Monday, February 10, 2020

ORA-00600, ORA-07445 and ORA-00020 errors and related bugs in 12c (12.2.0.1)


I have come across below error recently in 12c (12.2.0.1). It first started with ORA-00600 followed by ORA-07445 and ORA-00020. The ORA-00600, ORA-07445 looks like real culprit and which lead to ORA-00020 error.

ORA-00600: internal error code, arguments: [17126], [0x0B0D29528], [], [], [], [], [], [], [], [], [], []
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
2020-01-13T23:20:30.493308-08:00
Exception [type: SIGSEGV, Address not mapped to object] [ADDR:0x32000000170] [PC:0x10F9D3FD, kghfnd_in_free_lists()+717] [flags: 0x0, count: 1]
Errors in file /home/oracle/diag/rdbms/ORADB/ORADB/trace/ORADB_ora_62437.trc (incident=41538):
ORA-07445: exception encountered: core dump [kghfnd_in_free_lists()+717] [SIGSEGV] [ADDR:0x32000000170] [PC:0x10F9D3FD] [Address not mapped to object] []
Incident details in: /home/oracle/diag/rdbms/ORADB/ORADB/incident/incdir_41538/ORADB_ora_62437_i41538.trc
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
2020-01-13T23:20:31.182120-08:00
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
2020-01-13T23:20:31.182223-08:00
opidcl aborting process unknown ospid (48392) as a result of ORA-600
……

2020-01-14T01:29:37.222083-08:00
ORA-00020: maximum number of processes (500) exceeded
ORA-20 errors will not be written to the alert log for
the next minute. Please look at trace files to see all
the ORA-20 errors.

After investigation and troubleshooting I found below bugs

1. There is a unpublished bug related to Unified memory KGH related crashes/errors. After discussing with support come to know that particular fix was found on an internal note to already be included in Oracle 12.2.0.1

Bug 30053838
 - LNX-20-ATP: HIT ORA-7445 [KGHFND_IN_FREE_LISTS] AND ORA-600 [KSM_PGA_UM_EXT_FREE:INVALID_EXT_MAGIC], INST CRASH

2. There is a published bug 24596874 and the fix fix for 24596874 is first included in 20.1.0 . Also in term patches may be available for earlier versions.

For bug 24596874 , users notice Memory corruption when CDB environment is setup with star schema on one PDB. Redaction policies enabled on tables/view of the schema and query workload executed with 50 concurrent sessions. Multiple ORA 600 [kghfrh:ds] were seen in the alert log.

So both of the above bugs are ruled out as unpublished bug already part of 12.2.0.1 and published bug is related to Star schema on PDB.

After further investigation with Oracle support found another unpublished Bug 30448845 : DATABASE HANG WITH SIGNATURE: 'PMON TIMER'<='PRIOR SPAWNER CLEAN UP'<='LATCH FREE'<='RELIABLE MESSAGE'

As per Oracle support, this is fixed in 18.1 but the fix is not easy to backports. Oracle suggest to update parameter _pmon_slaves_arr_size=0 as workaround in Oracle 12.2

Users cannot update internal oracle parameters directly in SPFILE, please follow the steps mentioned in the below blog post
https://www.oracleracexpert.com/2020/01/ora-00800-soft-external-error-arguments.html

Note that every environment, errors, load, use cases are different, I would highly recommend users to open a ticket with Oracle support and get confirmation before making any changes to your databases.
Regards
Satishbabu Gunukula, Oracle ACE
http://oracleracexpert.com 

16 comments:

  1. Get Packers and Movers Jaipur List of Top Reliable, 100% Affordable, Verified and Secured Service Provider. Get Free ###Packers and Movers Jaipur Price Quotation instantly and Save Cost and Time. Packers and Movers Jaipur ✔ ✔ ✔ Reviews and Compare Charges for household Shifting, Home/Office Relocation, ***Car Transportation, Pet Relocation, Bike SHifting @ Packers And Movers Jaipur

    ReplyDelete
  2. Packers And Movers Bangalore Local Household Shifting Service, Get Free Best Price Quotes Local Packers and Movers in Bangalore List, Compare Charges, Save Money And Time at
    Local Packers And Movers Bangalore

    ReplyDelete
  3. Really awesome blog!!! I finally found a great post here.I really enjoyed reading this article. It's really a nice experience to read your post. Thanks for sharing your innovative ideas. Excellent work! I will get back here.
    Data Science Course
    Data Science Course in Marathahalli
    Data Science Course Training in Bangalore

    ReplyDelete
  4. Packers and Movers Gurgaon Provide Reliable, Safe and Certified Service Provider list, Get Free ***Best Price Quotaition and Compare Charges. ???Hassle free Household Shifting Services, High Quality packing Material, Office Relocation, Car Transportaion, ###Local and Domestic Shifting Service @
    Packers And Movers Gurgaon

    ReplyDelete
  5. Get Shifting/Relocation Quotation from ###Packers and Movers Delhi. Packers and Movers Delhi 100% Affordable and Reliable ***Household Shifting Services. Compare Transportation Charges and Save Time, Verified and Trusted Packers and Movers in Delhi, Cheap and Safe Local, Domestic House Shifting @
    Packers And Movers Delhi

    ReplyDelete
  6. Very nice article. I enjoyed reading your post. very nice share. I want to twit this to my followers. Thanks ! @ Packers and Movers Ahmedabad

    ReplyDelete
  7. Packers and Movers Pune Provide High Quality ***Household Shifting, Home/Office Relocation, Insurance, Packing, Loading, ###Car Transportation Service Pune and High experiences, Top Rated, Safe and Reliable, Best and Secure Packers and Movers Pune Team List. Get ✔✔✔Affordable Rate Charts and Compare Quotation and Save Money and Time @ Packers And Movers Pune

    ReplyDelete

  8. Thanks for nice blog regarding DevOps. Keep updating
    DevOps Training In Hyderabad

    ReplyDelete
  9. wonderful article. Very interesting to read this article.I would like to thank you for the efforts you had made for writing this awesome article. This article resolved my all queries.
    Data Science Course

    ReplyDelete
  10. Thanks for sharing such a informative blog with us. Keep on sharing
    Azure Training In Hyderabad

    ReplyDelete
  11. Nice Post ! really enjoyed reading this article. Thanks for sharing such detailed information.
    AI Training in Hyderabad

    ReplyDelete
  12. Expected to form you an almost no word to thank you once more with respect to the decent recommendations you've contributed here.
    Machine Learning Training In Hyderabad

    ReplyDelete
  13. Good Article, the information you provided is helpful for me
    Data Science Training In Hyderabad

    ReplyDelete
  14. Nice articles .Thanks for sharing wonderful Articles with us. I am learn more from your articles.
    DevOps Training In Hyderabad

    ReplyDelete