Oracle Database on Windows: Best Practices and Future Directions Alex Keh Principal Product Manager, Server Technologies, Oracle
Agenda Oracle Database 11g: New Features Supported Operating Systems Database Architecture Best Practices for Windows (32-bit and 64-bit) Diagnosability Optimize CPU usage Optimize Network Optimize File I/O Best Practices for 32-bit Windows Best Practices for 64-bit Windows
<Insert Picture Here> Oracle Database 11g: New Features
Best Price/Performance on Windows #1 TPC-C Price/Performance amongst all platforms Oracle Database 11g on Windows …And Oracle has the #1 TPC-C Performance also TPC-C by Price/Performance 11g SQL 2005 Highest Ranking Benchmark 1st 3rd Price/tpmC $0.73 $0.84 tpmC 102,454 82,774 Publication Date 9/12/07 3/27/07 As of 11/29/07: HP ProLiant ML350G5, 102,454 tpmC, $.73/tpmC available 12/31/07. HP Integrity Superdome Server, 4,092,799 tpmC, $2.93 tpmC, available 8/6/07 (#1 TPC-C performance). Source: Transaction Processing Performance Council (TPC) www.tpc.org
Active Directory and Windows Security Database Registration and Name Resolution Support authenticated connection to Active Directory using OS authentication Kerberos Authentication Stronger encryption algorithms (DES3, AES, RC4) Support default encryption type supported by MS KDC Use DNS Domain Name as Kerberos REALM name by default Kerberos authentication to Oracle database in a MS cross-domain setup Removal of 30 character limit on the Kerberos user name
Oracle VSS Writer Oracle Volume Shadow Copy Service (VSS) writer is transparently integrated with Windows VSS Oracle writer installed automatically with Oracle DB Automatic online point-in-time copy of Oracle database using VSS requestor Simple backup and recovery procedure Offload backup and reporting to another server using transportable snapshots Integrated with Recovery Manager (RMAN) and Flash Recovery area Intelligent post restore operations on restored files E.g. file recovery, instance startup in mount/nomount mode after creating necessary directories Automatic deletion of archive logs that are shadow copied by VSS framework
Direct NFS Client on Windows Network Attached Storage (NAS) use Network File System (NFS) Oracle Database 11g allow direct Windows NFS v3 access Part of DB kernel in Oracle Disk Manager library Common Oracle NFS interface for potentially all host platforms and NFS servers Tailored for the specific I/O patterns that Oracle uses Bypasses a lot of software layers in OS Specially useful for Windows as Kernel NFS is not natively supported on Windows Benefits: faster performance, easier manageability, simplified tuning, and better diagnostics
Direct NFS Linear scalability of direct NFS can be achieved with inexpensive NICs Does not require expensive switches which support link aggregation…Oracle does load balancing rather relying on a switch Parallel network paths – More NICs – more bandwidth Direct NFS is a good solution from low to high end database servers
Grid Control for Microsoft Servers Systematic way to extend system coverage Key Benefit: Centralize Management Enable GC to monitor and manage new components Windows Host Management MOM Connector Microsoft plug-ins: Exchange SQL Server Active Directory .NET Framework IIS
GC for Microsoft Exchange Server New with Grid Control 10.2.0.4 Automatically included with Management Agent No download from OTN Discovery Organization, Routing Groups, Exchange Servers Monitoring Inbound/Outbound MTA/SMTP/Information Store connections Message traffic Inbound/outbound queues Resource usage
GC for Microsoft Exchange Server Reporting Out of the box Configuration Data Exchange Link Exchange Connector Exchange Cluster Resource Active Directory
GC for Microsoft Exchange Server
Management Connector for Microsoft Operations Manager (MOM) Enables selective forwarding of MOM alerts to Enterprise Manager Automatic and manual alert forwarding (using Event Rules and Resolution State) Enterprise Manager is automatically updated when changes in MOM occur Flexible modeling options inside Enterprise Manager Generic MOM Managed Host target Map MOM computers to individual targets in EM Associate MOM alerts with existing EM targets
<Insert Picture Here> Windows Operating Systems Supported
Windows 32-bit Platform Support Operating System 9i R2 10g R1 10g R2 11g Windows 2000 Yes Windows XP Professional Windows Server 2003 Windows Vista No Windows Server 2008 Planned Planned – Latest DB patchset available at the time
Windows 64-bit Platform Support Operating System 9i R2 10g R1 10g R2 11g Windows Server 2003 for Itanium Yes TBD Windows XP & Windows Server 2003, x64 Editions No Windows Vista for x64 systems Planned Windows Server 2008 for x64 Systems Windows Server 2008 for Itanium TBD – To be determined. Will be announced later.
<Insert Picture Here> Oracle Database on Windows Architecture
Architecture: Thread Model Oracle process 3GB or 8TB total Code SGA SGA contains DB buffers, log buffers shared pool, other memory allocations Each thread consists of PGA, stack, Background and foreground threads Oracle on Windows runs as a single process. As depicted in the slide above, all memory For the Oracle RDBMS on Windows comes out of that single process address space. This memory includes: Process overhead (code for oracle.exe) The SGA for the instance All user threads All user PGA memory The process address space on 32-Bit Windows is 4GB. However, Microsoft reserves 2GB for OS kernel memory, leaving a default of 2GB for a user process (eg ‘oracle.exe’). The /3GB boot switch can be added to the boot.ini to change that dynamic and allow A user process to address 3GB of memory (by restricting the OS/kernel to only 1GB of memory). The slide above depicts a 3GB memory limit, assuming that the /3GB switch is in place. This 3GB limit can be a sever limitation on the Oracle RDBMS, and setting this switch can Have consequences on the OS side as well (see Note#297498.1). On 64-Bit platforms, the addressable memory limit per process jumps to 8TB, effectively removing This memory obstacle on Windows platforms.
Database Architecture Thread model Not a straight port of Oracle’s process architecture 3GB (32-bit) or 8TB (64-bit) maximum memory per database instance VLM support allows more than 3GB on 32-bit Runs as a Windows service process No limits on memory, connections, resources except those imposed by the operating system
Oracle Enhancements for Windows Server 2003 Large Page support For instances with large memory requirements, large page support can improve performance Set Registry parameter ORA_LPENABLE to 1 32-bit – 4KB default – 2MB Itanium – 8KB default – 16MB x64 – 8KB default – 2MB NUMA support for memory/scheduling Database intelligently allocates memory and schedules threads based on node configuration Best Practice: For NUMA on AMD patch to a minimum 10.2.0.2 P5
<Insert Picture Here> Best Practices for 32-bit and 64-bit Windows
11g Client Diagnosability Integrated with ADR OCI and Net tracing and logging uses ADR by default Multithreaded client-side diagnosability context support First Failure Capture Client and Server trace file correlation Reduce one-off diagnostic patches Structure Dump Facility
Client Characteristics V$SESSION_CONNECT_INFO/GV$_SESSION_CONNECT_INF CLIENT_CHARSET (NLS character set) CLIENT_CONNECTION (Homogeneous/heterogeneous) CLIENT_OCI_LIBRARY (Home-based, Instant Client Full/Light) CLIENT_VERSION (client RSF version) CLIENT_DRIVER (OCI/JDBC/other) OCI_ATTR_DRIVER_NAME to set third party driver DBAs can look at data dictionary to find out what clients are connecting and what they are using
CPU Tuning Oracle uses all processors available through the OS ORACLE_AFFINITY Registry value can be set to tell Oracle which threads to run on which processors (same setting for all instances) Use Database Resource Manager to set CPU usage for different classes of users For example, one can configure the DB to use 50% CPU for gold customers, 30% for silver, and 20% for rest Thread priorities can be set in the Registry using the ORACLE_PRIORITY variable
CPU Tuning – Diagnosing High CPU Process Explorer: drill down to threads Get thread ID of high CPU thread and then do query SELECT a.spid, b.username FROM v$process a, v$session b WHERE a.addr= b.paddr AND a.spid = <thread number>
Networking Best Practices Use one listener per system The default queue-size for Windows Server is 50 – increase using QUEUESIZE parameter in LISTENER.ORA – prevents errors during login storms Listener Logon Storm Handler Configurable on server side in LISTENER.ORA (RATE_LIMIT = <max conn/sec>) Use only if you have logon storm issues Check Listener log file: if the number of requests per second exceeds the queue-size values, increasing the queue-size recommended.
Networking Best Practices Increase SDU_SIZE in SQLNET.ORA or TNSNAMES.ORA Controls SQL*Net packet size Default SDU_SIZE in 11g is now 8K For bulk data transfer scenarios, increase SDU_SIZE in sqlnet.ora or tnsnames.ora Size can be increased up to 32K Any mix of 11g and 10g clients and servers will set SDU_SIZE to lower of the two peers (pre-11g default is 2K) For 10g, increase SDU_SIZE to 8K or higher Common misperception: Should not be set to match MTU! Check Listener log file: if the number of requests per second exceeds the queue-size values, increasing the queue-size recommended.
Networking Best Practices: Shared Server vs. Dedicated Server Dedicated server gives very best performance Each client connection has it’s own thread Memory usage is 2-4 MB per server thread Oracle uses dedicated server for OLTP benchmarks Can hit scalability limits due to memory use Shared server saves a lot of memory! Idle connections will not consume much memory Latency because dispatcher hands request to shared server Good for large number of connections with many idle
Networking Best Practices: Shared Server vs. Dedicated Server Recommendation Use dedicated server if you have enough physical memory Otherwise, use shared for all sessions that may be idle for some time Continue to use dedicated server for a small number of high performance connections/queries
Networking Best Practices: Using Shared Server Client connections share pre-spawned server threads No dedicated idle threads wasting resources Enable Shared Server on client in tnsnames.ora: (DESCRIPTION= (ADDRESS=(PROTOCOL=tcp) (HOST=sales-server)(PORT=1521)) (CONNECT_DATA= (SERVICE_NAME=sales.us.acme.com) (SERVER=shared) )) Modify init.ora parameters on server to enable shared servers Rough guidelines: 20 or 30 Shared Servers per 500 sessions, then tune from there Use 1 dispatcher for every 50-100 sessions See Net Admin Guide for more details
Networking Best Practices: Database Resident Connection Pool Pools Oracle Dedicated Servers Shares server side connection pool across mid tier systems and processes Co-exists in all server configurations Dedicated Servers, Shared Servers, RAC Most useful when you have many thousands of client processes connecting to a database server and each process needs to hold on to the database server session for a short time In test environment, we were able to support more than 10,000 connections to a 2 GB Database Server Pooling is optionally enabled by DBA on Server Client connect string also needs to have (SERVER=POOLED)
Networking Best Practices: Connection Timeouts Client Side connection timeouts: Achieve fast failover when you have multiple addresses in connect string TCP.CONNECT_TIMEOUT – 11g feature - it can be a few seconds – Not set by default SQLNET.OUTBOUND_CONNECT_TIMEOUT – 10gR2 and later – Not set by default These two timeouts can be used individually or at the same time Server Side connection timeouts: SQLNET.INBOUND_CONNECT_TIMEOUT – 10gR1 and later - default 60 secs for 10gR2 and 11g, not enabled by default for 10gR1 Can also be used along with the client side timeouts above Check Listener log file: if the number of requests per second exceeds the queue-size values, increasing the queue-size recommended.
Networking Best Practices SQLNET.AUTHENTICATION_SERVICES=(NTS) This is a default value in SQLNET.ORA, needed for OS authentication (connect / as SYSDBA) It should be left at default on server side Use SecureFile LOBs NET stack optimizations provide very high throughput limited only by the underlying hardware Check Listener log file: if the number of requests per second exceeds the queue-size values, increasing the queue-size recommended.
File System Best Practices Use ASM – whether single-instance or RAC – use 10.1.0.4 or higher Benefits Don’t need to move datafiles around Don’t need to take tablespaces offline Add disks with no downtime Check Listener log file: if the number of requests per second exceeds the queue-size values, increasing the queue-size recommended.
Memory Best Practices 11g: Use MEMORY_TARGET for automatic management of combined SGA and PGA 10g and earlier: Control SGA Memory by using SGA_TARGET parameter Control PGA Memory by using PGA_AGGREGATE_TARGET parameter
<Insert Picture Here> Best Practices for 32-bit Windows
32-bit Memory Best Practices Increase addressable memory available to the Oracle process by adding /3GB switch to boot.ini file: multi(0)disk(0)rdisk(0)partition(1)\WINNT="Microsoft Windows 2000 Advanced Server" /fastdetect /3GB Reboot server to enable Must monitor kernel memory closely to prevent instability of operating system See Metalink Notes 46001.1 and 297498.1 See Microsoft KB article 297812
Monitoring Memory Key Items to Monitor for Memory Usage: Perfmon - Virtual Bytes for oracle.exe to see total memory used by the process Total Pool Non-Paged Bytes – Memory Counter If grows close to 128MB, operating system instability will occur If this grows too high, look for memory leaks Free System Page Table Entries (PTE’s) – Memory Counter Should never fall below 7500 or so /USERVA=2560 switch in boot.ini will help prevent this
Using ORASTACK Each thread within Oracle process is provided 1 MB reserved stack space Reduce to 500 KB without consequence on most systems: C:\ orastack tnslsnr.exe 500000 C:\ orastack oracle.exe 500000 Be sure to run on BOTH tnslsnr.exe and oracle.exe Stop processes before running Orastack If you apply a patch, you must re-run Orastack Make sure to test your system to be sure 500 KB is OK See Metalink Note 46001.1 for more information
32-bit: VLM Support Rest of Windows Server 2003 RAM SGA Code Rest of RAM For O/S, other apps 3GB Windows Server 2003 Memory Limits (32-bit) Standard Edition: 4GB Enterprise Edition: 32GB Datacenter Edition: 64GB database threads/ memory In 32-Bit Windows, even though a single process can only address up to 4GB of RAM, it is still possible to have Much more RAM than that on a single machine. The slide above depicts the total memory supported by different flavors Of the Windows 2003 operating system. On machines that have more than 4GB of RAM, this memory can still be Taken advantage of by multiple processes, as each process has its own separate address space. This means that If you have two different Oracle instances, each will have its own ‘oracle.exe’, and each oracle.exe will be able to Separately address its own 3GB of user address space. Aside from this, it is also possible for a single process (single oracle.exe) to address memory beyond its 4GB Limit by taking advantage of VLM (Very Large Memory) support on Windows. This is also known as Address Windowing Extensions, or AWE.
32-bit: VLM Support Extended memory available for DB buffers via AWE calls Memory from AWE calls used for DB buffers only. The amount of AWE memory allocated equals db_block_size times db_block_buffers. Rest of RAM For O/S, other apps Window on DB buffers in AWE mem Oracle operating system process. Normally limited to 3GB of address space. With VLM, Oracle can get up to 12GB of database buffers. 3GB Oracle takes advantage of Address Windowing Extensions by allowing the database block buffers to Be accessed indirectly through a window in the 3GB address space. The size of this window in the 3GB address Space is defined by the Oracle Registry value: AWE_WINDOW_MEMORY, which defaults to 1GB. Through this window, the rest of the buffer cache, which can be up to 64GB, can be mapped from the extended area of memory. Note#225349.1 discusses the implementation of VLM/AWE on Windows in more detail. SGA minus DB buffers Code
Implementing AWE Use AWE with Oracle by adding initialization parameter USE_INDIRECT_DATA_BUFFERS Use DB_BLOCK_BUFFERS instead of DB_CACHE_SIZE With AWE, database buffer cache can be increased up to roughly 12 GB Default value for AWE_WINDOW_MEMORY is 1 GB See Metalink Note 225349.1 for more information
Best Practices for 32-Bit Memory Use Automatic Workload Repository (AWR) to monitor cache hit ratios and shared_pool stats, etc. Make sure that values are not too high When implementing AWE be aware that using AWE disables Automatic Memory Management features (SGA_TARGET cannot be used when USE_INDIRECT_DATA_BUFFERS is set).
<Insert Picture Here> Best Practices for 64-bit Windows
64-bit Best Practices Use SP 2 for Windows Server 2003 to avoid Windows performance bug Run correct 64-bit version of Oracle for the architecture i.e. 64-bit Oracle for AMD64/EM64T or 64-bit Oracle for Itanium 32-Bit Oracle DB not supported on 64-bit platforms 32-bit client is supported on Windows x64 Enable Large Pages
Oracle on Windows Customers “ “ “ “ “ “ We've tested a 23-node [Oracle] RAC cluster in a Windows environment without any issues. With Oracle we were able to provide best-in-class performance while deploying a system that has increased our capabilities significantly Oracle has a more scalable and reliable database product... As a result, we've achieved high-end clustering capabilities for a relatively low cost ” “ Thanks to Oracle Enterprise Manager Grid Control, one person is able to manage all of the databases in all of the data centers. ` ” ” ” Daniel Beuoy, Director of DB Technology Russ Donnan, CIO Pete Goutmann, Vice President, Technology Russ Donnan, CIO
More Information Windows Server Center Windows and .NET Blog http://otn.oracle.com/windows Windows and .NET Blog http://cshay.blogspot.com/ For more questions alex.keh@oracle.com
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