Thursday, February 2, 2012
-- Big Data - Don't miss this event --
http://www.oracle.com/us/dm/43327-wwmk11095162mpp003c004-oem-1495099.html
Wednesday, January 18, 2012
-- Fundamental Oracle flaw revealed --
Very interesting InfoWorld article worth to share, please be sure you apply the latest January 2012 CPU patch. You can access the article by clicking here.
Friday, March 25, 2011
- Oracle 11g Automatic Memory Management (AMM) --
Let's start with a brief introduction to basic concepts.
PROGRAM GLOBAL AREA (PGA): is a region that contains data and control information for a server process, this is non shared memory created by the database when a server process is started and access is exclusive to the particular server process.SH
SHARED_GLOBAL_AREA (SGA) : Is a group of memory structures that contain data and control information for the Oracle instance, it is shared by all background processes.
Oracle has made great progress to simplify memory management through the last versions of the RDBMS. In 9i they introduced PGA management, in 10g they automated the SGA management and in 11g you can manage both (PGA and SGA) with a single configuration using "Automatic Memory Management (AMM)". AMM allows you to allocate a chunk of memory which Oracle uses to manage both SGA and PGA, AMM uses 2 parameters:
MEMORY_TARGET: Amount of memory available to Oracle to use dynamically to control SGA and PGA, this is the amount of memory Oracle will allocate when you start the database to manage PGA and SGA.
MEMORY_MAX_TARGET: Maximum amount of memory that Oracle can use, when no specified the max is equal to MEMORY_TARGET.
When AMM is in use, SGA_TARGET (Introduced in 10g) and PGA_AGGREGATE_TARGET (Introduced in 9i) act as the minimum size setting for their respective areas. It is recommend to set this to 0 when using AMM so Oracle can take full control of it.
PROGRAM GLOBAL AREA (PGA): is a region that contains data and control information for a server process, this is non shared memory created by the database when a server process is started and access is exclusive to the particular server process.SH
SHARED_GLOBAL_AREA (SGA) : Is a group of memory structures that contain data and control information for the Oracle instance, it is shared by all background processes.
Oracle has made great progress to simplify memory management through the last versions of the RDBMS. In 9i they introduced PGA management, in 10g they automated the SGA management and in 11g you can manage both (PGA and SGA) with a single configuration using "Automatic Memory Management (AMM)". AMM allows you to allocate a chunk of memory which Oracle uses to manage both SGA and PGA, AMM uses 2 parameters:
MEMORY_TARGET: Amount of memory available to Oracle to use dynamically to control SGA and PGA, this is the amount of memory Oracle will allocate when you start the database to manage PGA and SGA.
MEMORY_MAX_TARGET: Maximum amount of memory that Oracle can use, when no specified the max is equal to MEMORY_TARGET.
When AMM is in use, SGA_TARGET (Introduced in 10g) and PGA_AGGREGATE_TARGET (Introduced in 9i) act as the minimum size setting for their respective areas. It is recommend to set this to 0 when using AMM so Oracle can take full control of it.
Thursday, March 3, 2011
-- How to map disk devices to physical devices in Solaris --
You can map between the two device naming conventions using a script like the one below.
Instance Names: Instance names refer to the nth device in the system (for example, sd20).
Instance names are occasionally reported in driver error messages. You can determine the binding of an instance name to a physical name by looking at dmesg(1M) output, as in the following example.
sd9 at esp2: target 1 lun 1 sd9 is /sbus@1,f8000000/esp@0,800000/sd@1,0
Once the instance name has been assigned to a device, it remains bound to that device.
Instance numbers are encoded in a device's minor number. To keep instance numbers consistent across reboots, the system records them in the /etc/path_to_inst file.
!/usr/bin/env perl
use strict;
my @path_to_inst = qx#cat /etc/path_to_inst#;
map {s/"//g} @path_to_inst;
my ($device, $path, @instances);
for my $line (qx#ls -l /dev/dsk/*s2#) {
($device, $path) = (split(/\s+/, $line))[-3, -1];
$path =~ s#.*/devices(.*):c#$1#;
@instances =
map {join("", (split /\s+/)[-1, -2])}
grep {/$path/} @path_to_inst;
*emphasized text*
for my $instance (@instances) {
print "$device $instance\n";
}
}
Instance Names: Instance names refer to the nth device in the system (for example, sd20).
Instance names are occasionally reported in driver error messages. You can determine the binding of an instance name to a physical name by looking at dmesg(1M) output, as in the following example.
sd9 at esp2: target 1 lun 1 sd9 is /sbus@1,f8000000/esp@0,800000/sd@1,0
Once the instance name has been assigned to a device, it remains bound to that device.
Instance numbers are encoded in a device's minor number. To keep instance numbers consistent across reboots, the system records them in the /etc/path_to_inst file.
!/usr/bin/env perl
use strict;
my @path_to_inst = qx#cat /etc/path_to_inst#;
map {s/"//g} @path_to_inst;
my ($device, $path, @instances);
for my $line (qx#ls -l /dev/dsk/*s2#) {
($device, $path) = (split(/\s+/, $line))[-3, -1];
$path =~ s#.*/devices(.*):c#$1#;
@instances =
map {join("", (split /\s+/)[-1, -2])}
grep {/$path/} @path_to_inst;
*emphasized text*
for my $instance (@instances) {
print "$device $instance\n";
}
}
Tuesday, February 15, 2011
-- Oracle TAF server side not properly configured using srvctl due to bug 6886239 --
Oracle alerted us recently of a non public bug #6886239 "DBMS_SERVICE parameters are not added using srvctl add service. It affects 10g and 11gR1 databases, this is fixed in release 11.2 onwards. In Oracle RAC after setting up TAF although it does not fails and everything looks good, it does not configure correctly.
When you check the service configuration you find no values for failover method, type and retries, those values are needed for TAF to happen.
Creating a service
srvctl add service -d rac -s server_taf -r "rac1,rac2" -P BASIC
Start the service
srvctl start service -d rac -s server_taf
Checking that the services are running.
srvctl config service -d rac
ractest PREF: rac1 rac2 AVAIL:
server_taf PREF: rac1 rac2 AVAIL:
Getting the service ID value
sqlplus /nolog
Connect / as sysdba
SQL> select name,service_id from dba_services where name = 'server_taf';
NAME SERVICE_ID
---------------------------------------------------------------- ----------
server_taf 6
Checking the setup
SQL>col name format a15
col failover_method format a11 heading 'METHOD'
col failover_type format a10 heading 'TYPE'
col failover_retries format 9999999 heading 'RETRIES'
col goal format a10
col clb_goal format a8
col AQ_HA_NOTIFICATIONS format a5 heading 'AQNOT'
SQL>select name, failover_method, failover_type, failover_retries,goal, clb_goal,aq_ha_notifications
from dba_services where service_id = 6
NAME METHOD TYPE RETRIES GOAL CLB_GOAL AQNOT
--------------- ----------- ---------- -------- ---------- -------- -----
server_taf LONG NO
Adding the server side failover parameter to the service
Server side TAF method is BASIC. BASIC is the only value currently supported. This means that a new connection is established at failure time. It is not possible to pre-establish a backup connection. (which is to say, PRECONNECT is not supported)
SQL> execute dbms_service.modify_service (service_name => 'server_taf' -
, aq_ha_notifications => true -
, failover_method => dbms_service.failover_method_basic -
, failover_type => dbms_service.failover_type_select -
, failover_retries => 180 -
, failover_delay => 5 -
, clb_goal => dbms_service.clb_goal_long);
PL/SQL procedure successfully completed.
Check that the service can now see the values for methods, types and retries
SQL>select name, failover_method, failover_type, failover_retries,goal, clb_goal,aq_ha_notifications
from dba_services where service_id = 6
NAME METHOD TYPE RETRIES GOAL CLB_GOAL AQNOT
--------------- ----------- ---------- -------- ---------- -------- -----
server_taf BASIC SELECT 180 NONE LONG YES
Check that the listener has the service registered
lsnrctl services
Create a net service name. Here we have client load balancing between the two nodes.
SERVERTAF =
(DESCRIPTION =
(LOAD_BALANCE = yes)
(ADDRESS = (PROTOCOL = TCP)(HOST = dell01)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = dell02)(PORT = 1521))
(CONNECT_DATA =
(SERVICE_NAME = server_taf.za.oracle.com)
You are all set now :-
When you check the service configuration you find no values for failover method, type and retries, those values are needed for TAF to happen.
Creating a service
srvctl add service -d rac -s server_taf -r "rac1,rac2" -P BASIC
Start the service
srvctl start service -d rac -s server_taf
Checking that the services are running.
srvctl config service -d rac
ractest PREF: rac1 rac2 AVAIL:
server_taf PREF: rac1 rac2 AVAIL:
Getting the service ID value
sqlplus /nolog
Connect / as sysdba
SQL> select name,service_id from dba_services where name = 'server_taf';
NAME SERVICE_ID
---------------------------------------------------------------- ----------
server_taf 6
Checking the setup
SQL>col name format a15
col failover_method format a11 heading 'METHOD'
col failover_type format a10 heading 'TYPE'
col failover_retries format 9999999 heading 'RETRIES'
col goal format a10
col clb_goal format a8
col AQ_HA_NOTIFICATIONS format a5 heading 'AQNOT'
SQL>select name, failover_method, failover_type, failover_retries,goal, clb_goal,aq_ha_notifications
from dba_services where service_id = 6
NAME METHOD TYPE RETRIES GOAL CLB_GOAL AQNOT
--------------- ----------- ---------- -------- ---------- -------- -----
server_taf LONG NO
Adding the server side failover parameter to the service
Server side TAF method is BASIC. BASIC is the only value currently supported. This means that a new connection is established at failure time. It is not possible to pre-establish a backup connection. (which is to say, PRECONNECT is not supported)
SQL> execute dbms_service.modify_service (service_name => 'server_taf' -
, aq_ha_notifications => true -
, failover_method => dbms_service.failover_method_basic -
, failover_type => dbms_service.failover_type_select -
, failover_retries => 180 -
, failover_delay => 5 -
, clb_goal => dbms_service.clb_goal_long);
PL/SQL procedure successfully completed.
Check that the service can now see the values for methods, types and retries
SQL>select name, failover_method, failover_type, failover_retries,goal, clb_goal,aq_ha_notifications
from dba_services where service_id = 6
NAME METHOD TYPE RETRIES GOAL CLB_GOAL AQNOT
--------------- ----------- ---------- -------- ---------- -------- -----
server_taf BASIC SELECT 180 NONE LONG YES
Check that the listener has the service registered
lsnrctl services
Create a net service name. Here we have client load balancing between the two nodes.
SERVERTAF =
(DESCRIPTION =
(LOAD_BALANCE = yes)
(ADDRESS = (PROTOCOL = TCP)(HOST = dell01)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = dell02)(PORT = 1521))
(CONNECT_DATA =
(SERVICE_NAME = server_taf.za.oracle.com)
You are all set now :-
Tuesday, October 19, 2010
-- Questions about the Oracle GG Roadmap --
By Oracle Corp.
We now support the recyclebin on/true for Oracle 11g along with our DDL replication support, Oracle 10g still requires the recyclebin to be off/false.
2.- Does OGG support active-active in a 3+ node (multi master) configuration? Documentation shows 3 nodes in an active-active configuration, is 3+ supported? If so, any restrictions for DML or DDL for a 3+ active-active configuration?
1.- Will Oracle fix the recyclebin off issue when capturing DDL? If so, what OGG release and what RDBMS versions are expected to support a functioning recyclebin in the source?
We now support the recyclebin on/true for Oracle 11g along with our DDL replication support, Oracle 10g still requires the recyclebin to be off/false.
2.- Does OGG support active-active in a 3+ node (multi master) configuration? Documentation shows 3 nodes in an active-active configuration, is 3+ supported? If so, any restrictions for DML or DDL for a 3+ active-active configuration?
Our active-active capabilities apply to any number of nodes in the configuration, in other words, we are not limited to only two. Obviously you need to make special considerations for other factors such as the replication of tables that use sequences, replication of truncate or other DDL operations, for example. For best practices, I recommend for multi-node active-active environments, that user privileges/grants are set so that DDL operations can only originate from one node and not the others. Configure OGG to replicat those DDL operations to all downstream nodes in one direction only. Of course that means that other considerations need to plan in event that the node that allows DDL operations goes down or has a planned downtime for maintenance activities.
·
3.- When will OGG support source tables with Advanced Compression? 10.4.x docs says compressed tables are not supported for extract.
It is on the road-map to support advanced compression. In fact, a release defining feature is to integrate our transaction log reading functionality with the XStreamOut API. This integration will give us support for the variety of database compression features. This is scheduled to be part of the next major release.
4.- Will the SUPPRESSTRIGGERS param available for RDBMS 10.2.0.5 and 11.2.+ for OGG 11.1.x be supported in other RDBMS versions, mainly 10.2.0.4 and all 11G R1 RDBMS versions.
SUPPRESSTRIGGERS parameter support is the ultimate goal, but I am not clear which future release this is targeted to be included. Each database has different functionality so it might be a phased approach depending if it is possible and the development effort required to support it.
-- CRS will not start on one node (Fixed on 11.2.0.2 and Workaround below) --
Abstract: CORE DUMP OF OCSSD.BIN WHEN VOTING DISK IS NOT ACTIVATED.
Some explanation from development:
==================================
In 11.2, voting files are discovered, not hard-wired, so we look through a
list of files that are specified in the 'discovery string', e.g.
/dev/vdisk/*, and use all files that appear to be legitimate voting files,
i.e. they have a TOC (Table Of Contents), volume info block, etc. Since the
VG with the voting files is not online, the discovery does not see them at
all, so does not consider them as voting files and fails as a result of an
inability to find enough voting files.
=====================================
The workaround is to wait the disks are completely ONLINE after machine boot before cluster is started
(note 459169.1 CRS Does Not Startup Automatically After Node Reboot,
Manual Start is OK - but this node is up to 11.1 version)
or apply patch, backport is available for Solaris x86-64(64 bit) - please confirm the Operating System
please upload the patch inventory - I may need to raise backport for you
We're getting these errors on the other node when rebooting:
I did see in the boot messages on both hosts these items:
Johnston, Nathaniel [10:39 AM]:
Sep 24 16:05:15 mhddb-nb-2p.philadelphia.pa.bo.comcast.net root: Oracle HA daemon is enabled for autostart.
Johnston, Nathaniel [10:39 AM]:
Sep 24 16:05:18 mhddb-nb-2p.philadelphia.pa.bo.comcast.net unix: vn_rdwr failed with error 0x15
Sep 24 16:05:18 mhddb-nb-2p.philadelphia.pa.bo.comcast.net unix: kobj_load_module: read header failed
Johnston, Nathaniel [10:39 AM]:
Sep 24 16:05:19 mhddb-nb-2p.philadelphia.pa.bo.comcast.net root: exec /u01/app/grid/perl/bin/perl -I/u01/app/grid/perl/lib /u01/app/grid/bin/crswrapexece.pl /u01/app/grid/crs/install/s_crsconfig_mhddb-nb-2p_env.txt /u01/app/grid/bin/ohasd.bin "reboot"
Sep 24 16:05:19 mhddb-nb-2p.philadelphia.pa.bo.comcast.net root: exec /u01/app/grid/perl/bin/perl -I/u01/app/grid/perl/lib /u01/app/grid/bin/crswrap
Johnston, Nathaniel [10:40 AM]:
Sep 24 16:05:36 mhddb-nb-2p.philadelphia.pa.bo.comcast.net mDNSResponder (Engineering Build) (Nov 2 2009 05:02:07) [5272]: starting
Sep 24 16:05:37 mhddb-nb-2p.philadelphia.pa.bo.comcast.net mDNSResponder: Oracle mDNSResponder starting
======================================
WORKAROUND
======================================
| 11gR2 CRS doesn't startup after node reboot [ID 1050164.1] | |||||
| Modified 31-JAN-2010 Type PROBLEM Status PUBLISHED | |||||
In this Document
Symptoms
Changes
Cause
Solution
Applies to:
Oracle Server - Enterprise Edition - Version: 11.2.0.1.0 to 11.2.0.1.0 - Release: 11.2 to 11.2Generic Linux
Symptoms
- Installation of the 11gR2 Grid Infrastructure on a Linux cluster completed successfully
- OCR & Voting files located in ASM diskgroup
- using ASMLIB driver
- ASM disks are located on multipath devices (/dev/mapper/)
- following a node reboot CRS does not startup
- CSS daemon log shows the following message:
2010-01-13 09:04:15.075: [ CSSD][1150449984]clssnmvDDiscThread: using discovery string for initial discovery
2010-01-13 09:04:15.075: [ SKGFD][1150449984]Discovery with str::
2010-01-13 09:04:15.075: [ SKGFD][1150449984]UFS discovery with ::
2010-01-13 09:04:15.075: [ SKGFD][1150449984]OSS discovery with ::
2010-01-13 09:04:15.076: [ SKGFD][1150449984]Discovery with asmlib :ASM:/opt/oracle/extapi/64/asm/orcl/1/libasm.so: str ::
2010-01-13 09:04:15.076: [ SKGFD][1150449984]Fetching asmlib disk :ORCL:DATA1:
2010-01-13 09:04:15.076: [ SKGFD][1150449984]Fetching asmlib disk :ORCL:DATA2:
2010-01-13 09:04:15.076: [ SKGFD][1150449984]Fetching asmlib disk :ORCL:DATA3:
2010-01-13 09:04:15.076: [ SKGFD][1150449984]Fetching asmlib disk :ORCL:DATA4:
2010-01-13 09:04:15.077: [ SKGFD][1150449984]ERROR: -15(asmlib ASM:/opt/oracle/extapi/64/asm/orcl/1/libasm.so op asm_open error Operation not permitted)
2010-01-13 09:04:15.077: [ SKGFD][1150449984]ERROR: -15(asmlib ASM:/opt/oracle/extapi/64/asm/orcl/1/libasm.so op asm_open error Operation not permitted)
2010-01-13 09:04:15.077: [ SKGFD][1150449984]ERROR: -15(asmlib ASM:/opt/oracle/extapi/64/asm/orcl/1/libasm.so op asm_open error Operation not permitted)
2010-01-13 09:04:15.077: [ SKGFD][1150449984]ERROR: -15(asmlib ASM:/opt/oracle/extapi/64/asm/orcl/1/libasm.so op asm_open error Operation not permitted)
2010-01-13 09:04:15.077: [ CSSD][1150449984]clssnmvDiskVerify: Successful discovery of 0 disks
2010-01-13 09:04:15.077: [ CSSD][1150449984]clssnmCompleteInitVFDiscovery: Completing initial voting file discovery
2010-01-13 09:04:15.077: [ CSSD][1150449984]clssnmvFindInitialConfigs: No voting files found
2010-01-13 09:04:15.077: [ CSSD][1150449984]###################################
2010-01-13 09:04:15.077: [ CSSD][1150449984]clssscExit: CSSD signal 11 in thread clssnmvDDiscThread
2010-01-13 09:04:15.077: [ CSSD][1150449984]###################################
2010-01-13 09:04:15.077: [ CSSD][1139960128]clssgmClientShutdown: total iocapables 0
2010-01-13 09:04:15.077: [ CSSD][1139960128]clssgmClientShutdown: graceful shutdown completed.
2010-01-13 09:04:15.077: [ CSSD][1150449984] - running the cluster verification utility returns the following messages:
/cluvfy stage -post crsinst -n racnode1
Performing post-checks for cluster services setup
Checking node reachability...
Node reachability check passed from node "racnode1"
Checking user equivalence...
User equivalence check passed for user "grid"
Checking time zone consistency...
Time zone consistency check passed.
ERROR:
Cluster manager integrity check failed
PRVF-5434 : Cannot identify the current CRS software version
UDev attributes check for OCR locations started...
UDev attributes check passed for OCR locations
UDev attributes check for Voting Disk locations started...
ERROR:
PRVF-5197 : Failed to retrieve voting disk locations
UDev attributes check failed for Voting Disk locations
Default user file creation mask check passed
Checking cluster integrity...
Cluster integrity check failed This check did not run on the following node(s):
racnode1
Checking OCR integrity...
Checking the absence of a non-clustered configuration...
All nodes free of non-clustered, local-only configurations
ERROR:
PRVF-5300 : Failed to retrieve active version for CRS on this node
OCR integrity check failed
Checking CRS integrity...
ERROR:
PRVF-5300 : Failed to retrieve active version for CRS on this node
CRS integrity check failed
OCR detected on ASM. Running ACFS Integrity checks...
Starting check to see if ASM is running on all cluster nodes...
PRVF-5137 : Failure while checking ASM status on node "racnode1"
Starting Disk Groups check to see if at least one Disk Group configured...
PRVF-5112 : An Exception occurred while checking for Disk Groups
PRVF-5114 : Disk Group check failed. No Disk Groups configured
Task ACFS Integrity check failed
Checking Oracle Cluster Voting Disk configuration...
ERROR:
PRVF-5434 : Cannot identify the current CRS software version
PRVF-5431 : Oracle Cluster Voting Disk configuration check failed
User "grid" is not part of "root" group. Check passed
Post-check for cluster services setup was unsuccessful on all the nodes.
Changes
Node was rebooted after install.Cause
The CSS daemon crashes because it cannot locate any Voting files in any of the discovered ASM disks, which is indicated by the following message in the CSS daemon log (/log//cssd/ocssd.log):
2010-01-13 09:04:15.077: [ CSSD][1150449984]clssnmvFindInitialConfigs: No voting files foundThis error is preceded by the following ASMLIB error:
2010-01-13 09:04:15.077: [ SKGFD][1150449984]ERROR: -15(asmlib ASM:/opt/oracle/extapi/64/asm/orcl/1/libasm.so op asm_open error Operation not permitted)Solution
1. either edit the file /etc/sysconfig/oracleasm-_dev_oracleasm and change the lines:ORACLEASM_SCANORDER=""
ORACLEASM_SCANEXCLUDE=""ORACLEASM_SCANORDER="dm"
ORACLEASM_SCANEXCLUDE="sd"/usr/sbin/oracleasm configure -i -e -u user -g group -o "dm" -x "sd"2. stop & restart ASMLIB as user root using:
/usr/sbin/oracleasm exit
/usr/sbin/oracleasm init3. restart CRS or reboot node
The above steps need to be executed on all nodes
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