries in the current database. When
issuing this command, lb_admin attempts to contact each server
registered in the database. If the server responds, the entry for its
registration is left intact in the database. If the server does not
respond, lb_admin tries to look up its registration in the LLB
database at the host where the server is located, tells the result of this
lookup, and asks if the entry is to be deleted. If a server responds,
but its UUIDs do not match the entry in the database, lb_admin
tells this result and asks if the entry is to be deleted.
There are two situations in which it is likely that a database entry should
be deleted:
- The server does not respond.
lb_admin succeeds in contacting the LLB at the host where the
server is located, but the server is not registered with that LLB. The
server is probably no longer running.
- Server responds, but its UUIDs do not match the entry
in the database. The server that responded is not the one that
registered the entry.
Entries that meet either of these conditions are probably safe to
delete.
In other situations, it is best not to delete the entry unless it can be
verified directly that the server is not running (for example, by listing the
processes running on its host).
When lb_admin asks to
delete an entry, there are four ways to respond. A
y[es] response deletes the entry. A
n[o] response leaves the entry intact in the
database. After a yes or a no, lb_admin proceeds to check
the next entry in the current database. A g[o]
response invokes automatic deletion, in which all eligible entries are deleted
and all ineligible entries are left intact, without the user being queried,
until all entries have been checked. A q[uit]
response terminates the clean operation.
|
| d[elete]
| Synonym for unregister.
|
| h[elp]
[Command] or ? [Command]
| Displays a description of the specified Command or, if none is
specified, list all of the lb_admin commands.
|
| l[ookup] Object Type Interface
| Looks up and displays all entries with matching Object,
Type, and Interface fields in the current
database. An asterisk can be used as a wildcard for any of the
arguments. If all the arguments are wildcards, lookup
displays the entire database.
|
| q[uit]
| Exits the lb_admin session.
|
| r[egister]
Object Type Interface Location Annotation [Flag]
| Adds the specified entry to the current database. Use an asterisk
to represent the nil UUID in the Object, Type, and
Interface fields.
The location is a string in the
format Family:Host[Port], where Family
is an address family, Host is a host name, and Port is a
port number. Possible values for Family include
ip. A leading # can be used to indicate that a
host name is in the standard numeric form. For example,
ip:vienna[1756] and
ip:#192.5.5.5[1791] are acceptable
location specifiers.
The Annotation is a
string of up to 64 characters annotating the entry. Use double
quotation marks to delimit a string that contains a space or contains no
characters. To embed a double quotation mark in the string, precede it
with a backslash.
The Flag is either local (the default) or
global, indicating whether the entry should be marked for local
registration only or for registration in both the LLB and GLB
databases. The Flag is a field that is stored with the entry
but does not affect where the entry is registered. The
set_broker and use_broker commands select the particular
LLB or GLB database for registration.
|
| s[et_broker] [BrokerSwitch]
Host
| Sets the host for the current LLB or GLB. If specifing global as
the BrokerSwitch, set_broker sets the current GLB;
otherwise, it sets the current LLB. The host is a string in the format
Family:Host, where Family is an address family and
Host is a host name. Possible values for Family
include ip. A leading # can be used to indicate
that a host name is in the standard numeric form. For example,
ip:prague and ip:#192.5.5.5
are acceptable host specifiers.
Issue use_broker, not
this command, to determine if subsequent operations will access the LLB or the
GLB.
|
| set_t[imeout] [short |
long]
| Sets the timeout period used by lb_admin for all of its
operations. With an argument of short or long,
set_timeout sets the timeout accordingly. With no argument,
it displays the current timeout value.
|
| u[nregister] Object Type Interface
Location
| Deletes the specified entry from the current database.
The location is a string in the
format Family:Host[Port], where Family
is an address family, Host is a host name, and Port is a
port number. Possible values for Family include
ip. A leading # can be used to indicate that a
host name is in the standard numeric form. For example,
ip:vienna[1756] and
ip:#192.5.5.5[1791] are acceptable
location specifiers.
An asterisk can be used as a
wildcard in the Object, Type, And Interface
fields to match any value for the field. Unless queries have been
suppressed by invoking lb_admin with the -nq option,
unregister allows deletion of each matching entry. A
y[es] response deletes the entry. A
n[o] response leaves the entry in the database. A
g[o] response deletes all remaining database entries
that match, without querying. A q[uit] response
terminates the unregister operation, without deleting any
additional entries.
|
| us[e_broker] [BrokerSwitch]
| Selects the type of database that subsequent operations will access, GLB
or LLB. The BrokerSwitch is either global or local.
If a BrokerSwitch is not supplied, use_broker determines
if the current database is global or local.
Use set_broker to
select the host whose GLB or LLB is to be accessed.
|
The drm_admin (NCS) command
The glbd (NCS) daemon, llbd (NCS) daemon, nrglbd (NCS) daemon.
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