Try to be more clear, I'm in lack of ideas in this problem, even it sounds like a classic.
My application is running on weblogic 10.3.3 application server, and for database I am using Oracle database 11g. My problem is that there is table in db, let's say "user.", there is column, let's say "columnA", in this table. This table is updating by some module of application.
What I want if when value of column is "abc.", then I have to show alert to console(IP). {IP can be retrieved from DB as it is configured in DB. this ip will be other linux system other than linux machine where oracle database is installed.} Updating is continuously done on my table from module of application. Please tell me from where should I start?, what should I read. I am not able to understand what should be approach. Any help is much appreciated.
A trigger on the table can call UTL_HTTP to communicate with another machine (eg call a RESTful API).
The architectural questions are :
This will happen PRIOR to the commit so you may get false alerts if a change is rolled back
If you wait for a response, it will slow the system down.
What do you do if you get an non-standard response (eg the other server isn't available)
Related
currently, we are using oracle 8i and we are working to decommisson it.
I need to find out which all other databases are connecting to our database using db link.
Please note, I am not looking for the connection from our database to others database. I already got that information using all_Db_links.
If you audit connections to the database or look at the listener log, that will tell you the machines that are connecting to the database and the application that is connecting (that information is coming from the client so it could be spoofed but I'm assuming no one is actively trying to hide information from you). That should allow you to determine which connections are coming via database links. That may not tell you which database on the particular server is connecting if there are multiple databases on the same server using the same Oracle Home. But it should narrow it down to a relatively small number of databases that you can manually check.
I have to deal with the following scenario for spring application with Oracle database:
Spring application uses the primary database. In the meantime the secondary database stores data for disaster recovery (from primary).
The first step is currently provided. At this moment I have to implement:
When the primary database gets offline application should change the connection to the secondary database).
The implementation should be programmatically. How can I achieve that without changing the code that currently exists? Is there any working solution (library)?
I think about AbstractRoutingDataSource and ping databases (e.g. every 5 seconds) but I'm not sure about this solution.
So, let's to summarize the issue. I was unable to use Oracle RAC (Real Application Cluster). If the implementation should be programmatically you can try AbstractRoutingDataSource approche.
I have implemented timer that pings current database every 1 second (you can use validation query and check if you can read from database... if no we assume there is no connection and we can switch a datasource).
Thanks to that I was able to change datasource on runtime when current datasource is offline. What is more important it was automatic.
On the other hand, there are disadvantages:
For short time user can see the errors if the database is not
switched yet.
Some part of application may stop working if it is not properly
secured against the lack of connection to the database.
I support an application whose UI is built on weblogic server. I need to know the sql query fired in the database whenever any action is performed on UI. Since there a lot of users hence I need to know is there any specific action through which I can identify it ?
Your managed server logs should give you queries run through a PreparedStatement. Any database will give you auditing capabilities so you can track what SQL was run, origins and parameters passed.
My delayed job has something to do with exporting slightly edited version of most of the tables in the app's database, and while doing so, it is critical that none of the current data is being edited.
Is it possible to lock the entire database while running this delayed job?
More Information:
The database to be exported is in PostgreSQL, Heroku's postgresql database, to be more specific.
The flow is something like (all below should be done automatically by the code):
site would be put in maintenance mode,
freeze then export the database, then
when exporting is complete, re-activate the site back
Given there is not a lot of information with your question, I am going to answer you as best I can.
1) What is the database type and model? Is it a standalone DB like MS Access or Informix SE?
2) If not a standalone engine, does this database support replication. I used to work a lot with MS SQL Server, and replication had implications while the database was live and being edited. That is the implications were whether edited data was replicated. In this case, consult the docs. Is it an option to use replication to preserve the current database?
3) What kind of task is this? It sounds like maintenance. Our Informix SE databases lock when being imported or exported. On the production server, it is my job to make sure no local server applications are trying to access the locked DB, and that our external payments web site cannot interfere while the db is locked.
4) If this is a production site that is not in maintenance mode, then I suggest you probably do not want to lock an entire database.
I am sorry for not answering your question directly, but more information is needed like are you asking if this can be done from the Ruby DB interface on some model of db.
My team inherited an Oracle-based web application and they are fairly inexperienced with Oracle database servers.
The Oracle 10g server is running on a Windows 2003 Server with plenty of disk space and from time to time, all connectivity is lost, the application stops working, not even SQL Plus is able to connect to the database server.
But when we check the Windows Service manager, it says that the service is up and running. A restart usually fixes the problem, but we need to properly troubleshoot it so we know what's causing it and so we can avoid it to happen anymore.
Where should we start looking for clues? What are the criticial log files we should be investigating?
On the server you should have an environment variable called ORACLE_HOME which indicate the root of the Oracle install. Most likely the Oracle trace/dump folders will be under there. Search for a folder called "bdump" (background dump). That's where the main log file, knows as the alert log, will be, as well as trace files generated by background processes. There will be an adjacent file called "udump" which will contain any trace files generated by user processes.
However, my real advice is that you should either hire someone who knows Oracle or get Oracle Support involved.
The alert log would be the first file to check.
It will probably be in $ORACLE_HOME/admin/bdump and (probably) called alert_DATABASE-SID.log
It contains most of the important actions that the database does, as well as any important errors that occur.
I have to agree with cagcowboy. Check your alert logs for errors. If no errors then maintain a sysdba login into the database and when it hangs, attempt to do a hang analysis. See metalink note 215858.1 on hanganalyze.
Have you tried tnsping? We've occasionally run into problems with the listener that requires an assist from our DBA. tnsping is the diagnostic tool we use to do triage.
I would recommend hiring an experienced Oracle DBA if at all possible.
check the alert log to see how the Db is structured. sometimes badly set parameters make hangs or slow performance. or you can shutdown and start in mount mode, then check the v$parameter values for problems. setting total memory is very important.