Oracle SNMP Support Reference Guide Release 8.1.5 A67822-01 |
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This appendix provides information to help you interpret individual variables in the private Oracle Network Listener MIB. Specifically, it includes sections covering MIB variables in the following tables
For more information about the Oracle network listener, see Understanding SQLNet.
The oraListenerTable contains information about the generic network listeners installed on a managed node. A network listener is a server process that listens for connection requests for one or more databases on one or more network protocols. Monitoring a listener is important in order to ensure adequate database access.
Each entry in the oraListenerTable represents the network listener for a current database instance on the node. Each entry is indexed by oraListenerIndex. The current value of each oraListenerTable variable is retrieved from either configuration files or calculated from an internal buffer of the managed listener.
Table B-1 lists the variables included in the oraListenerTable.
A description of each of these variables follows.
INTEGER (1..2147483647)
read-only
A numeric index, unique among all generic listeners on this managed node, as retrieved from the snmp.index.listener-name parameter of the SNMP.ORA configuration file. oraListenerIndex also serves as the primary index for the oraListenAddressTable.
varies, depending on the value set in the snmp.index.listener-name field of the SNMP.ORA file
very important
oraListenAddress
not applicable
DisplayString
read-only
Indicates the name of this generic listener, as retrieved from the LISTENER.ORA configuration file.
1 - 255 characters
very important
none
icon or simple string
DisplayString
read-only
Indicates the version number of this generic listener, in vendor-specific format. This value is retrieved from an internal listener table.
30 - 50 characters (physical limit is 255 characters)
less important
none
simple string
DisplayString
read-only
Indicates the date and time at which this generic listener was started, as retrieved from an internal listener table. The format is date-month-year hours:minutes:seconds.
15 - 20 characters (physical limit is 255 characters)
less important
none
simple string
TimeTicks
read-only
Indicates the value of sysUpTime at the time the generic listener was started. This value is derived from the master agent, which counts the time in hundredths of a second since the master agent was started. The value of this variable should remain as a constant across the Listener's life span. A change in this variable indicates that the counter has been refreshed.
0 - 4249467295
important
none
clock
INTEGER (1 - 17)
read-write
Indicates the level at which a Listener should be traced. A value of 4 means that tracing at the USER level is turned on; and 6 means that tracing at the ADMIN level is turned on. A value of 17 means that tracing is turned off.
enumerated 1 - 17
important
oraNavigatorTraceFile
as an icon, or as a simple string of characters, OFF, USER or ADMIN
INTEGER (1) on, or (2) off.
read-only
Indicates whether or not the generic listener is password-protected, as determined from the PASSWORDS_listener_name parameter of the LISTENER.ORA configuration file. If security is ON (1), the password is required to perform certain DBA tasks against the Listener using the Listener control utility.
enumerated 1 or 2
less important
none
simple string
DisplayString
read-only
Indicates the name of the Listener configuration file on the managed node, as retrieved from an internal buffer of the managed listener. Default is $ORACLE_HOME/network/admin/listener_name.ORA
40 - 70 characters (physical limit is 255 characters)
important
none
simple string
DisplayString
read-only
Indicates the directory for the log file that is automatically generated for listener events, as retrieved from the LOG_DIRECTORY parameter of the LISTENER.ORA configuration file. Default is operating system specific: on UNIX, for example, it is $ORACLE_HOME/network/log/listener_name.log.
20 - 70 characters (physical limit is 255 characters)
less important
none
simple string
DisplayString
read-only
Indicates the name of the file to which trace information is written, as determined from the TRACE_FILE parameter of the LISTENER.ORA configuration file. Default is $ORACLE_HOME/network/trace/listener_name.trc
20 - 70 characters (physical limit is 255 characters)
less important
oraListenerTraceLevel
simple string
INTEGER (1) up, or (2) down
read-only
Indicates the current state of the generic listener, as retrieved from an internal table. The DOWN value (2) indicates that the generic listener is not available for any use, but is known to the agent. The UP value (1) indicates that the generic listener is running and available for generic use. This value would be inspected by an agent on receipt of an oraListenerStateChange trap.
enumerated 1 or 2
important
oraListenerStateChange
simple string or icon
INTEGER (0..2147483647)
read-only
Indicates the number of different types of services, dedicated server, dispatcher, or prespawned shadow, configured with the listener:
1 - 25, depending on the configuration parameters
less important
none
simple string
DisplayString
read-write
Free-form text providing contact information for this managed listener, including name, telephone number, email address, for example. This value is retrieved from the snmp.contact.listener_name parameter of the SNMP.ORA configuration file.
0 - 255 characters
less important
none
simple string
The oraSIDTable contains information about the status of connections to a current database instance. This information is important to monitor in order to ensure that clients seeking access to a database have that opportunity.
Each entry in the oraSIDTable represents a current database instance for whom the listener listens. Each entry is indexed by oraSIDName.
Table B-2 lists the variables included in the oraSIDTable.
A description of each of these variables follows.
INTEGER (1..2147483647)
read-only
A numeric index, unique among all of the generic listeners on the managed node, that associates a listener with a database it listens on. This value is retrieved from the snmp.index.listener_name parameter of the SNMP.ORA configuration file.
varies, depending on the value set in the snmp.index.listener-name field of the SNMP.ORA configuration file
very important
oraListenerIndex
not applicable
DisplayString
read-only
A unique name identifying a database instance. This SID is in the definition of the listener, as retrieved from the SID_NAME parameter of the LISTENER.ORA configuration file. oraSIDName serves as the primary index in the oraDedicatedSrvTable, oraDispatcherTable, and oraPrespawnedSrvTable; thus, an entry for any dispatcher, dedicated server or prespawned server which listens for the database instance identified by oraSIDName can be found.
1 - 25 characters (physical limit is 255 characters)
very important
oraDedicatedSrvIndex, oraDispatcherIndex, oraPrespawnedSrvIndex
simple string or icon
Gauge32
read-only
Indicates the total number of clients currently connected through prespawned shadows and dispatchers to this database instance, as retrieved from an internal Listener table. When the value of oraSIDCurrentConnectedClients is approaching the value of oraSIDReservedConnections, the number of connection requests to this database instance is reaching the threshold (the reserved number of connections for clients on this database instance).
When the value of oraSIDCurrentConnectedClients equals the value of oraSIDReservedConnections, the incoming connection requests are redirected to dedicated servers. This may not be desirable, as a dedicated server requires more system resources than does a dispatcher or prespawned shadow.
0 - value of oraSIDReservedConnections
very important
oraDispatcherCurrentConnections, oraPrespawnedSrvCurrentConnections
gauge
Counter32
read-only
Indicates the total number of reserved connections for clients through prespawned shadows and dispatchers to this database instance.
0 - 1,000, depending on the number of dispatcher and prespawned shadow processes for the database
very important
oraDispatcherMaximumConnections, oraSIDCurrentConnectedClients
gauge
The oraDedicatedSrvTable contains information about the dedicated servers provided by the managed listener. A dedicated server is a process that executes Oracle server code on behalf of a particular database user process. Monitoring a dedicated server is important in order to ensure that clients seeking access to a database have that opportunity.
Each entry in the oraDedicatedSrvTable represents a dedicated server associated with a current database instance on the managed node. Each entry is indexed first by oraSIDName, and then by oraDedicatedSrvIndex; thus, there can be a one-to-many relationship between a current database instance and the dedicated servers associated with it. By indexing first by oraSIDName, all dedicated servers associated with a given SID can be found using SNMP traversal operations (get-next and get-bulk). The current value of each oraDedicatedSrvTable variable is retrieved from internal listener buffers.
Table B-3 lists the variables included in the oraDedicatedSrvTable.
Variable Name | Object ID |
---|---|
oraDedicatedSrvIndex |
1.3.6.1.4.1.111.5.1.2.1.1 |
oraDedicatedSrvEstablishedConnections |
1.3.6.1.4.1.111.5.1.2.1.2 |
oraDedicatedSrvRejectedConnections |
1.3.6.1.4.1.111.5.1.2.1.3 |
A description of each of these variables follows.
INTEGER (1..2147483647)
read-only
A numeric index, unique among all the dedicated servers, as retrieved from an internal listener table.
1 - 5, depending on the number of database instances for whom this listener listens
very important
oraSIDName
not applicable
Counter32
read-only
Indicates how many incoming connection requests this dedicated server has accepted since startup of this managed listener, as retrieved from an internal listener table.
0 - 4249467295
very important
oraDedicatedSrvRejectedConnections, oraDispatcherRejectedConnections, oraPrespawnedSrvRejectedConnections
counter
Counter32
read-only
Indicates how many incoming connection requests this dedicated server has rejected since startup of this managed listener, as retrieved from an internal listener table.
0 - 4249467295
very important
oraDedicatedSrvEstablishedConnections
counter
The oraDispatcherTable contains information on the dispatchers provided by the managed listener. A dispatcher is an optional background process present only when a multi-threaded server configuration is used. Monitoring a dispatcher is important in order to ensure that clients seeking access to a database have that opportunity.
Each entry in the oraDispatcherTable represents a dispatcher associated with a current database instance. Each entry is indexed first by oraSIDName, and then by oraDispatcherIndex; thus, there can be a one-to-many relationship between a database instance and the dispatcher processes serving it. Using this indexing method, all dispatchers associated with a given SID can be found by SNMP traversal operations (get-next and get-bulk). The current value of most oraDispatcherTable variables is retrieved from internal listener tables.
Table B-4 lists the variables included in the oraDispatcherTable.
A description of each of these variables follows.
INTEGER (1..2147483647)
read-only
A numeric index, unique among all the dispatchers, as retrieved from an internal listener buffer.
1 - 5, depending on the number of dispatchers configured for the database instance
very important
none
not applicable
Counter32
read-only
Indicates how many incoming connection requests this dispatcher has accepted since startup of this managed listener, as retrieved from an internal listener buffer.
When the value of oraDispatcherEstablishedConnections approaches the value of oraDispatcherMaximumConnections, this dispatcher is reaching the threshold (the greatest number of connection requests that can be accepted).
0 - value of oraDispatcherMaximumConnections
very important
oraDedicatedSrvEstablishedConnections, oraDispatcherMaximumConnections, oraDispatcherRejectedConnections, oraPrespawnedSrvEstablishedConnections
counter
Counter32
read-only
Indicates how many incoming connection requests this dispatcher has rejected since startup of this managed listener, as retrieved from an internal listener table.
0 - 4249467295
very important
oraDedicatedSrvEstablishedConnections, oraDispatcherEstablishedConnections, oraDispatcherState, oraPrespawnedSrvEstablishedConnections
counter
Gauge32
read-only
Indicates the number of connection requests this dispatcher is currently redirecting, as retrieved from an internal listener table. Monitoring oraDispatcherCurrentConnections and oraDispatcherMaximumConnections together indicates the load/activity of the dispatcher.
0 - oraDispatcherMaximumConnections
very important
oraSIDCurrentConnectedClients, oraDispatcherMaximumConnections
gauge
INTEGER (1..21474836647)
read-only
Indicates the greatest number of connection requests that this dispatcher can accept, as retrieved from an internal listener table.
0 - value of oraSIDReservedConnections
very important
oraDispatcherCurrentConnections, oraSIDReservedConnections
gauge
INTEGER (1) blocked, or (2) ready.
read-only
Indicates the current state of this dispatcher, as retrieved from an internal listener table. The BLOCKED value (1) indicates that the dispatcher is temporarily not accepting redirected connection requests. The READY value (2) indicates that this dispatcher is ready to accept any redirected connection requests.
enumerated 1 or 2
very important
oraDispatcherRejectedConnections
icon or simple string
DisplayString
read-only
Indicates the protocol for which this dispatcher listens, as well as protocol-specific information, as retrieved from the MTS_LISTENER_ADDRESS parameter of the INIT.ORA configuration file.
1 - 255 characters
important
none
simple string or icon
The oraPrespawnedSrvTable contains information on the prespawned servers provided by the managed listener associated with the current database instance. A prespawned server is an optional shadow process created when the listener is started, and then available for making connections to the database. Prespawned servers reduce connect time by eliminating the need to spawn a shadow for each new connect request. Monitoring a prespawned server is important in order to ensure that clients seeking access to a database have that opportunity.
Each entry in the oraPrespawnedSrvTable represents a prespawned server associated with a current database instance. Each entry is indexed first by oraSIDName, and then by oraPrespawnedSrvIndex; thus, there can be a one-to-many relationship between a database instance and the prespawned servers serving it. Using this indexing method, all prespawned servers associated with a given SID can be found by SNMP traversal operations (get-next and get-bulk). The current value of most oraPrespawnedSrvTable variables is retrieved from internal listener buffers.
Table B-5 lists the variables included in the oraPrespawnedSrvTable.
A description of each of these variables follows.
INTEGER (1..2147483647)
read-only
A numeric index, unique among the prespawned servers configured for this managed listener, as retrieved from an internal listener table.
1 - 1,000, depending on the number of prespawned shadows configured
very important
none
not applicable
Counter32
read-only
Indicates how many incoming connection requests have been accepted by the prespawned server since its startup, as retrieved from an internal listener table.
0 - 4249467295
very important
none
counter
Counter32
read-only
Indicates the number of connection requests this prespawned server has rejected since its startup, as retrieved from an internal listener table. If the value of oraPrespawnedSrvRejectedConnections is creeping up, oraPrespawnedState should be monitored.
0 - 4249467295
very important
oraDedicatedSrvEstablishedConnections, oraPrespawnedSrvEstablishedConnections, oraPrespawnedSrvState
counter
Gauge32
read-only
Indicates how many incoming connection requests currently being redirected by the prespawned server since startup of this managed listener, as retrieved from an internal listener table.
0 - 4249467295
very important
oraPrespawnedSrvMaximumConnections
gauge
INTEGER (1..2147483647)
read-only
Indicates the greatest number of connection requests that this prespawned server can accept. The Listener updates this value in real time.
0 - 1,000, depending on the configuration
very important
oraPrespawnedSrvCurrentConnections
gauge
INTEGER (1) blocked, or (2) ready.
read-only
Indicates the current state of the prespawned server, as retrieved from an internal listener table. The BLOCKED value (1) indicates that the prespawned server is temporarily not accepting redirected connection requests. The READY option (2) indicates that the prespawned server is ready to accept any redirected connection requests.
enumerated 1 or 2
very important
oraPrespawnedSrvRejectedConnection
alarm or icon
DisplayString
read-only
Indicates the protocol on which this prespawned server listens, as well as protocol- specific information. This information is retrieved from an internal Listener table.
1 - 255 characters
important
none
simple string or icon
DisplayString
read-only
Indicates the process ID of the prespawned server, as retrieved from an internal listener table.
1 - 10, depending on the O/S (physical limit is 255 characters)
less important
none
simple string
The oraListenAddressTable contains the addresses on which the listener is listening. These addresses are important to monitor when a Listener cannot come up during startup; these addresses can then be examined for the proper format.
Each entry in the oraListenAddressTable represents an address on which a given active listener is listening. Each entry is indexed first by oraListenerIndex, and then by oraListenAddressIndex; thus, there can be a one-to-many relationship between a listener and the addresses on which it is listening.
Table B-6 lists the variables included in the oraListenAddressTable.
Variable Name | Object ID |
---|---|
oraListenAddressIndex |
1.3.6.1.4.1.111.5.1.6.1.1 |
oraListenAddress |
1.3.6.1.4.1.111.5.1.6.1.2 |
A description of each of these variables follows.
INTEGER (1..2147483647)
read-only
A numeric index, unique among all of the addresses on which the listener is listening, as retrieved from an internal listener table.
1 - 5, depending on configuration
important
oraListenAddress, oraListenIndex
not applicable
DisplayString
read-only
Indicates an address on which this listener is listening, as retrieved from the ADDRESS section of the LISTENER.ORA configuration file.
1 - 255 characters
important
oraListenerIndex
simple string
Table B-7 lists the oraListenerTraps variable.
Variable Name | Object ID |
---|---|
oraListenerStateChange |
1.3.6.1.4.1.111.5.2.1.1.1 |
A description of this variable follows.
{oraListenerState }
Indicates that one of the listeners managed by this agent has changed its listenerState in a way that makes it less accessible for use.
2 (only)
very important
oraListenerState
alarm