Independent consultant. (Ex-) Oracle ACE Director. Member of OakTable Network. Performance Troubleshooting In-house workshops

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2 Independent consultant Performance Troubleshooting In-house workshops Cost-Based Optimizer Performance By Design (Ex-) Oracle ACE Director Alumni Member of OakTable Network

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6 Oracle Cloud extended trial license as part of Oracle ACE Director program Trial license comes with limitations / resource quotas: - 1TB max storage - max 6 OCPUs (more details later) - max 5 IP Endpoints Performance tests conducted within these limits

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12 No hardware performance difference between different editions measurable all created services show similar performance characteristics in terms of CPU and I/O capabilities Different performance still possible on software level Diagnostic + Tuning Pack features (e.g. SQL Tuning advisor), InMemory Column Store etc.

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17 Services can be scaled by adding more CPUs, RAM and storage Currently no online operation, other Cloud providers can do some of these scaling activities online

18 Tablespace encryption mandatory Network access rules, by default public access disabled, only access via SSH possible

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23 4 OCPUs configuration

24 Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 8 On-line CPU(s) list: 0-7 Thread(s) per core: 2 Core(s) per socket: 4 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 79 Model name: Intel(R) Xeon(R) CPU E GHz Stepping: 1 CPU MHz: BogoMIPS: Hypervisor vendor: Xen Virtualization type: full L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 46080K NUMA node0 CPU(s): 0-7

25 ORACLE DBAAS AMAZON RDS AVG_DURATION AVG_DURATION SQLLIO4 29,9 SQLLIO4 22,7 SQLLIO8 31,1 SQLLIO8 47,4 PLSQL4 34 PLSQL4 36 PLSQL8 35,8 PLSQL8 60, Average duration of a CPU bound database operation, running 4 and 8 threads SQLLIO: Burns CPU via SQL logical I/Os (SQL engine) PLSQL: Burns CPU via PL/SQL computation (PL/SQL engine)

26 Disks exposed via XEN disk storage devices (paravirtualized XEN disk drivers /dev/xvd*) and then via device mapper and LVM Single Instance: ext4 Filesystem, asynchronous and direct I/O enabled by default RAC: ASM plus ACFS on top

27 Average read IOPS figures over several days 4 / 8 threads, 4KB/8KB/16KB blocksize, maximum physical, asynchronous I/O Single Instance 4 OCPUs / 8 Cores/Threads RAC Two Instances OCPUs / Cores/Threads TEST AVG_IOPS TEST AVG_IOPS 4THREADS_4K THREADS_4K THREADS_8K THREADS_8K THREADS_16K THREADS_16K THREADS_4K THREADS_4K THREADS_8K THREADS_8K THREADS_16K THREADS_16K 40330

28 General Purpose SSD: Less than 1TB allocated: Peak: IOPS for max. 30 minutes Then throttled to something between 100 IOPS and less than IOPS depending on amount of storage allocated I/O credits re-load over time, determine the possible IOPS peak between baseline and IOPS Provisioned IOPS: Maximum IOPS

29 Premium SSD: Maximum IOPS per storage container

30 IOPS / throughput independent from allocated storage size (tested with 25GB to 1TB)!! Compare this to Amazon RDS where you need at least 3TB of storage to get maximum IOPS for Provisioned IOPS premium storage

31 Maximum throughput Single instance: 640MB / sec read 120MB / sec write Two instances RAC: 1100MB / sec read 80MB / sec write

32 I/O Latency - Synchronous I/O 8KB blocksize / 8 threads ( db file sequential read ) WAIT_TIME COUNT PERCENT PERCENT_GRAPH <= 256 microseconds ,1 <= 512 microseconds ,1 ################# <= 1 millisecond ,2 ###### <= 2 milliseconds ,5 <= 4 milliseconds <= 8 milliseconds <= 16 milliseconds <= 32 milliseconds <= 65 milliseconds 73 0 <= 131 milliseconds 20 0 <= 262 milliseconds 16 0

33 I/O Latency General Purpose SSD - Synchronous I/O 8KB blocksize / 8 threads ( db file sequential read ) WAIT_TIME COUNT PERCENT PERCENT_GRAPH <= 256 microseconds <= 512 microseconds ,4 <= 1 millisecond ,1 <= 2 milliseconds ,4 <= 4 milliseconds ################ <= 8 milliseconds ,1 <= 16 milliseconds ,1

34 Four different tests performed over several days - PL/SQL CPU burning loop (PL/SQL engine) - SQL logical I/O CPU burning - Maximum physical asynchronous I/O - read - Maximum physical asynchronous I/O - write Comparison to dedicated physical host, four cores, Samsung SSD vs. Oracle DBaaS eight cores

35 Test 1: PL/SQL CPU burning loop, executed as many times as CPUs available declare n number; begin loop n := 0; for i in loop n := n + 1; end loop; insert into timings(testtype, thread_id, ts) values ('PLSQL', &thread_id, systimestamp); commit; end loop; end; /

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37 DBaaS per day: Physical host per day:

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39 Test 2: SQL logical I/O CPU burning, executed as many times as CPUs available alter session set "_old_connect_by_enabled" = true; declare n number; begin loop select count(*) X into n from kill_cpu&tabname connect by n > prior n start with n = 1; insert into timings(testtype, thread_id, ts) values ('SQLLIO', &thread_id, systimestamp); commit; end loop; end; /

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43 Test 3: Maximum physical asynchronous I/O read only, minimum buffer cache, CPU times declare n number; begin loop select /*+ leading(t_o) use_nl(t_i) index(t_o) index(t_i) */ sum(t_i.n) into n from t_o, t_i&tabname t_i where t_o.id_fk = t_i.id; insert into timings(testtype, thread_id, ts) values ('&testtype', &thread_id, systimestamp); commit; end loop; end; /

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47 Test 4: Maximum physical asynchronous I/O read-write, minimum buffer cache, CPU times begin loop for rec in ( select /*+ index(t_o) */ id_fk from t_o ) loop update t_i&tabname t_i set n = rec.id_fk where id = rec.id_fk; end loop; insert into timings(testtype, thread_id, ts) values ('&testtype', &thread_id, systimestamp); commit; end loop; end; /

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51 DBaaS events: Physical host events:

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53 Q & A

54 I/O Latency - Synchronous I/O 16KB blocksize / 8 threads ( db file sequential read ) WAIT_TIME COUNT PERCENT PERCENT_GRAPH <= 256 microseconds ,3 <= 512 microseconds ,6 ############## <= 1 millisecond ,3 ############### <= 2 milliseconds # <= 4 milliseconds ,9 <= 8 milliseconds <= 16 milliseconds <= 32 milliseconds <= 65 milliseconds 72 0 <= 131 milliseconds 31 0 <= 262 milliseconds 5 0 <= 1 second 2 0