RAC Cheat Sheet

RAC Cheat Sheet:

Acronyms
GCS	Global Cache Services	in memory database containing current locks and awaiting locks, also known as PCM
GES	Global Enqueue Services	coordinates the requests of all global enqueues uses the GCS, also known as non-PCM
GRD	Global Resource Directory	all resources available to the cluster (formed and managed by GCS and GES), see GRDfor more details
GRM	Global Resource Manager	helps to coordinate and communicate the locks requests between Oracle processes
GSD	Global Services Daemon	runs on each node with one GSD process per node. The GSD coordinates with the cluster manager to receive requests from clients such as the DBCA, EM, and the SRVCTL utility to execute administrative job tasks such as instance startup or shutdown. The GSD is not an Oracle instance background process and is therefore not started with the Oracle instance
PCM (IDLM)	Parallel Cache Management	formly know as (integrated) Distributed Lock Manager, its another name for GCS
Resource	n/a	it is a identifiable entity it basically has a name or a reference, it can be a area in memory, a disk file or an abstract entity
Resource (Global)	n/a	a resource that can be accessed by all the nodes within the cluster examples would be the following Data Buffer Cache Block Transaction Enqueue Database Data Structures
LVB	Lock Value Block	contains a small amount of data regarding the lock
TRFC	Traffic Controller	controls the DLM traffic between instances (messaging tickets)

Files and Directories

Files and Directories
$ORA_CRS_HOME/cdata/<cluster_name>	OCR backups (default location)
$ORA_HOME/log/<hostname>/client/ocrconfig_<pid>.log	OCR command log file
$ORA_CRS_HOME/crs/log	contains trace files for the CRS resources
$ORA_CRS_HOME/crs/init	contains trace files for the CRS daemon during startup, a good place to start
$ORA_CRS_HOME/css/log	contains cluster reconfigurations, missed check-ins, connects and disconnects from the client CSS listener. Look here to obtain when reboots occur
$ORA_CRS_HOME/css/init	contains core dumps from the cluster synchronization service daemon (OCSd)
$ORA_CRS_HOME/evm/log	logfiles for the event volume manager and eventlogger daemon
$ORA_CRS_HOME/evm/init	pid and lock files for EVM
$ORA_CRS_HOME/srvm/log	logfiles for Oracle Cluster Registry (OCR)
$ORA_CRS_HOME/log	log fles for Oracle clusterware which contains diagnostic messages at the Oracle cluster level

Useful Views/Tables

GCS and Cache Fusion Diagnostics
v$cache	contains information about every cached block in the buffer cache
v$cache_transfer	contains information from the block headers in SGA that have been pinged at least once
v$instance_cache_transfer	contains information about the transfer of cache blocks through the interconnect
v$cr_block_server	contains statistics about CR block transfer across the instances
v$current_block_server	contains statistics about current block transfer across the instances
v$gc_element	contains one-to-one information for each global cache resource used by the buffer cache
GES diagnostics
v$lock	contains information about locks held within a database and outstanding requests for locks and latches
v$ges_blocking_enqueue	contains information about locks that are being blocked or blocking others and locks that are known to the lock manager
v$enqueue_statistics	contains details about enqueue statistics in the instance
v$resource_limits	display enqueue statistics
v$locked_object	contains information about DML locks acquired by different transactions in databases with their mode held
v$ges_statistics	contains miscellaneous statistics for GES
v$ges_enqueue	contains information about all locks known to the lock manager
v$ges_convert_local	contains information about all local GES operations
v$ges_convert_remote	contains information about all remote GES operations
v$ges_resource	contains information about all resources known to the lock manager
v$ges_misc	contains information about messaging traffic information
v$ges_traffic_controller	contains information about the message ticket usage
Dynamic Resource Remastering
v$hvmaster_info	contains information about current and previous master instances of GES resources in relation to hash value ID of resource
v$gcshvmaster_info	the same as above but globally
v$gcspfmaster_info	conatins information about current and previous masters about GCS resources belonging to files mapped to a particular master, including the number of times the resource has remastered
Cluster Interconnect
v$cluster_interconnects	contains information about interconnects that are being used for cluster communication
v$configured_interconnects	same as above but also contains interconnects that AC is aware off that are not being used
Miscellanous
v$service	services running on an instance
x$kjmsdp	display LMS daemon statistics
x$kjmddp	display LMD daemon statistics

Useful Parameters

Parameters
cluster_interconnects	specify a specific IP address to use for the inetrconnect
_gcs_fast_config	enables fast reconfiguration for gcs locks (true|false)
_lm_master_weight	controls which instance will hold or (re)master more resources than others
_gcs_resources	controls the number of resources an instance will master at a time
_lm_tickets	controls the number of message tickets
_lm_ticket_active_sendback	controls the number of message tickets (aggressive messaging)
_db_block_max_cr_dba	limits the number of CR copies per DBA on the buffer cache (see grd)
_fairness_threshold	used when too many CR requested arrive for a particular buffer and the block becomes disowned (see grd)
_gc_affinity_time	specifies interval minutes for reamstering
_gc_affinity_limit	defines the number of times a instance access the resource before remastering
_gc_affinity_minimum	defines the minimum number of times a instance access the resource before remastering
_lm_file_affinity	disables dynamic remastering for the objects belonging to those files
_lm_dynamic_remastering	enable or disable remastering
_gc_defer_time	define the time by which an instance deferred downgrading a lock (see Cache Fusion)
_lgwr_async_broadcast	change the SCN boardcast method (see troubleshooting)

Processes

Oracle RAC Daemons and Processes
OPROCd	Process Monitor	provides basic cluster integrity services
EVMd	Event Management	spawns a child process event logger and generates callouts
OCSSd	Cluster Synchronization Services	basic node membership, group services, basic locking
CRSd	Cluster Ready Services	resource monitoring, failover and node recovery
LMSn	Lock Manager Server process - GCS	this is the cache fusion part, it handles the consistent copies of blocks that are tranferred between instances. It receives requests from LMD to perform lock requests. I rools back any uncommitted transactions. There can be upto ten LMS processes running and can be started dynamically if demand requires it. they manage lock manager service requests for GCS resources and send them to a service queue to be handled by the LMSn process. It also handles global deadlock detection and monitors for lock conversion timeouts.
LMON	Lock Monitor Process - GES	this process manages the GES, it maintains consistency of GCS memory in case of process death. It is also responsible for cluster reconfiguration and locks reconfiguration (node joining or leaving), it checks for instance deaths and listens for local messaging. A detailed log file is created that tracks any reconfigurations that have happened.
LMD	Lock Manager Daemon - GES	this manages the enqueue manager service requests for the GCS. It also handles deadlock detention and remote resource requests from other instances.
LCK0	Lock Process - GES	manages instance resource requests and cross-instance call operations for shared resources. It builds a list of invalid lock elements and validates lock elements during recovery.
DIAG	Diagnostic Daemon	This is a lightweight process, it uses the DIAG framework to monitor the healt of the cluster. It captures information for later diagnosis in the event of failures. It will perform any neccessary recovery if an operational hang is detected.

General Administration

Managing the Cluster
starting	/etc/init.d/init.crs start crsctl start crs
stopping	/etc/init.d/init.crs stop crsctl stop crs
enable/disable at boot time	/etc/init.d/init.crs enable /etc/init.d/init.crs disable crsctl enable crs crsctl disable crs
Managing the database configuration with SRVCTL
start all instances	srvctl start database -d <database> -o <option> Note: starts listeners if not already running, you can use the -o option to specify startup/shutdown options force open mount nomount
stop all instances	srvctl stop database -d <database> -o <option> Note: the listeners are not stopped, you can use the -o option to specify startup/shutdown options immediate abort normal transactional
start/stop particular instance	srvctl [start|stop] database -d <database> -i <instance>,<instance>
display the registered databases	srvctl config database
status	srvctl status database -d <database> srvctl status instance -d <database> -i <instance>,<instance> srvctl status service -d <database> srvctl status nodeapps -n <node> srvctl status asm -n <node>
stopping/starting	srvctl stop database -d <database> srvctl stop instance -d <database> -i <instance>,<instance> srvctl stop service -d <database> -s <service>,<service> -i <instance>,<instance> srvctl stop nodeapps -n <node> srvctl stop asm -n <node> srvctl start database -d <database> srvctl start instance -d <database> -i <instance>,<instance> srvctl start service -d <database> -s <service>,<service> -i <instance>,<instance> srvctl start nodeapps -n <node> srvctl start asm -n <node>
adding/removing	srvctl add database -d <database> -o <oracle_home> srvctl add instance -d <database> -i <instance> -n <node> srvctl add service -d <database> -s <service> -r <preferred_list> srvctl add nodeapps -n <node> -o <oracle_home> -A <name|ip>/network srvctl add asm -n <node> -i <asm_instance> -o <oracle_home> srvctl remove database -d <database> -o <oracle_home> srvctl remove instance -d <database> -i <instance> -n <node> srvctl remove service -d <database> -s <service> -r <preferred_list> srvctl remove nodeapps -n <node> -o <oracle_home> -A <name|ip>/network srvctl asm remove -n <node>
OCR utilities
log file	$ORA_HOME/log/<hostname>/client/ocrconfig_<pid>.log
checking	ocrcheck Note: will return the OCR version, total space allocated, space used, free space, location of each device and the result of the integrity check
dump contents	ocrdump -backupfile <file> Note: by default it dumps the contents into a file named OCRDUMP in the current directory
export/import	ocrconfig -export <file> ocrconfig -restore <file>
backup/restore	# show backups ocrconfig -showbackup # to change the location of the backup, you can even specify a ASM disk ocrconfig -backuploc <path|+asm> # perform a backup, will use the location specified by the -backuploc location ocrconfig -manualbackup # perform a restore ocrconfig -restore <file> # delete a backup orcconfig -delete <file> Note: there are many more option so see the ocrconfig man page
add/remove/replace	## add/relocate the ocrmirror file to the specified location ocrconfig -replace ocrmirror '/ocfs2/ocr2.dbf' ## relocate an existing OCR file ocrconfig -replace ocr '/ocfs1/ocr_new.dbf' ## remove the OCR or OCRMirror file ocrconfig -replace ocr ocrconfig -replace ocrmirror

CRS Administration

CRS Administration
starting	## Starting CRS using Oracle 10g R1 not possible ## Starting CRS using Oracle 10g R2 $ORA_CRS_HOME/bin/crsctl start crs
stopping	## Stopping CRS using Oracle 10g R1 srvctl stop database -d <database> srvctl stop asm -n <node> srvctl stop nodeapps -n <node> /etc/init.d/init.crs stop ## Stopping CRS using Oracle 10g R2 $ORA_CRS_HOME/bin/crsctl stop crs
disabling/enabling	## use to stop CRS restarting after a reboot ## Oracle 10g R1 /etc/init.d/init.crs [disable|enable] ## Oracle 10g R2 $ORA_CRS_HOME/bin/crsctl [disable|enable] crs
checking	$ORA_CRS_HOME/bin/crsctl check crs $ORA_CRS_HOME/bin/crsctl check evmd $ORA_CRS_HOME/bin/crsctl check cssd $ORA_CRS_HOME/bin/crsctl check crsd $ORA_CRS_HOME/bin/crsctl check install -wait 600
Resource Applications (CRS Utilities)
status	$ORA_CRS_HOME/bin/crs_stat
create profile	$ORA_CRS_HOME/bin/crs_profile
register/unregister application	$ORA_CRS_HOME/bin/crs_register $ORA_CRS_HOME/bin/crs_unregister
Start/Stop an application	$ORA_CRS_HOME/bin/crs_start $ORA_CRS_HOME/bin/crs_stop
Resource permissions	$ORA_CRS_HOME/bin/crs_getparam $ORA_CRS_HOME/bin/crs_setparam
Relocate a resource	$ORA_CRS_HOME/bin/crs_relocate
Nodes
member number/name	olsnodes -n
local node name	olsnodes -l
activates logging	olsnodes -g
Oracle Interfaces
display	oifcfg getif
delete	oicfg delig -global
set	oicfg setif -global <interface name>/<subnet>:public oicfg setif -global <interface name>/<subnet>:cluster_interconnect
Global Services Daemon Control
starting	gsdctl start
stopping	gsdctl stop
status	gsdctl status
Cluster Configuration (clscfg is used during installation)
create a new configuration	clscfg -install
upgrade or downgrade and existing configuration	clscfg -upgrade clscfg -downgrade
add or delete a node from the configuration	clscfg -add clscfg -delete
create a special single-node configuration for ASM	clscfg -local
brief listing of terminology used in the other nodes	clscfg -concepts
used for tracing	clscfg -trace
help	clscfg -h
Cluster Name Check
print cluster name	cemulto -n Note: in Oracle 9i the ulity was called "cemutls"
print the clusterware version	cemulto -w Note: in Oracle 9i the ulity was called "cemutls"
Node Scripts
Add Node	addnode.sh Note: see adding and deleting nodes
Delete Node	deletenode.sh Note: see adding and deleting nodes
Enqueues
displaying statistics	SQL> column current_utilization heading current SQL> column max_utilization heading max_usage SQL> column initial_allocation heading initial SQL> column resource_limit format a23; SQL> select * from v$resource_limit;
Messaging (tickets)
ticket usage	select local_nid local, remote_nid remote, tckt_avail avail, tckt_limit limit, snd_q_len send_queue, tckt_wait waiting from v$ges_traffic_controller;
dump ticket information	SQL> oradebug setmypid SQL> oradebug unlimit SQL> oradebug lkdebug -t
Lighwork Rule and Fairness Threshold
downconvert	select cr_requests, light_works, data_requests, fairness_down_converts from v$cr_block_server; Note: lower the _fairness_threshold if the ratio goes above 40%, set to 0 if the instance is a query only instance.
Remastering
force dynamic remastering (DRM)	## Obtain the OBJECT_ID form the below table SQL> select * from v$gcspfmaster_info; ## Determine who masters it SQL> oradebug setmypid SQL> oradebug lkdebug -a <OBJECT_ID> ## Now remaster the resource SQL> oradebug setmypid SQL> oradebug lkdebug -m pkey <OBJECT_ID>
GRD, SRVCTL, GSD and SRVCONFIG Tracing
Enable tracing	$ export SRVM_TRACE=true
Disable tracing	$ export SRVM_TRACE=""

Voting Disk

adding	crsctl add css votedisk <file>
deleting	crsctl delete css votedisk <file>
querying	crsctl query css votedisk