Can try flushing the cache:
alter system flush buffer_cache;
Showing posts with label RAC. Show all posts
Showing posts with label RAC. Show all posts
Monday, December 5, 2016
Monday, September 28, 2015
Session hang because 'gc cr request' and 'cr request retry'
In 11g Rac, during datapump import, session hangs at step of importing indexes or constraints.
If you check v$session_wait for the sid, you may notice 'gc cr request' and 'cr request retry':
Mostly it's caused by Redo log IO performance or the interconnect performance.
You can try:
1) Improve the interconnect performance.
2) Improve the Redo log I/o performance.
3) Set undersore parameter "_cr_server_log_flush" =false.
If you check v$session_wait for the sid, you may notice 'gc cr request' and 'cr request retry':
SQL> select event from
v$session_wait where sid=405;
EVENT
----------------------------------------------------------------
gc cr request
SQL> select event from
v$session_wait where sid=405;
EVENT
----------------------------------------------------------------
cr request retry
Mostly it's caused by Redo log IO performance or the interconnect performance.
You can try:
1) Improve the interconnect performance.
2) Improve the Redo log I/o performance.
3) Set undersore parameter "_cr_server_log_flush" =false.
Wednesday, July 4, 2012
11gR2 Rac install on Centos 6.2 without Oracle ASMLib
Oracle ASMlib is available for linux prior to OL6 or RedHat 6. However, starting from 6, you can only use asmlib for UEK kernel.
On Linux, the built in udev is definitely a better solution to handle persistent device naming and permissions.
Without ASMLib, you don't need to worry about the raw disks everytime when there's a kernel update.
Tuesday, June 19, 2012
What are cvutrace.log.* files
I was looking to clear some space recently and ran across a 21G directory (<grid_infrastructure_home>/cv/log). Inside there were a lot of files like “cvutrace.log.0_20100720015347″. These files are log files related to a RAC installation. They can safely be deleted.
To stop the files from being generated is add the following at the top of the cluvfy script in the <grid_infrastructure_home>/bin directory.
Windows:
set SRVM_TRACE=false
AIX:
export SRVM_TRACE=false
I was looking to clear some space recently and ran across a 21G directory (<grid_infrastructure_home>/cv/log). Inside there were a lot of files like “cvutrace.log.0_20100720015347″. These files are log files related to a RAC installation. They can safely be deleted.
To stop the files from being generated is add the following at the top of the cluvfy script in the <grid_infrastructure_home>/bin directory.
Windows:
set SRVM_TRACE=false
AIX:
export SRVM_TRACE=false
Friday, April 27, 2012
oradebug
In Oracle database version 9i there is no way to determine the IP address through a database view. The only way to determine this IP address is with the oradebug command (Please keep in mind oradebug is not a supported product from Oracle, so if there are problems/crashes you are on your own). The oradebug ipc command creates a trace file. The example shows the process:
SQL> oradebug setmypid
SQL> oradebug ipc
SQL> oradebug tracefile_name
The last command will show the name of the created trace file. The next step is opening the trace file and looking for the string SKGXPCTX. The following is a typical example.
SKGXPCTX: 0xcd1e730 ctx
admno 0x7a0be402 admport:
SSKGXPT 0xcd1e884 flags SSKGXPT_READPENDING info for network 0
socket no 8 IP 140.87.79.67 UDP 9152
sflags SSKGXPT_WRITESSKGXPT_UP
info for network 1
The cluster interconnect IP address is shown in bold. In the example above
it is 140.87.79.67.
In Oracle database version 9i there is no way to determine the IP address through a database view. The only way to determine this IP address is with the oradebug command (Please keep in mind oradebug is not a supported product from Oracle, so if there are problems/crashes you are on your own). The oradebug ipc command creates a trace file. The example shows the process:
SQL> oradebug setmypid
SQL> oradebug ipc
SQL> oradebug tracefile_name
The last command will show the name of the created trace file. The next step is opening the trace file and looking for the string SKGXPCTX. The following is a typical example.
SKGXPCTX: 0xcd1e730 ctx
admno 0x7a0be402 admport:
SSKGXPT 0xcd1e884 flags SSKGXPT_READPENDING info for network 0
socket no 8 IP 140.87.79.67 UDP 9152
sflags SSKGXPT_WRITESSKGXPT_UP
info for network 1
The cluster interconnect IP address is shown in bold. In the example above
it is 140.87.79.67.
Modify the attribute AUTO_START to “always”
With Oracle 11.2 database auto start
policy in the clusterware is restore, which means that clusterware will
remember the last state of the database. If the database was stopped
normally then on the next restart of clusterware it won’t be started. Otherwise
if the server crashes or by some reason the OS is rebooted then clusterware
will start the database because last state was ONLINE (running).
Monday, April 16, 2012
Resize Redo log for RAC
In RAC, you have seperate log groups for each instance (called threads). You can see which group belongs to which thread by querying v$log. When you add new loggroups, you specify which thread it should belong to. The syntax is
ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 5 ('firstlocation','secondlocation') SIZE 1280M;
In RAC, you have seperate log groups for each instance (called threads). You can see which group belongs to which thread by querying v$log. When you add new loggroups, you specify which thread it should belong to. The syntax is
ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 5 ('firstlocation','secondlocation') SIZE 1280M;
Enable/Disable Archive logs in a RAC environment
on node 1:
set oracle_sid=racdb1
-------------Noarchivelog
sqlplus / as sysdba
alter system set cluster_database=false scope=spfile sid='racdb2';
quit
on node 1:
set oracle_sid=racdb1
-------------Noarchivelog
sqlplus / as sysdba
alter system set cluster_database=false scope=spfile sid='racdb2';
quit
Friday, March 9, 2012
Oracle 11gR2 RAC on Windows 2008 using VMWARE
Oracle 11gR2 RAC on Windows 2008 R2 using VMWARE
Network Configuration
Name the network connection as “public” and “private”
Amend the C:\windows\system32\drivers\etc\hosts file to contain the following information.
127.0.0.1 localhost.localdomain localhost
# Public
192.168.96.3 rac1.localdomain rac1
192.168.96.4 rac2.localdomain rac2
#Private
192.168.40.2 rac1-priv.localdomain rac1-priv
192.168.40.3 rac2-priv.localdomain rac2-priv
#Virtual
192.168.96.111 rac1-vip.localdomain rac1-vip
192.168.96.112 rac2-vip.localdomain rac2-vip
# SCAN
192.168.96.201 rac-scan.localdomain rac-scan
Addition changes:First, ensure the public interface is first in the bind order:
Network Configuration
Name the network connection as “public” and “private”
Amend the C:\windows\system32\drivers\etc\hosts file to contain the following information.
127.0.0.1 localhost.localdomain localhost
# Public
192.168.96.3 rac1.localdomain rac1
192.168.96.4 rac2.localdomain rac2
#Private
192.168.40.2 rac1-priv.localdomain rac1-priv
192.168.40.3 rac2-priv.localdomain rac2-priv
#Virtual
192.168.96.111 rac1-vip.localdomain rac1-vip
192.168.96.112 rac2-vip.localdomain rac2-vip
# SCAN
192.168.96.201 rac-scan.localdomain rac-scan
Addition changes:First, ensure the public interface is first in the bind order:
How to find Cluster name on RAC instance
Soemtimes you need to check your cluster name on your RAC instance. Here is the steps:
Adding and removing disks in ASM
Adding and removing disks in ASM
A first for me. I had seen asm in the past but never had hands on experience with it. A client needed some disks moved from 1 diskgroup to the other and so started my journey into ASM. :)
A first for me. I had seen asm in the past but never had hands on experience with it. A client needed some disks moved from 1 diskgroup to the other and so started my journey into ASM. :)
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