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oracle listener confusion

user521233 Newbie
Currently Being Moderated
sorry but i'm a bit of a noob with database administration.

i have a windows 7 box with an oracle 11g database. i was wanting to create a new listener to listen for requests on the machines ip address. traditionally the database is down and i go into windows services and start the database and listener from there.

i created new listener using Oracle Net Configuration Assistant and noticed in the windows services list. then i deleted it using the same tool.

i created a new listener using Oracle Enterprise Manager, did not notice it in the windows services list but understand that it is dynamically created? either way... i deleted it.

now, the funny thing is that i have a second listener in windows services list. i'm unable to see it using Oracle Net Configuration Assistant. the ususal listener in that list is started. Oracle Enterprise Manager only sees one listener and is unable to start it. i'm able to connect to the database using sqlplus.

i'm a little confused...

can i delete the listener that i can't start in Oracle Enterprise Manager to see if it rids me of the extra listener in the windows services list? why can't OEM see the started listener from the windows services list?

thanks for any direction in the matter.
  • 1. Re: oracle listener confusion
    sb92075 Guru
    Currently Being Moderated
    user521233 wrote:
    sorry but i'm a bit of a noob with database administration.

    i have a windows 7 box with an oracle 11g database. i was wanting to create a new listener to listen for requests on the machines ip address. traditionally the database is down and i go into windows services and start the database and listener from there.

    i created new listener using Oracle Net Configuration Assistant and noticed in the windows services list. then i deleted it using the same tool.

    i created a new listener using Oracle Enterprise Manager, did not notice it in the windows services list but understand that it is dynamically created? either way... i deleted it.

    now, the funny thing is that i have a second listener in windows services list. i'm unable to see it using Oracle Net Configuration Assistant. the ususal listener in that list is started. Oracle Enterprise Manager only sees one listener and is unable to start it. i'm able to connect to the database using sqlplus.

    i'm a little confused...

    can i delete the listener that i can't start in Oracle Enterprise Manager to see if it rids me of the extra listener in the windows services list? why can't OEM see the started listener from the windows services list?

    thanks for any direction in the matter.
    Single listener can support multiple instances in multiple ORACLE_HOME & even multiple IP# & ports.

    OEM requires a functioning listener to connect to the DB.

    Consider to stop messing with things you don't understand.
  • 2. Re: oracle listener confusion
    user521233 Newbie
    Currently Being Moderated
    its my biggest peeve when people respond yet provide nothing helpful.
  • 3. Re: oracle listener confusion
    sb92075 Guru
    Currently Being Moderated
    user521233 wrote:
    its my biggest peeve when people respond yet provide nothing helpful.
    My biggest peeve are folks who too lazy & inconsiderate to mark threads as answered.

    Handle:     user521233
    Status Level:     Newbie
    Registered:     Jul 20, 2006
    Total Posts:     175
    Total Questions:     55 (35 unresolved)

    The challenge is that only you know what really exists on your system now.
    We don't know which OS services actually exist or not.
    We don't know which listener actually exist or not.
    We don't know what has been configured or mis-configured.

    We know you have a problem & that we have no actual specific & actual clues to base any recommendation.
  • 4. Re: oracle listener confusion
    user521233 Newbie
    Currently Being Moderated
    if i haven't marked previous questions as answered its because... THEY WEREN'T ANSWERED!

    and i would prefer that you only respond if you are willing to assist me. do you realize that once threads have responses then many forum members will assume that someone is getting assistance and will thus not even bother to read the submission? did you imagine that i would mark this thread as ANSWERED after your response?

    i've given the specifics of what i know about my situation. i've seen plenty of other posts where people assist someone who is far more clued out then i... if you aren't interested in assisting me then.... PLEASE, move on!
  • 5. Re: oracle listener confusion
    Aman.... Oracle ACE
    Currently Being Moderated
    Do you have a listener.ora created in the database home? If yes, can you post it please?

    Aman....
  • 6. Re: oracle listener confusion
    user521233 Newbie
    Currently Being Moderated
    thanks aman... this is the listener.ora file i have in the oracle home:

    # listener.ora Network Configuration File: C:\oracle11g\product\11.2.0\dbhome_1\network\admin\listener.ora
    # Generated by Oracle configuration tools.

    SID_LIST_LISTENER =
    (SID_LIST =
    (SID_DESC =
    (SID_NAME = CLRExtProc)
    (ORACLE_HOME = C:\oracle11g\product\11.2.0\dbhome_1)
    (PROGRAM = extproc)
    (ENVS = "EXTPROC_DLLS=ONLY:C:\oracle11g\product\11.2.0\dbhome_1\bin\oraclr11.dll")
    )
    )

    LISTENER =
    (DESCRIPTION_LIST =
    (DESCRIPTION =
    (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
    )

    ADR_BASE_LISTENER = C:\oracle11g

    additionally, if i run "lsnrctl status" i get a running listener that is using a different parameter file that looks like this:

    # listener.ora Network Configuration File: C:\nexus6\tnsnames backup\listener.ora
    # Generated by Oracle configuration tools.

    SID_LIST_LISTENER_EXTERNAL =
    (SID_LIST =
    (SID_DESC =
    (SID_NAME = CLRExtProc)
    (ORACLE_HOME = C:\oracle11g\product\11.2.0\dbhome_1)
    (PROGRAM = extproc)
    (ENVS = "EXTPROC_DLLS=ONLY:C:\oracle11g\product\11.2.0\dbhome_1\bin\oraclr11.dll")
    )
    )

    its not intuitive to me that the OEM doesn't list the listener that its obviously using to connect to the database? additionally the OEM is identifying numerous policy violations of the listener it does list that i'm unable to start... if thats of any interest.

    again, i'd just like to get the OEM showing nicely and the errant listener in the services list removed.
  • 7. Re: oracle listener confusion
    BillyVerreynne Oracle ACE
    Currently Being Moderated
    Not sure why you want multiple listeners on the same server. Does not make much sense.

    An Oracle Listener is based on the same principle as that of inetd (internet service daemon). Inetd serves as network listener for a wide range of network services (finger, whois, echo, chargen, svn, etc).

    Instead of each of these services using its own listener process (using the very same code and principles on different listener ports in different processes), and having a large number of listener processes (for services that can be very seldom used), the Inetd is the "super listener daemon" that listens on behalf of that service.


    Likewise, the Oracle Listener listens for tcp connections (on different ports and IP addresses) for database services. An instance will register itself dynamically with the listener and inform it of the services it has.

    No need for multiple listeners - as this seldom make any sense. No need for a complex listener.ora file. It can be empty (defaults will be used and usually suffices). It should contain only the basics such as specific ports and IPs to listen on, app protocols to support (e.g. WebDAV/http in addition to OCI), and security settings (e.g. preventing unauthorised access to the listener).
  • 8. Re: oracle listener confusion
    user521233 Newbie
    Currently Being Moderated
    thanks for the information, billy... i am endeavoring to get to a single listener situation.

    i have two listener.ora files as i've defined above. i have realized that by setting the tns_admin evironment variable between the two listener.ora locations that i get different outcomes from Oracle Net Manager, OEM Database Control and lsnrctl.

    so, if i set tns_admin to "C:\nexus6\tnsnames backup" and windows service listener is started then:
    1) Oracle Net Manager sees no local listener configurations
    2) OEM Database Control sees a listener that is down (and no Related Links are displayed? unable to access Net Services Administration page?)
    3) "lsnrctl status" shows the listener defined in "C:\nexus6\tnsnames backup\listener.ora" as up
    4) database is connectable.

    if i set tns_admin to "C:\oracle11g\product\11.2.0\dbhome_1\NETWORK\ADMIN" and windows service listener is started then:
    1) Oracle Net Manager sees a listener configuration
    2) OEM Database Control sees a listener that is up
    3) "lsnrctl status" shows no listener
    4) database is connectable.

    if the windows service listener is not started then:
    1) Oracle Net Manager sees a listener configuration
    2) OEM Database Control sees nothing
    3) "lsnrctl status" shows no listener
    4) database is not connectable.

    so obviously the windows service listener is critical and that its not configurable by OEM Database Control or Oracle Net Manager?

    i have an extra windows service listener for some reason and i see from other posts that i can manually delete that from the windows registry. but could this be the service that OEM Database is looking at that is not up?

    the whole point of this excercise was to the get the database listening on the machines ip address and not just localhost.

    any information i could use to clean this up would be most welcome.

    Edited by: user521233 on Nov 21, 2012 11:30 AM

    Edited by: user521233 on Nov 21, 2012 11:36 AM
  • 9. Re: oracle listener confusion
    sb92075 Guru
    Currently Being Moderated
    user521233 wrote:

    the whole point of this excercise was to the get the database listening on the machines ip address and not just localhost.
    this is done at OS level & has NOTHING to do with Oracle or the listener.
  • 10. Re: oracle listener confusion
    user521233 Newbie
    Currently Being Moderated
    thanks for your input, sb92075.
  • 11. Re: oracle listener confusion
    sb92075 Guru
    Currently Being Moderated
    user521233 wrote:
    thanks for your input, sb92075.
    Listener just use what the OS provides.
  • 12. Re: oracle listener confusion
    user521233 Newbie
    Currently Being Moderated
    do you suggest that i simply leave my configuration at situation 2 above then, sb92075? with tns_admin set to "C:\oracle11g\product\11.2.0\dbhome_1\NETWORK\ADMIN"?

    is it best to remove any entries in the listener.ora files that i have (if it wasn't clear, this is simply a workstation and has no external facilities accessing it)?
  • 13. Re: oracle listener confusion
    sb92075 Guru
    Currently Being Moderated
    user521233 wrote:
    do you suggest that i simply leave my configuration at situation 2 above then, sb92075? with tns_admin set to "C:\oracle11g\product\11.2.0\dbhome_1\NETWORK\ADMIN"?

    is it best to remove any entries in the listener.ora files that i have (if it wasn't clear, this is simply a workstation and has no external facilities accessing it)?
    since V10 no listener.ora file is required to start or use the listener.

    Consider to move or rename listener.ora before starting the listener after a reboot.

    the post COMPLETE results from command below

    lsnrctl status
  • 14. Re: oracle listener confusion
    user521233 Newbie
    Currently Being Moderated
    Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
    STATUS of the LISTENER
    ------------------------
    Alias LISTENER
    Version TNSLSNR for 64-bit Windows: Version 11.2.0.1.0 - Production
    Start Date 21-NOV-2012 12:04:16
    Uptime 0 days 0 hr. 0 min. 31 sec
    Trace Level off
    Security ON: Local OS Authentication
    SNMP OFF
    Listener Log File c:\oracle11g\diag\tnslsnr\nexus6\listener\alert\log.xml
    Listening Endpoints Summary...
    (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=nexus6)(PORT=1521)))
    The listener supports no services
    The command completed successfully

    that seems really promising now and the results from looking at OEM Database Control and Oracle Net Manager are starting to make sense to me. correct me if i'm wrong but all that shows up in the OEM DB Net Services Administration and the Oracle Net Manager is stuff from the listener.ora file... which has not much to do with the os level listener service. that was really confusing me.

    i additionally removed the errant os service listener without any negative impact.
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