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AskDba.org Weblog » Entries tagged with "Hangs"

Connections to DataBase Hang Including “/ as sysdba”

April 7th, 2009 | 2 Comments

Recently I faced one issue where all the connection to database hung and it was also not possible to login to database using “/ as sysdba”. To get access of sqlplus I used the following syntax: $ sqlplus -prelim / as sysdba With “prelim” option we can run some commands which will help in collection useful information about the problem. This will work only in Oracle 10g and higher version. After successfully getting connected run the following commands to generate Hanganalyze and systemstate traces: SQL> oradebug setmypid SQL> oradebug unlimit SQL> oradebug dump systemstate 266 SQL> oradebug tracefile_name – This will give you the name of the tracefile generated. SQL > oradebug dump hanganalyze 2 SQL > oradebug tracefile_name To analyze these trace files one should be aware of Metalink Note: 215858.1. After analyzing these files I found that following event was active and … Read entire article »

Filed under: oracle, performance

Resolving Shutdown Immediate Hang Situations

May 26th, 2008 | 5 Comments

Many times Oracle DBA’s are faced with a situation where shutting down the instance with shutdown immediate seems to take infinite time and gives a impression that the session is hung. In most of the cases this is not a hang. Hang can be defined as a scenario when few sessions/processes are waiting on some action and in turn blocking other session/processes to complete their tasks. Now the original sessions could be waiting because of resource issues or Oracle Bugs. Shutdown immediate can take long time to complete (appear to be hung) because of three reasons: 1. Uncommitted transactions are being rolled back. 2. SMON is cleaning temp segments or performing delayed block cleanouts. 3. Processes still continue to be connected to the database and do not terminate. 1. Uncommitted transactions are being rolled back: This … Read entire article »

Filed under: Featured, database, oracle

Diagnostics For Database Hang

March 21st, 2008 | 4 Comments

Many times Oracle DBA’s are in a situation when the database is hung and does not seem to be responding. In some scenarios, state is such that you cannot even connect to the sqlplus session. Majority people restart the database (Sometimes I wonder if this is due to the fact that most of us started working on Computer’s on Microsoft Windows ) and then log a ticket with Oracle support . They inturn happily inform us that “They do not have any diagnostic information to diagnose and resolve the issue and we need to wait for next occurrence to collect some diagnostic information) Based on my experiences , I am writing this article to assist my fellow Oracle DBA’s to diagnose the problem and collect the required information. So … Read entire article »

Filed under: performance