best practices for speeding and scaling - oracle.com · client-side java database access 23 jdbc...

Copyright©2017, Oracleand/oritsaffiliates.Allrightsreserved.|

BestPracticesforSpeedingandScalingJavaApplicationsOracleDatabase18

Nirmala Sundarappa,PrincipalProductManagerKuassi Mensah, DirectorofProductManagement,JeanDeLavarene,DirectorofDevelopmentServerTechnologies,October5th,2017


SafeHarborStatementThefollowingisintended tooutline ourgeneralproductdirection. Itisintended forinformationpurposes only,andmaynotbe incorporatedintoanycontract.Itisnotacommitment todeliver anymaterial,code,orfunctionality,andshouldnotberelieduponinmakingpurchasingdecisions. Thedevelopment, release, andtimingofanyfeaturesorfunctionality described forOracle’sproductsremainsatthesolediscretion ofOracle.

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ProgramAgenda

What’sNew?

SpeedingUpJavaapplications

ScalingtheJavaworkloads

Questions

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ProgramAgenda

What’sNew?


ScalingtheJavaworkloads

Questions

1

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3

4

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Copyright©2017, Oracleand/oritsaffiliates.Allrightsreserved.

OracleDatabase18c

DB18relatedcapabilitieswillbeupdatedoncetheDatabase18cisreleased.Pleasestaytuned.

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DatabaseDevelopment

DatabaseCloudServicesforEnterprise

Exadata CSDatabaseCSExpressCS

Highest availability, scalability andperformance

SMB&Departmental Applications

Enterprise Applications

OracleCloudInfra

CustomeratCloudChoices Exadata CloudMachineCloudMachine

100%compatiblefromentry-leveltothelargestmissioncriticaldataloads


JavaConnectivitytoDatabaseServicesonCloud

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• OracleExadata ExpressService(EECS)– TCPSconnectionwithOraclewalletsorJKS

– Needclient_credentials.zipfromserviceconsole

• OracleDatabaseCloudService(DBCS)– TCPconnection– 1521needs tobeunblocked

• OracleDatabaseExadataCloudMachine(ExaCM)– TCPconnection– Everything ispre-setup

• OracleDatabaseCloudInfrastructure(OCI)– TCPconnection– Add1521tosecurity list


ProgramAgenda

What’sNew?


ScalingJavaapplications

Questions

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BestPracticesforSpeedingUpJavaApplications• UseConnectionURLwithconnectiondescriptors• UseUniversalConnectionPool(UCP)• Tuneexcessivehardparsing• Tuneexcessivesoftparsing• Enforceresultsetcaching• UseLOBBestPractices

• UseArrayoperations(Fetch,DML)• UseJavaintheDatabase• UseNetworkcompressionoverWAN• UseMemorymanagementbestpractices• Lightweight ConnectionValidation

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ConnectionURLwithConnectionDescriptors

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OracleRACwithADG

alias=(DESCRIPTION=(CONNECT_TIMEOUT=90) (RETRY_COUNT=20)(RETRY_DELAY=3)

(TRANSPORT_CONNECT_TIMEOUT=3)(ADDRESS_LIST=

(LOAD_BALANCE=on)(ADDRESS=(PROTOCOL=TCP)(HOST=primary-scan)(PORT=1521)))

(ADDRESS_LIST=(LOAD_BALANCE=on)(ADDRESS=(PROTOCOL=TCP)(HOST=secondary-scan)(PORT=1521)))

(CONNECT_DATA=(SERVICE_NAME =gold-cloud)))

NorelianceonDNS

AutomaticRetries

ALWAYSuseaSERVICEthatisNOTDB/PDBname


ConnectionURL– BestPractices• AlwaysusethelatestversionofJDBCdriverandUCPagainstcurrentorearlierdatabaseversion• Donotmixuptheversionsofjars– Useojdbc8.jar,ucp.jar,andons.jar from12.2.0.1version

• Alwaysreturnconnectionstothepoolforstableconnectionusage,runtimebalancing,andplanneddraining

• ConnectionURLbestpractices– UseoneDESCRIPTIONandmorecancause longdelays– SetLOAD_BALANCE onperADDRESS_LISTtobalanceSCANs– DONOTUSERETRY_COUNT withoutRETRY_DELAY– DOnotuseEasyConnectURL– ithasnoHAcapabilities

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Copyright©2017, Oracleand/oritsaffiliates.Allrightsreserved.

UniversalConnectionPool(UCP)

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UCPProperties Description

setInitialPoolSize(),setMinPoolSize(),setMaxPoolSize()

Set poolsizebasedondatabaseserverresources(numberofcores)Eg:MaxPoolSize =(rdbms-cores *n)/sum (pools-per-mid-tier)

setTimoutCheckInterval(int)setTimeToLiveConnectionTimeout(),setAbandonConnectionTimeout(),setConnectionWaitTimeout(int)setInactiveConnectionTimeout(int)

SettheConnection Timeoutsufficiently highenough tosuitetheapplicationprofile.

setMaxStatements() EnableStatementCaching– BydefaultitisOFF

setFastConnectionFailoverEnabled(),setONSConfiguration()

For HighAvailabilityFeatures.Enabledbydefaultin12.2UCP

Thebestconfiguredconnectionpoolsresultinhigherthroughput


ExcessiveHardStatementParsing?

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Hardparse:allsteps involvedincreatingaSQLstatement parsetreeMonitorhardparseswithAWR/ADDM


Tuneexcessivehardparsing• AvoidHardParsingusingPreparedStatement&BindVariables

Insteadof:String query = "SELECT EMPLOYEE_ID, LAST_NAME, SALARY FROM EMPLOYEES WHERE EMPLOYEE_ID = " + generateNumber(); prepStmt = connection.prepareStatement(query); resultSet = pstmt.executeQuery();

Changeto:String query = "SELECT EMPLOYEE_ID, LAST_NAME, SALARY FROM EMPLOYEES WHERE EMPLOYEE_ID = ?"; prepStmt = connection.prepareStatement(query);prepStmt.setInt(1, generateNumber()); resultSet = pstmt.executeQuery();

Fallback ifapplication cannotbechangedtousebindsinit.ora parameter:CURSOR_SHARING={FORCE|SIMILAR|EXACT}

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Tuneexcessivesoftparsing• EnableStatementcaching– oracleDataSource.setImplicitCachingEnabled(true)

• Choosetherightcachesizetobestutilizethememory– connection.setStatementCacheSize(10)– Trytobeclosertothenumberofmostusedstatements– Defaultstatement cachesizeis10

• Fallback ifyoucannotchangetheapplicationtousestatementcaching– session_cached_cursors =50

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EnforceresultsetcachingServersideresultsetcaching• Querynotre-executed (untilcacheinvalidated)

Clientsideresult-setcaching• Sharedacrossmultiple connections fromthesameDataSourceinthemiddletier

• Fasteraccess tofrequentlyqueried data• Transparent invalidation throughQueryChangeNotification

• Someofthebenchmarks showed3ximprovement

• Serversideconfiguration(init.ora)toenableResult SetCaching– CLIENT_RESULT_CACHE_SIZE– settoclientresultsetcachesize– CLIENT_RESULT_CACHE_LAG – Specifiesclientresultcachelaginminutes

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UseLOBbestpractices• ConvertLOBtoLONGusingdefineColumnType(index,type,size)• TuneSessionDataUnit (SDU)forlargeLOBs,XML,largeResult sets– Max:2MB(12c),64K(11.2),32K(pre-11.2)

– Setonbothserverandclientside(SQLNet.ORA,TNSNAMES.ORAorURL)

– jdbc:oracle:thin:@(DESCRIPTION=(SDU=11280)(ADDRESS=(PROTOCOL=tcp)(HOST=myhost-vip)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=myorcldbservicename)))

– Improvesperformance,networkutilization,andmemoryconsumption• UsePreFetching forsmallLOBssetLobPrefetchsize()

• DataInterface– StreamlinedmechanismforwritingandreadingtheentireLOBcontentsusingthestandardJDBCmethodsgetString()andsetBytes()

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UseSecureFiles LOBs• Largereads/writes– BASICLOBs:internalbuffercopyareexpensive– SECUREFILELOBS:”oracle.net.useZeroCopyIO” or“Vectoredi/omechanism”

• Transparenttoexisting APIs– Usepublic boolean isSecureFile() throws SQLException tocheckwhetherornotyour BLOB or CLOB datausesOracleSecureFile storage

• Compression, encryption,deduplication

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setupSecureFile()

Blob.getBytes()

Fetch/StreamLOBdatadirectly(bypassinternalbuffer)

ResultSet


ArrayDML/Fetching/Prefetching

• Usearrayoperationsinsteadofsinglerowoperations– SinglerowDMLs/fetches incurexcessive roundtrips– Default fetchsizeis10

• Checkifarraysizeislargeenough• Somedriverssupportprefetchinginsteadofarrayfetching

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BestPractices


ArrayFetchinginJavaString query = "SELECT EMPLOYEE_ID, LAST_NAME FROM EMPLOYEES ”

+" WHERE EMPLOYEE_ID > ? ”+" ORDER BY EMPLOYEE_ID”;

pstmt = connection.prepareStatement(query);pstmt.setInt(1, generateNumber());pstmt.setFetchSize(20);rs = pstmt.executeQuery();ResultSetMetaData rsmd = rs.getMetaData();int columnCount = rsmd.getColumnCount();while (rs.next()) {for(int i = 1; i <= columnCount; ++i)

System.out.println(rsmd.getColumnName(i) +”+rsmd.getColumnTypeName(i) +"]: "+rs.getString(i));

}


ArrayDMLinJavaString dml = "UPDATE EMPLOYEES SET SALARY = ?”

+" WHERE EMPLOYEE_ID = ?”;pstmt = connection.prepareStatement(dml);for(int i = 0; i < NUM_ROWS_TO_INSERT; ++i) {

int empId = getEmployeeId(employeeIdList);pstmt.setInt(1, getNewSalary(empId));pstmt.setInt(2, empId);pstmt.addBatch();

}

pstmt.sendBatch();


Client-sideJavaDatabaseAccess

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JDBCSQL

SQL

SQL

•Multiple NetworkexchangeforprocessingeachSQLstatements

• Could leadtohighlatency in WANorCloudenvironments


JavaintheDatabase

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JDBC(internal)SQL

SQL

SQLSQL

• Onecall fortheentireprocedure

• Lownetworklatencyin WANorCloudenvironments

• CanbeconsumedbySQL,PL/SQLoranyclient


NetworkCompressionOverWANMixedData

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• Query:Select *fromTable;

• Data:Five columns50bytes perrow1million rows

• ArraySize:5000

• ConnectionProperty:oracle.net.networkCompression=”on”

• ReducesthesizeofSDUtransmittedacrossthenetwork 0

10

20

30

40

50

60

70

580 100 50 10

Tim

e (s

ec)

Bandwidth (Mbps)

OFFLOWHIGH


MemoryManagementTips• Memoryissueiscausedduetothebuffersusedtostorequeryresults–MoredynamicbuffermechanismandreturnbufferstothecachewhentheResultSetisclosed

– CREATE TABLE TAB(IDNUMBER(10), NAMEVARCHAR2(40),DOBDATE)ResultSet r=stmt.executeQuery(“SELECT ID,NAME,DOBFROMTAB”);

• Managethememoryusedbybuffers– FormQueries carefully(Retrievecolumnsexplicitlyandavoidselect*fromemployees)– Setthefetchsize carefully(avoidsettinghighersetFectchSize(10000))

• UsePreparedStatements andenableImplicitStatementCaches• ControlthememoryheapofJVMusing–Xmx or–Xms

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ProgramAgenda

What’sNew?

SpeedingUpJavaApplications

ScalingJavaApplications

Questions

3

1

2

4

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ScalingJavaApplications• UsingServerSideConnectionPool(DRCP)• HorizontallyScalingJavaWorkload• UsingRuntimeLoadBalancing(RLB)

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UsingServersideconnectionPool(DRCP)• DRCPistheserversideconnectionpoolsharedacrossmanymid-tiers• EnablingDRCPontheserverside– dbms_connection_pool.start_pool();

• ChangetheconnectionURLtoenableDRCP– Eg:,jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(HOST=myhost)(PORT=1521)(PROTOCOL=tcp))(CONNECT_DATA=(SERVICE_NAME=myorcldbservicename))(SERVER=POOLED)))”;

• DRCPTagging– Associateaconnectiontoamid-tierwithaparticulartagnametoretrieveaspecificsessioneasily.–Enableusingthepropertyoracle.jdbc.UseDRCPMultipletag = true

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HorizontalScalingJavaWorkloads

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SHARD A SHARDB SHARD C

SharedConnection

Pool

SingleUnsharded Database


ScalingJavaapplications• SessionbasedShardingviaShardingKey• ShardingAPIs– JDBC/UCP• UCPasaShardDirector

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CoordinatorDB

ApplicationTier

RoutingTier

DatabaseTier

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Session-BasedRoutingviaShardingKey

ShardingKey: Apartitioning keyforasharded table.- E.g:custid- shard keyused forpartitioning thetable‘customers’.

SuperShardingKey:Required incaseofcomposite sharding.

ShardDirector:Looksupsharding keyandredirectstorightshardcontainingthedata.

ApplicationServer

ShardDirector


Sharding APIs:JDBC/UCP

// Sharding Key is a compound key of 2 sub-keysOracleShardingKey shardingKey =

dataSource.createShardingKeyBuilder() .subkey("Customer_EMAIL", oracle.jdbc.OracleType.VARCHAR2)

.subkey("1234", oracle.jdbc.OracleTypes.NUMBER)

.build();

// Super Sharding Key with only one sub-key

OracleShardingKey superShardingKey =dataSource.createShardingKeyBuilder()

.subkey("Customer_Location_US”,oracle.jdbc.OracleType.VARCHAR2)

.build();

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BuildingSharding KeyandSuperSharding Key


OracleJDBCDriver

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OracleUniversalConnectionPool(UCP)

JDBC/UCPconnectionwithaShardingKey

OracleDataSource ods = new OracleDataSource();

// Set connection properties

ods.setURL(DB_URL);ods.setUser("hr");ods.setPassword("****");// Get an Oracle JDBC connection for a shard

Connection conn = ods.createConnectionBuilder()

.shardingKey(shardingKey)

.superShardingKey(superShardingKey)

.build();

PoolDataSource pds = PoolDataSourceFactory.getPoolDataSource();// Set Connection Pool propertiespds.setURL(DB_URL);pds.setUser("hr"); pds.setPassword("****");pds.setInitialPoolSize(10);pds.setMinPoolSize(20);pds.setMaxPoolSize(30);// Get an UCP connection for a shard

Connection conn = pds.createConnectionBuilder()

.shardingKey(shardingKey)

.superShardingKey (superShardingKey)

.build();


GetconnectionShardkey=35

UCPLearningShardTopology§ During pool initialization (orwhen thepool connects tonewer

instances) theshard topology iscollected from various shard tocreateaShardRouting Table

UCP

Shard 1

1-- 10 Chunk 1 Shard 1

Shard 2

Shard 3

Shard 4

GSMlistener

Shard KeysRange ChunkName Shards


10 -- 20 Chunk 2 Shard 21-- 10 Chunk 1 Shard 1

10 -- 20 Chunk 2 Shard 2






GetconnectionShardkey=5GetconnectionShardkey=15

GetconnectionShardkey=25

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UCPasaShardDirector• Once therequired topology iscollected byUCP, connectionrequests canbedirectly serviced bythepool without goingthrough theshard director.

• Basedontheshard keys provided intheconnection request, UCPcanlookup thecorresponding shard onwhich keys existandpooled connections totheshard canbeefficiently reused.

UCP

Shard 1

Shard KeysRange ChunkName Shards




30– 40 Chunk 4 Shard 4

Shard 2

Shard 3

Shard 4

GSMListener

GetconnectionShardkey=16Getconnection

Shardkey=38

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RuntimeLoadBalancing• LeverageLoadBalancingAdvisory– UsedtobalancetheworkacrosstheRACinstances. – Determine the instancethatoffersthebestperformance– Establish connections basedontheadvisory

• UCPusesRACLoadBalancingAdvisoryanddistributestheloadequallyamongtheinstances.• ServicegoalsmustbesettoSERVICE_TIMEorTHROUGHPUT– srvctl modifyservice-db <db_name> -service<service_name> -rlbgoalSERVICE_TIME -clbgoal SHORT

– srvctl modifyservice-db <db_name> -service <service_name> -rlbgoalTHROUGHPUT -clbgoal SHORT

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ProgramAgendawithHighlight

What’sNew?

SpeedingUpJavaApplications

ScalingJavaApplications

Questions4

1

2

3

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Whitepapersandotherresources• Performance,Scalability,andHigh-AvailabilitywithJDBCandUCPinOracleDatabase12cReleas1(12.2.0.1)• GithubCodesampleslocation• JDBC/UCPBlogsite• JDBC&UCPDownloadpage• JDBC&UCPLandingpageforotherresources

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best practices for speeding and scaling - oracle.com · client-side java database access 23 jdbc...

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