maximizing oracle real application clusters 11g sharing the load with services
TRANSCRIPT
© 2008 Hewlett-Packard Development Company, L.P.The information contained herein is subject to change without notice.
James Harding - Database Manager Sabre
Sherri Trojan - Database Architect HP
October 2, 2009
Maximizing Oracle Real Application Clusters 11g: Sharing the Load with Services
Today
GoldenGate Data Pump Servers
Logical standby DB
Oracle Master DB Oracle
Re-Do Logs
Content Application Servers - CRUD Activity GenGen
GoldenGate Extractor/Replicator
Gen Gen
160 MySQL Database Servers
Oracle Database Servers (3-SCC, 3-CDC)
Gen Gen
AVS DSS
GenGen
Gen
Hist
AVS DSS
GenGen
Gen
Hist
1
23
4
5
6
GG Local Trails
Extract Trail Split
GG Remote Trails
Tomorrow
GoldenGate Data Pump Servers
Logical standby DB
Oracle Master DB Oracle
Re-Do Logs
Content Application Servers - CRUD Activity
GoldenGate Extractor/Replicator
8 Oracle 2 Node RAC Database Clusters - Blades
Oracle Database Servers (3-SCC, 3-CDC)
1
23
4
5
GG Local Trails
Extract Trail Split
GG Remote Trails
Objective• Improve:
−Capacity & Scalability
−Operation Support
−Performance Monitoring & Performance Management Features
• Phase 1:−Connection Load Balance
−Home grown connection pooling
−Clients notify us that there is a problem.
• Phase 2:−Runtime Load Balance
−Oracle connection pooling
−We notify the client that there is a problem.
Any sufficiently advanced technology is indistinguishable from magic. Arthur C. Clark
APP1 APP1APP2 APP2 APP3
RAC Service Station
APP1 APP1
Load balance to server with least load
Performance
Trace
AWR
Failover
Load balance
Monitor
Event
Services
provide
for:
Sharing the Load with Services4 Main Options:
•Client side connection load balancing
•Server side connection load balancing
•Server side connection load balancing with Load Balancing advisor
•Runtime Load balancing with Load balancing advisor
Client side connection load balancing
Load Balance On Connection
Client Side - TNSNAMESCLIENT1 = (DESCRIPTION = (LOAD_BALANCE = ON) # ON=Random Connections OFF=Sequential connections (FAILOVER = ON) # Activates failover when TCP timeout is reached (ADDRESS = (PROTOCOL = TCP)(HOST = raclinux1-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = raclinux2-vip)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = racdb) ) )
Random connections one listener is not overwhelmed
Server side connection load balancing
Balances incoming connections across all of the instances that provide the requested database service.
Load Balancing Advisor – Uses current service levels
Connection Load Balancing• Short - Use Load Balancing Advisory, when Load Balancing
Advisory is enabled with Service Goals.• Long - Balances the number of connections per instance
using session count per service.
Service Goals• None• Service Time - Best response time – elapsed time
per call metric. Example: Internet shopping
• Throughput - Better throughput – rate that work is completed
per second metric. Example: Batch
On Connection – Server Side
Load Balancing Advisor : ON or OFF
•Add a service: srvctl add service -d RACDB1 -s SERV1 -r LINUX1 -a LINUX2 -P basic
-r = Preferred list -a = available list (failover)
•Start service: srvctl start service -d RACDB1 -s SERV1
•List services in OCR: srvctl config service -d RACDB1 -a
•Create TNS Entry
•Use DBMS_SERVICE.MODIFY_SERVICE to set goals and failover
•Verify service in listener: lsnrctl status
•List services in listener: lsnrctl services
Adding a service
Can be done with DBCA, OEM, SRVCTL
From sqlplus, modify service for goals:
BEGIN
DBMS_SERVICE.MODIFY_SERVICE(
service_name => 'racload'
,failover_method => DBMS_SERVICE.FAILOVER_METHOD_BASIC
,failover_type => DBMS_SERVICE.FAILOVER_TYPE_SESSION,
,failover_retries => 10,
,failover_delay => 1,
,goal => DBMS_SERVICE.GOAL_SERVICE_TIME
,clb_goal => DBMS_SERVICE.CLB_GOAL_SHORT );
END;
/
Service with Load Balance Advisor
PMON process communicates with other listeners
•PMON process registers database with database’s local listener•Cross-registers database with listeners on all other nodes in the cluster •PMON by default checks CPU every 3 seconds•PMON updates the listener with statistics. By default, PMON updates TNSLSNR every 10 minutes.•Listener routes incoming connections to the least loaded instance.
Server Side Load Balancing
PMON
Listener ListenerListener
TNSNAMES entry
LISTENERS_RACDB = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = rac3-vip)(PORT = 1521))
How does PMON which listeners to register with?
Server Side Load Balancing
PMON
Listener ListenerListener
init.ora: REMOTE_LISTENERS=LISTENERS_RACDB
MMNL sys.sys$Service_metrics_tab
PMONMMON
AQ
Listener Listener ListenerFan Event
ONS$CRS_HOME/opmn/conf/
ons.config
MMNL - Memory Monitor LightMMON - Manageability MonitorONS - Oracle Notification Service
Updated every 30sHas FAN events
Load Balancing Advisor processes
Fast connection failover
racgimon
Updated every few seconds - 10 minutes
OCI.NET
Java JDBC
2009-03-02 11:54:47.373624 : nsglb:instance:RACNY11 new lbscore:3002009-03-02 11:54:48.422227 : nsglb:instance:RACNY21 new lbscore:1002009-03-02 11:54:49.477567 : nsglb:instance:RACNY21 new lbscore:2002009-03-02 11:54:50.536465 : nsglb:instance:RACNY21 new lbscore:3002009-03-02 11:54:51.589902 : nsglb:instance:RACNY21 new lbscore:4002009-03-02 11:54:52.642743 : nsglb:instance:RACNY11 new lbscore:4002009-03-02 11:54:53.703777 : nsglb:instance:RACNY21 new lbscore:500
• Oracle 10.2 and higher: Listener uses a local value "lbscore“• Lbscore : two dynamic values "goodness" and "delta" • Continuously updated by PMON. • PMON contacts the listener and provides starting values for goodness and delta...
Listener lbscore = Goodness from PMON Listener Delta = Delta from PMON
• To account for changes in load between PMON updates the listener will increment the lbscore after each new incoming connection...
Listener lbscore = Listener lbscore(previous) + Listener Delta
LBSCORE – Surge Protection
•PMON updates the listener with instance load and dispatcher information•PMON SERVICE_UPDATE’s vary according to the workload of the instance•The maximum interval between these service updates is 10 minutes.
Update listener information
05-MAR-2009 13:31:15 * service_update * RACNY11 * 005-MAR-2009 13:31:16 * service_update * RACTX22 * 005-MAR-2009 13:31:19 * service_update * RACTX21 * 005-MAR-2009 13:31:31 * service_update * RACTX22 * 005-MAR-2009 13:31:52 * service_update * RACNY12 * 0
Setting a Listener Trace:’ lsnrctl set trc_level 16’ produces a trace log that shows the Load Balance Advisory
updates2009-03-05 16:24:17.185722 : nsglgrDoRegister:inst loads: ld1:102 mld1:81920 ld2:17
mld2:60002009-03-05 16:24:17.185746 : nsglgrDoRegister:service:RACNY_STAGING what:4 value:12009-03-05 16:24:17.185763 : nsglgrDoRegister:service:RACNY_STAGING what:2 value:02009-03-05 16:24:17.185799 : nsglgrDoRegister:service:RACNY_RTG what:4 value:1002009-03-05 16:24:17.185817 : nsglgrDoRegister:service:RACNY_RTG what:2 value:1002009-03-05 16:24:17.186112 : nsglgrDoRegister:service:RACNY1 what:4 value:12009-03-05 16:24:17.186129 : nsglgrDoRegister:service:RACNY1 what:2 value:22009-03-05 16:24:17.186157 : nsglgrDoRegister:exit2009-03-05 16:24:17.186193 : nsdo:entry
What:4 = Delta What: 2 = Goodnessld1 = node load - load average ld2 = instance load - number user
sessionsmld1 = max load data/ max cpu
capacity mld2 = max load data/sessions init.ora
Check Listener log. When busy, it updated every few seconds
Load Balance – Multi Cluster
ractx
racpl racok
rachp
sqlplus name/pass@racload
GOODNESS: 15
GOODNESS: 100
GOODNESS: 15
GOODNESS: 20
racny
Load Balancing
Server side Load Balancing across clusters
ractx
racpl racok
rachp
sqlplus name/pass@racload
GOODNESS: 15
GOODNESS: 100
GOODNESS: 15
GOODNESS: 20
racny
GOODNESS 1
Load Balancing
Server side Load Balancing across clusters
Goodness: ranking for the quality of service that the service is experiencing at an instance level, including whether access has been restricted from an instance. Lower number is better
LISTENERS_RACDBALL = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = ractx1-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = ractx2-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = racpl1-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = racpl2-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = racok1-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = racok2-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = rachp1-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = rachp2-vip)(PORT = 1521)) )
'ALTER SYSTEM SET REMOTE_LISTENER = LISTENERS_RACDBALL SID='*' SCOPE=BOTH;'
TNS Entry
SPFILE Create RAC service (from unix srvctl command) srvctl config service -d ractx -a srvctl add service -d ractx -s racload -r ractx1, ractx2 -P basic srvctl start service -d ractx -s racload srvctl config service -d ractx -a
From sqlplus, modify service for goals:BEGINDBMS_SERVICE.MODIFY_SERVICE( service_name => 'racload' ,failover_method => DBMS_SERVICE.FAILOVER_METHOD_BASIC ,failover_type => DBMS_SERVICE.FAILOVER_TYPE_SESSION, ,failover_retries => 10, ,failover_delay => 1, ,goal => DBMS_SERVICE.GOAL_SERVICE_TIME ,clb_goal => DBMS_SERVICE.CLB_GOAL_SHORT );END;/
ractx racpl racok rachp
sqlplus name/pass@racload
GOODNESS: 1 GOODNESS: 100GOODNESS: 1GOODNESS: 10
Verify service in listener: lsnrctl statusList services in listener: lsnrctl
services
Server side Load Balancing across clusters
Bringing a multi-cluster online• Duplicate rac database• Start replication• Add services with goals • Add entry to tnsnames remote_listener entry:• Alter system set remote_listener='LISTENERS_RACDB1';• $ lsnctl status
should show all 4 instances for each oracle service
Service "RACDB_MYAPP" has 4 instance(s). Instance "RACDB11", status READY, has 16 handler(s) for this service... Instance "RACDB12", status READY, has 16 handler(s) for this service... Instance "RACDB21", status READY, has 17 handler(s) for this service... Instance "RACDB22", status READY, has 16 handler(s) for this service...
• Client should set a TCP connect timeout. Syntax varies by client type
Example: SQLNET.OUTBOUND_CONNECT_TIMEOUT=4
Issue: Dispatcher blocked
•Listener log: TNS-12520 errors
•lsnrctl services:Service "RACDB_AS" has 2 instance(s).Instance "RACDB1", status READY, has 11 handler(s) for this
service...Handler(s):D009" established:15499 refused:0 current:972 max:972
state:blocked
•Sqlplus: select count(*) from v$circuit does not show many sessions
Dispatcher Blocked•Reason: Dispatcher defaults to public host. •Check in: ‘network' column of v$dispatcher •'lsnrctl services‘•It's also described in metalink note: 578524.1
Fix: alter system set dispatchers='(address=(protocol=tcp)(host=racdb-vip))
(dispatchers=10)’ (index=0) scope=both sid=‘RACDBxx'; Info:
A listener will hand off a connection to a dispatcher if it is local.
If it is remote, it will send the client a new host/port and the client
will reconnect to the dispatcher.
The fix was to modify the dispatcher with a host vip entry. This specifies
the endpoint listener.
Test Results
Load Balancing
HOST LOAD COUNT
RACNY
RACTX
racny1 0.269 156
racny2 0.729 92
ractx1 2.379 7
ractx2 0.419 119
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Average of goodness
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Swingbench with a slow ramp up of 250 sessions
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Average of load
time
Inst
racny11racny12ractx21tactx22
load
cpu goodness
Runtime Load Balancing
Allows Oracle Clients to provide intelligent allocations of connections based on the current service level provided by the database instances when applications request a connection to complete some work.
• OCI - Oracle Call Interface. Used in C and C++ as well as other languages that are built on top of OCI layer such as perl and PHP
• Thick JDBC - Build around OCI libraries to implement JCBC API standard for Java Language
• Thin JDBC - Native JDBC. Pure JAVA Implementation that does not need underlying OCI layer. Does not support TAF. Does support Fast Connection Failover.
• ODP.NET - Oracle Data Provider (ODP) for Microsoft’s .NET development platform. Based on OCI
Interface
•Oracle Notification Service (ONS) Communicates/interacts with components like the listener, application, etcserver-side ONS through ORA_CRS_HOME/opmn/conf/ons.config. Use racgons to add middle-tier node info to the OCRNo ONS daemon needed on the client when using Remote ONS SubscriptionOracle Clusterware and RAC utilize ONS to propagate FAN messages both within the RAC cluster, and to client or mid-tier machines
•FAN - Fast Application Notification quickly alert applications about configuration and workload service level changes
•FCF - Fast Connection Failover. (do not use TAF if using FCF)Supports both JDBC Thin and JDBC Oracle Call Interface (OCI) drivers.Requires ONSSubscribes to FAN events
Terms
To use FAN callouts: place an executable in the directory: CRS_home/racg/usrco on every node that runs CRS Example #! /bin/ksh FAN_LOGFILE= [your path name]/admin/log/`hostname`_uptime.log echo $* "reported="`date` >> $FAN_LOGFILE &
FAN events are published using ONS and Advanced Queuing. • The Connection Manager (CMAN) and Oracle Net Services Listeners are integrated with FAN events. • Listener and CMAN immediately de-register services provided by a failed instance
ONS is used to propagate FAN messages.
Verify ONS is running: srvctl status nodeapps -n {server} $CRS_HOME/bin/onsctl ping $CRS_HOME/bin/onsctl debug
Fast Application Notification
Runtime Load Balancing
• JAVA JDBC and JAVA thin − use ONS to subscribe to FAN events− Turning on Fast Connection Failover feature with JDBC includes Runtime Connection
Load Balancing
• OCI − Uses the System Alert Queue (aq) to subscribe to FAN events.− Runtime connection load balancing is enabled by default in a release 11.1 or higher
client talking to server of 10.2 or higher. − The application must have been linked with the threads library.− The OCI environment must be created in OCI_EVENTS and OCI_THREADED mode− DBMS_SERVICE.MODIFY_SERVICE(
service_name => 'MYSERVICE‘ ,aq_ha_notifications => true
,goal => DBMS_SERVICE.GOAL_SERVICE_TIME ,clb_goal => DBMS_SERVICE.CLB_GOAL_SHORT ); END; /
− To view: DBA_OUTSTANDING_ALERTS or DBA_ALERT_HISTORY.
Runtime Load balancing
• Balance connections across all of the Oracle RAC instances when a service starts; this is preferable to directing the sessions that are defined for the connection pool to the first Oracle RAC instance that supports the service
•Remove terminated connections immediately when a service is declared DOWN at an instance, and immediately when nodes are declared DOWN
•Report errors to clients immediately when Oracle detects the NOT RESTARTING state, instead of making the client wait while the service repeatedly attempts to restart
•Balance work requests at run time using load balancing advisory events
Transaction ApplicationFailover
Transaction Application Failover -
TNSNAMES Entry
STOCK = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = uspls330-vip)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = uspls331-vip)(PORT = 1521)) (LOAD_BALANCE = yes) (FAILOVER=on) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = stock) (FAILOVER_MODE = (TYPE = SELECT) (METHOD = BASIC) (RETRIES = 180) (DELAY = 5) ) ) )
Transaction Application Failover can also be associated with a service using the dbms_service package when using the BASIC method
session: Fails over the session; Does not attempt to recover selects.select: Allows users with open cursors to continue fetching on them after failure. Involves overhead on the client side in normal select operations.none: This is the default, in which no failover functionality is used.
METHOD: Specify how fast failover is to occur from the primary node to the backup node: basic: Establishes connections at failover time. This option requires almost no work on the backup database server until failover time. preconnect: Pre-establishes connections. This provides faster failover but requires that the backup instance be able to support all connections from every supported instance.
BEGINDBMS_SERVICE.MODIFY_SERVICE( service_name => ‘SERV1' ,goal => DBMS_SERVICE.GOAL_SERVICE_TIME ,clb_goal => DBMS_SERVICE.CLB_GOAL_SHORT ,failover_method => DBMS_SERVICE.FAILOVER_METHOD_BASIC ,failover_type => DBMS_SERVICE.FAILOVER_TYPE_SELECT ,failover_retries => 50 ,failover_delay => 5); END;
DBMS_SERVICE package
SQL>
What To Expect After TAF Failover
TYPE=SESSION• If any uncommitted transaction existed in the session ORA-25402: transaction must roll back
• If no active transactionSELECT statements will get ORA-25401: can not continue
fetchesEven though error may be returned, session will be connected
tosurviving instance and work may continue
TYPE=SELECTSimilar behavior to above, but SELECT statements will continue
fetches without interruption if no transaction in progress
Transaction Application Failover
Monitoring and Tracing
Monitoring ServicesUse OEM Database Maintenance page - Services – Cluster Management Database Services
Set Thresholds per service on elapsed or cpu
Identify notification of alerts via Notification Rules: Service CPU Time (per user call) (microseconds) Service Response Time (per user call) (microseconds)
Tracing Services
execute dbms_monitor.serv_mod_act_trace_enable( - service_name => 'SERV1', - module_name => 'xyz', - (default is all modules)
waits => TRUE, - binds => FALSE);
select * from dba_enabled_traces;
BEGIN DBMS_APPLICATION_INFO.set_module(module_name => 'add_order', action_name => 'insert into orders');END;
Disable:execute dbms_monitor.serv_mod_act_trace_disable( - service_name => 'SERV1', - module_name => 'xyz');
select * from dba_enabled_traces;
To set the module:
Start:
Stopping a Service
Stop a service srvctl stop service -d RACDB -s SERV1
Stop a service and force off connections srvctl stop service -d RACDB -s SERV1 -i RACDB1 -f
Disconnect all sessions for a service: DBMS_SERVICE.DISCONNECT_SESSION(‘SERV1');
Stop a Service
To gracefully take a service offline: Stop the service on an instance to prevent further connections. At a predefined time, disconnect the remaining sessions.
App
App
App
srvctl stop service -d RACDB -s SERV1 DBMS_SERVICE.DISCONNECT_SESSION(‘SERV1');
App
App
App
App
App
Views
Service views:gv$active_services Active services
gv$session Service_name by session
gv$service_stats Stats by service
calls, execute, parse, etc
dba_services goal, failover, etc
gv$servicemetric Goodness and flags
Use group_id=10 for latest entry
Updated every 5 seconds
gv$servicemetric_history Servicemetric history
Contains 1 hour of history
sys.sys$service_metrics_tab LBA advisory events
Updated every 30 secondsHas RLB fan event
Technology for better business outcomes
47 April 11, 2023
While at Oracle OpenWorld….• Visit HP in Moscone South, Booth #1301• Assess your IT environment – for a chance
to win an HP Mini Notebook and donate to Feeding America!−Take the TCO Challenge
−Modernization Impact Quiz
−Storage and Server Assessment
−Adaptive Infrastructure Maturity Model
−ERP Optimization Assessment