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Copyright 2012, Oracle and/or its affiliates. All rights reserved. 1
Oracle Active Data Guard Performance Geovanni Vega Velasquez
Database Brand Manager Oracle Mexico
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 2
Note to viewer
These slides provide various aspects of performance data for
Data Guard and Active Data Guard we are in the process of
updating for Oracle Database 12c.
It can be shared with customers, but is not intended to be a
canned presentation ready to go in its entirety
It provides SCs data that can be used to substantiate Data Guard
performance or to provide focused answers to particular concerns
that may be expressed by customers.
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 3
Note to viewer
See this FAQ for more customer and sales collateral
http://database.us.oracle.com/pls/htmldb/f?p=301:75:1014514610433
66::::P75_ID,P75_AREAID:21704,2
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 4
Agenda Data Guard Performance
Failover and Switchover Timings
SYNC Transport Performance
ASYNC Transport Performance
Primary Performance with Multiple Standby Databases
Redo Transport Compression
Standby Apply Performance
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 5
Data Guard 12.1 Example - Faster Failover
# of database
sessions on primary
and standby
# of database sessions on primary and standby
43 seconds 2,000 sessions
on both primary
and standby
48 seconds 2,000 sessions
on both primary
and standby
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 6
Data Guard 12.1 Example Faster Switchover
# of database
sessions on
primary and
standby
# of database sessions on primary and standby
83 seconds 500 sessions on
both primary and
standby
72 seconds 1,000 sessions on
both primary and
standby
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 7
Agenda Data Guard Performance
Failover and Switchover Timings
SYNC Transport Performance
ASYNC Transport Performance
Primary Performance with Multiple Standby Databases
Redo Transport Compression
Standby Apply Performance
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 8
Synchronous Redo Transport
Primary database performance is impacted by the total round-trip time for
acknowledgement to be received from the standby database
Data Guard NSS process transmits Redo to the standby directly from log buffer, in
parallel with local log file write
Standby receives redo, writes to a standby redo log file (SRL), then returns ACK
Primary receives standby ACK, then acknowledges commit success to app
The following performance tests show the impact of SYNC transport on
primary database using various workloads and latencies
In all cases, transport was able to keep pace with generation no lag
We are working on test data for Fast Sync (SYNCNOAFFIRM) in Oracle
Database 12c (same process as above, but standby acks primary as soon as
redo is received in memory it does not wait for SRL write.
Zero Data Loss
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 9
Test 1) Synchronous Redo Transport
Workload:
Random small inserts (OLTP) to 9 tables with 787 commits per second
132 K redo size, 1368 logical reads, 692 block changes per transaction
Sun Fire X4800 M2 (Exadata X2-8)
1 TB RAM, 64 Cores, Oracle Database 11.2.0.3, Oracle Linux
InfiniBand, seven Exadata cells, Exadata Software 11.2.3.2
Exadata Smart Flash, Smart Flash Logging and Write-Back flash
enabled provided significant gains
OLTP with Random Small Insert < 1ms RTT Network Latency
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 10
Test 1) Synchronous Redo Transport
Local standby,
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Test 2) Synchronous Redo Transport
Exadata X2-8, 2-node RAC database
smart flash logging, smart write back flash
Swingbench OLTP workload
Random DMLs, 1 ms think time, 400 users, 6000+ transactions per
second, 30MB/s peak redo rate (different from test 2)
Transaction profile
5K redo size, 120 logical reads, 30 block changes per transaction
1 and 5ms RTT network latency
Swingbench OLTP Workload with Metro-Area Network Latency
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 12
Test 2) Synchronous Redo Transport
30 MB/s redo
3% impact at
1ms RTT
5% impact at
5ms RTT
Swingbench OLTP Workload with Metro-Area Network Latency
0
1000
2000
3000
4000
5000
6000
Swingbench OLTP
Baseline
No Data Guard
Data Guard SYNC
1ms RTT
Network Latency
Data Guard SYNC
5ms RTT
Network Latency
6363 tps
6151 tps
6077 tps
Transactions
per/second
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 13
Test 3) Synchronous Redo Transport
Exadata X2-8, 2-node RAC database
smart flash logging, smart write back flash
Large insert OLTP workload
180+ transactions per second, 83MB/s peak redo rate, random tables
Transaction profile
440K redo size, 6000 logical reads, 2100 block changes per transaction
1, 2 and 5ms RTT network latency
Large Insert OLTP Workload with Metro-Area Network Latency
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0
50
100
150
200
Test 3) Synchronous Redo Transport
83 MB/s redo
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Test 4) Synchronous Redo Transport
Exadata X2-8, 2-node RAC database
smart flash logging, smart write back flash
Mixed workload with high TPS
Swingbench plus large insert workloads
26000+ txn per second and 112 MB/sec peak redo rate
Transaction profile
4K redo size, 51 logical reads, 22 block changes per transaction
1, 2 and 5ms RTT network latency
Mixed OLTP workload with Metro-Area Network Latency
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 16
No Sync 0ms 2ms 5ms 10ms 20ms
Txns/s 29,496 28,751 27,995 27,581 26,860 26,206
Redo Rate (MB/sec) 116 112 109 107 104 102
% Workload 100% 97% 95% 94% 91% 89%
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
Txn
Rate
R
ed
o R
ate
Test 4) Synchronous Redo Transport Mixed OLTP workload with Metro-Area Network Latency
Swingbench plus large insert
112 MB/s redo
3% impact at < 1ms RTT
5% impact at 2ms RTT
6% impact at 5ms RTT
Note: 0ms latency on graph represents values falling in
the range
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 17
Additional SYNC Configuration Details
No system bottlenecks (CPU, IO or memory) were encountered during
any of the test runs
Primary and standby databases had 4GB online redo logs
Log buffer was set to the maximum of 256MB
OS max TCP socket buffer size set to 128MB on both primary and standby
Oracle Net configured on both sides to send and receive 128MB with an
SDU for 32k
Redo is being shipped over a 10GigE network between the two systems.
Approximately 8-12 checkpoints/log switches are occurring per run
For the Previous Series of Synchronous Transport Tests
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 18
Customer References for SYNC Transport
Fannie Mae Case Study that includes performance data
Other SYNC references
Amazon
Intel
MorphoTrak prior biometrics division of Motorola, case study, podcast, presentation
Enterprise Holdings
Discover Financial Services, podcast, presentation
Paychex
VocaLink
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 19
Synchronous Redo Transport
Redo rates achieved are influenced by network latency, redo-write
size, and commit concurrency in a dynamic relationship with each other that will vary for every environment and application
Test results illustrate how an example workload can scale with minimal
impact to primary database performance
Actual mileage will vary with each application and environment.
Oracle recommends customers conduct their own tests, using their
workload and environment. Oracle tests are not a substitute.
Caveat that Applies to ALL SYNC Performance Comparisons
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 20
Agenda
Failover and Switchover Timings
SYNC Transport Performance
ASYNC Transport Performance
Primary Performance with Multiple Standby Databases
Redo Transport Compression
Standby Apply Performance
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 21
Asynchronous Redo Transport
ASYNC does not wait for primary acknowledgement
A Data Guard NSA process transmits directly from log buffer in parallel with
local log file write
NSA reads from disk (online redo log file) if log buffer is recycled before redo
transmission is completed
ASYNC has minimal impact on primary database performance
Network latency has little, if any, impact on transport throughput
Uses Data Guard 11g streaming protocol & correctly sized TCP send/receive buffers
Performance tests are useful to characterize max redo volume that ASYNC is
able to support without transport lag
Goal is to ship redo as fast as generated without impacting primary performance
Near Zero Data Loss
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 22
Asynchronous Test Configuration
100GB online redo logs
Log buffer set to the maximum of 256MB
OS max TCP socket buffer size set to 128MB on primary and standby
Oracle Net configured on both sides to send and receive 128MB
Read buffer size set to 256 (_log_read_buffer_size=256) and archive buffers
set to 256 (_log_archive_buffers=256) on primary and standby
Redo is shipped over the IB network between primary and standby nodes
(insures that transport is not bandwidth constrained)
Near-zero network latency, approximate throughput of 1200MB/sec.
Details
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 23
ASYNC Redo Transport Performance Test
0
100
200
300
400
500
600
Single Instance
Data Guard ASYNC transport can sustain very
high rates
484 MB/sec on single node
Zero transport lag
Add RAC nodes to scale transport performance
Each node generates its own redo thread and has a
dedicated Data Guard transport process
Performance will scale as nodes are added assuming
adequate CPU, I/O, and network resources
A 10GigE NIC on standby receives data at
maximum of 1.2 GB/second
Standby can be configured to receive redo across two
or more instances
Oracle Database 11.2.
Redo
Transport
MB/sec
484
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 24
Data Guard 11g Streaming Network Protocol
Streaming protocol is new with Data Guard 11g
Test measured throughput with 0 100ms RTT
ASYNC tuning best practices
Set correct TCP send/receive buffer size = 3 x
BDP (bandwidth delay product)
BDP = bandwidth x round-trip network latency
Increase log buffer size if needed to keep NSA
process reading from memory
See support note 951152.1
X$LOGBUF_READHIST to determine buffer hit rate
High Network Latency has Negligible Impact on Network Throughput
0
5
10
15
20
25
30
35
ASYNC
0ms
25ms
50ms
100ms
Redo
Transport
Rate MB/sec
Network
Latency
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 25
Agenda
Failover and Switchover Timings
SYNC Transport Performance
ASYNC Transport Performance
Primary Performance with Multiple Standby Databases
Redo Transport Compression
Standby Apply Performance
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 26
Multi-Standby Configuration
A growing number of customers use multi-standby Data
Guard configurations.
Additional standbys are used for:
Local zero data loss HA failover with remote DR
Rolling maintenance to reduce planned downtime
Offloading backups, reporting, and recovery from primary
Reader farms scale read-only performance
This leads to the question: How is primary database
performance affected as the number of remote transport
destinations increases?
Primary - A Local Standby - B
Remote
Standby - C
SYNC
ASYNC
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 27
Redo Transport in Multi-Standby Configuration
97.0%
98.0%
99.0%
100.0%
101.0%
102.0%
103.0%
104.0%
105.0%
Primary Performance Impact: 14 Asynchronous Transport Destinations
92.0%
94.0%
96.0%
98.0%
100.0%
102.0%
Increase in CPU (compared to baseline)
Change in redo volume (compared to baseline)
0 - 14 destinations 0 -14 destinations
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 28
Redo Transport in Multi-Standby Configuration
96.0%
98.0%
100.0%
102.0%
104.0%
Primary Performance Impact: 1 SYNC and multiple ASYNC Destinations
92.0%
94.0%
96.0%
98.0%
100.0%
102.0%
Increase in CPU (compared to baseline)
Change in redo volume (compared to baseline)
# of SYNC/ASYNC destinations
Zero
1/0 1/1 1/14
# of SYNC/ASYNC destinations
Zero
1/0 1/1 1/14
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 29
Redo Transport for Gap Resolution
Standby databases can be configured to request log files needed to
resolve gaps from other standbys in a multi-standby configuration
A standby database that is local to the primary database is normally
the preferred location to service gap requests
Local standby database are least likely to be impacted by network outages
Other standbys are listed next
The primary database services gap requests only as a last resort
Utilizing a standby for gap resolution avoids any overhead on the primary
database
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 30
Agenda
Failover and Switchover Timings
SYNC Transport Performance
ASYNC Transport Performance
Primary Performance with Multiple Standby Databases
Redo Transport Compression
Standby Apply Performance
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 31
0
500
1000
1500
2000
2500
Redo Transport Compression
Test configuration
12.5 MB/second bandwidth
22 MB/second redo volume
Uncompressed volume exceeds
available bandwidth
Recovery Point Objective (RPO)
impossible to achieve
perpetual increase in transport lag
50% compression ratio results in:
volume < bandwidth = achieve RPO
ratio will vary across workloads
Requires Advanced Compression
Conserve Bandwidth and Improve RPO when Bandwidth Constrained
22 MB/sec uncompressed
12 MB/sec compressed
Elapsed Time - Minutes
Transport Lag - MB
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 32
Agenda
Failover and Switchover Timings
SYNC Transport Performance
ASYNC Transport Performance
Primary Performance with Multiple Standby Databases
Redo Transport Compression
Standby Apply Performance
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 33
Standby Apply Performance Test
Redo apply was first disabled to accumulate a large number of log files
at the standby database. Redo apply was then restarted to evaluate
max apply rate for this workload.
All standby log files were written to disk in Fast Recovery Area
Exadata Write Back Flash Cache increased the redo apply rate from
72MB/second to 174MB/second using test workload (Oracle 11.2.0.3)
Apply rates will vary based upon platform and workload
Achieved volumes do not represent physical limits
They only represent the particular test case configuration and workload,
higher apply rates have been achieved in practice by production customers
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 34
Apply Performance at Standby Database
Test 1: no write-back flash
cache
On Exadata x2-2 quarter rack
Swing bench OLTP workload
72 MB/second apply rate
I/O bound during checkpoints
1,762ms for checkpoint
complete
110ms DB File Parallel Write
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 35
Apply Performance at Standby Database
Test 2: a repeat of the previous
test but with write-back flash
cache enabled
On Exadata x2-2 quarter rack
Swing bench OLTP workload
174 MB/second apply rate
Checkpoint completes in
633ms vs 1,762ms
DB File Parallel Write is
21ms vs 110ms
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 36
Two Production Customer Examples
Thomson-Reuters
Data Warehouse on Exadata, prior to write-back flash cache
While resolving a gap of observed an average apply rate of 580MB/second
Allstate Insurance
Data Warehouse ETL processing resulted in average apply rate over a 3
hour period of 668MB/second, with peaks hitting 900MB/second
Data Guard Redo Apply Performance
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 37
Redo Apply Performance for Different Releases
0
100
200
300
400
500
600
700
OracleDatabase 9i
OracleDatabase
10g
OracleDatabase11g (nonExadata)
OracleDatabase
11g(Exadata)
High End - Batch
High End - OLTP
Range of Observed Apply Rates for Batch and OLTP
Standby
Apply
Rate
MB/sec
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 38
Copyright 2012, Oracle and/or its affiliates. All rights reserved. 39