Posts

Showing posts from 2015

Redis user permissions (ACL) and python connection

-
 Recently, I was working on setting up a redis cluster along with separate users for readwrite and readonly. I setup the readonly user using the below privileges (ACLs):   user redisreadonly on >mySuperSecretPassword ~* resetchannels -@all +@read +ping +asking   Once this is setup, I wrote a simple program in python to connect to the redis cluster using the readonly credentials and print the number of keys.   #!/usr/bin/env python3 """ pip3 install redis """ from redis.cluster import RedisCluster, ClusterNode # ─────── Cluster connection ─────── startup_nodes = [ ClusterNode("redis_host_1", 6379), ClusterNode("redis_host_2", 6379), ClusterNode("redis_host_3", 6379) ] rc = RedisCluster(startup_nodes=startup_nodes,decode_responses=True,username='redisreadonly',password='mySuperSecretPassw...
Post a Comment
Read more

Oracle 12c Container views - CDB_ Views

-
Today, I did get an opportunity to research on Containers and pluggable databases - the "single instance, multiple databases" concept that's one of the new features of Oracle 12c. I was really curious to know where the container view data comes from, in other words, where does the data for the CDB_ views come from? Well, this is what I found: It is actually coming from a function: SQL> select name,user,cdb from v$database; NAME USER CDB --------- ------------------------------ --- MY12CDB SYS YES 1 row selected. SQL> select dbms_metadata.get_ddl ('VIEW','CDB_OBJECTS') from dual; DBMS_METADATA.GET_DDL('VIEW','CDB_OBJECTS') -------------------------------------------------------------------------------- CREATE OR REPLACE FORCE NONEDITIONABLE VIEW "SYS"."CDB_OB JECTS" CONTAINER_DATA ("OWNER", "OBJECT_NAME", "SUBO...
Post a Comment
Read more

Is my server physical or virtual?

-
Am I real or virtual? That is the question! That's the realm of philosophy and adhyatma . When and if I put this question to my server, it becomes technical and here's the answer. On Linux # dmidecode | more or dmidecode -s system-manufacturer Sample Output # dmidecode | more # dmidecode 2.9 SMBIOS 2.4 present. 364 structures occupying 17030 bytes. Table at 0x000E0010. Handle 0x0000, DMI type 0, 24 bytes BIOS Information         Vendor: Phoenix Technologies LTD         Version: 6.00         Release Date: 04/14/2014         Address: 0xEA050         Runtime Size: 90032 bytes         ROM Size: 64 kB         Characteristics:                 ISA is supported                 PCI is supported               ...
Post a Comment
Read more

Set Hugepages for Oracle 11gR2 database

-
1. Execute the shell script provided in Note ID: 401749.1 to find out the ideal setting for the parameter vm.nr_hugepages, set it in /etc/sysctl.conf and reboot VM/Server. Script from Note 401749.1 -bash-3.2$ cat huge_pages_calc.sh #!/bin/bash # # hugepages_settings.sh # # Linux bash script to compute values for the # recommended HugePages/HugeTLB configuration # # Note: This script does calculation for all shared memory # segments available when the script is run, no matter it # is an Oracle RDBMS shared memory segment or not. # # This script is provided by Doc ID 401749.1 from My Oracle Support # http://support.oracle.com # Welcome text echo " This script is provided by Doc ID 401749.1 from My Oracle Support (http://support.oracle.com) where it is intended to compute values for the recommended HugePages/HugeTLB configuration for the current shared memory segments. Before proceeding with the execution please note following:  * F...
Post a Comment
Read more

Popular posts from this blog

Interesting Oracle Applications (EBS) Interview Questions

-
Below are some interesting interview questions that I have faced over the years. What is the difference between a concurrent manager and a cron job? Can one patch a CRS Oracle home with the CRS services up? Suppose, there are 2 nodes node1 and node2 with CRS cluster and one wants to patch node1. Can it be done with node2 being up? Suppose one fires a select statement and the data does not in the library cache, then the data, obviously, has to be fetched from the data files. Which background process is used for this purpose? What are the sizing requirements for say, a 100 concurrent users Oracle Apps Installation? What is the difference between a shared appl_top and a staged appl_top?
Read more

Modify retention period of workflow queues

-
Yesterday, there was a requirement to increase the retention period of WF_DEFERRED and WF_BPEL_Q so that the developers could troubleshoot issues involving business events. This can be done this way: 1. Check the retention period of existing workqueues. SQL> SELECT owner, name, retention FROM all_queues WHERE name LIKE 'WF%'; OWNER           NAME                                                RETENTION --------------- --------------------------------------------- ------------------------------ APPS                 WF_BPEL_Q                                                0 APPLSYS         WF_INBOUND_QUEUE              ...
Read more

Check if UTL_FILE and FND_FILE are working fine

-
Yesterday, while troubleshooting a vexing ORA-29280 error, I came across 2 useful PL/SQL anonymous blocks that can be used to test FND_FILE and UTL_FILE to find out whether they are indeed working fine. UTL_FILE set serveroutput on DECLARE file_location VARCHAR2(256) := '<first entry on utl_file_dir>'; file_name VARCHAR2(256) := 'utlfile1.lst'; file_text VARCHAR2(256) := 'THIS IS A TEST'; file_id UTL_FILE.file_type; BEGIN file_id := UTL_FILE.fopen(file_Location, file_name, 'W'); UTL_FILE.put_line(file_id, file_text); UTL_FILE.fclose(file_id); EXCEPTION WHEN UTL_FILE.INVALID_PATH THEN dbms_output.put_line('Invalid path ' || SQLERRM); WHEN OTHERS THEN dbms_output.put_line('Others '|| SQLCODE || ' ' || SQLERRM); END; / References: Metalink (MOS) Note ID: 261693.1 FND_FILE set serveroutput on exec FND_FILE.PUT_LINE(FND_FILE.LOG, 'THIS IS A TEST'); HTH....
Read more