1 What is Required?

Learn about the requirements for the system and database resources that support Oracle GoldenGate.

Topics:

• Verifying Certification and System Requirements
  
• Operating System Requirements
  
• Understanding and Obtaining the Oracle GoldenGate Distribution
  

1.1 Verifying Certification and System Requirements

Make sure that you install your product on a supported hardware or software configuration. For more information, see the certification document for your release on the Oracle Fusion Middleware Supported System Configurations page.

Oracle has tested and verified the performance of your product on all certified systems and environments; whenever new certifications occur, they are added to the proper certification document right away. New certifications can occur at any time, and for this reason the certification documents are kept outside of the documentation libraries on the Oracle Technology Network.

1.2 Operating System Requirements

This section outlines the operating system resources that are necessary to support Oracle GoldenGate.

• Memory Requirements
  
• Disk Requirements
  
• Network
  
• Operating System Privileges
  
• Other Operating System Requirements
  
• Additional Considerations
  
• Installing the Oracle GoldenGate Files
  
• Windows Console Character Sets
  

1.2.1 Memory Requirements

All Platforms

The amount of memory that is required for Oracle GoldenGate depends on the amount of data being processed, the number of Oracle GoldenGate processes running, the amount of RAM available to Oracle GoldenGate, and the amount of disk space that is available to Oracle GoldenGate for storing pages of RAM temporarily on disk when the operating system needs to free up RAM (typically when a low watermark is reached). This temporary storage of RAM to disk is commonly known as swapping or paging (herein referred to as swapping). Depending on the platform, the term swap space can be a swap partition, a swap file, a page file (Windows) or a shared memory segment (IBM for i).

Modern servers have sufficient RAM combined with sufficient swap space and memory management systems to run Oracle GoldenGate. However, increasing the amount of RAM available to Oracle GoldenGate may significantly improve its performance, as well as that of the system in general.

Typical Oracle GoldenGate installations provide RAM in multiples of gigabytes to prevent excessive swapping of RAM pages to disk. The more contention there is for RAM the more swap space that is used.

Excessive swapping to disk causes performance issues for the Extract process in particular, because it must store data from each open transaction until a commit record is received. If Oracle GoldenGate runs on the same system as the database, the amount of RAM that is available becomes critical to the performance of both.

RAM and swap usage are controlled by the operating system, not the Oracle GoldenGate processes. The Oracle GoldenGate cache manager takes advantage of the memory management functions of the operating system to ensure that the Oracle GoldenGate processes work in a sustained and efficient manner. In most cases, users need not change the default Oracle GoldenGate memory management configuration.

For more information about evaluating Oracle GoldenGate memory requirements, see the CACHEMGR parameter in the Reference for Oracle GoldenGate. Also, see Tuning the Performance of Oracle GoldenGate in Administering Oracle GoldenGate.

Windows Platforms

For Windows Server environments, the number of process groups that can be run are tightly coupled to the non-interactive Windows desktop heap memory settings. The default settings for Windows desktop heap may be enough to run very small numbers of process groups. As you approach larger amounts of process groups, more than 60 or so, you have two choices:

• Adjust the non-interactive value of the SharedSection field in the registry based on information from Microsoft (Windows desktop heap memory).

• Increase the number of Oracle GoldenGate homes and spread the total number of desired process groups across these homes.

For more information on modifying the Windows Desktop Heap memory, review the following Oracle Knowledge Base document (Doc ID 2056225.1).

1.2.2 Disk Requirements

Disk space requirements vary based on the platform, database, and Oracle GoldenGate architecture to be installed.

• Disk Requirements for Oracle GoldenGate Installation Files
  
• Temporary Disk Requirements
  
• Other Disk Space Considerations
  

1.2.2.1 Disk Requirements for Oracle GoldenGate Installation Files

The disk space requirements for a Oracle GoldenGate installation vary based on your operating system and database. You should ensure that you have adequate disk space for the downloaded file, expanded files, and installed files, which can be up to 2GB.

1.2.2.2 Temporary Disk Requirements

By default, the Oracle GoldenGate Classic Architecture maintains data that it writes to disk in the dirtmp sub-directory of the Oracle GoldenGate installation directory. When total cached transaction data exceeds the CACHESIZE setting of the CACHEMGR parameter, Extract will begin writing cache data to temporary files. The cache manager assumes that all of the free space on the file system is available. This directory can fill up quickly if there is a large transaction volume with large transaction sizes. To prevent I/O contention and possible disk-related Extract failures, dedicate a disk to this directory. You can assign a name to this directory with the CACHEDIRECTORY option of the CACHEMGR parameter.

It is typically more efficient for the operating system to swap to disk than it is for Extract to write temporary files. The default CACHESIZE setting assumes this. Thus, there should be sufficient disk space to account for this, because only after the value for CACHESIZE is exceeded will Extract write transaction cached data to temporary files in the file system name space. If multiple Extract processes are running on a system, the disk requirements can multiply. Oracle GoldenGate writes to disk when there is not enough memory to store an open transaction. Once the transaction has been committed or rolled back, committed data is written to trail files and the data are released from memory and Oracle GoldenGate no longer keeps track of that transaction. There are no minimum disk requirements because when transactions are committed after every single operation these transactions are never written to disk.

Important:

Oracle recommends that you do not change the CACHESIZE because performance can be adversely effected depending on your environment.

1.2.2.3 Other Disk Space Considerations

In addition to the disk space required for the files and binaries that are installed by Oracle GoldenGate, allow an additional 1 GB of disk space on any system that hosts the Oracle GoldenGate trail (or trails). A trail is a set of self-aging files that contain the working data at rest and during processing. You may need more or less than this amount, because the space that is consumed by the trails depends on the volume of data that will be processed. See the guidelines for sizing trails in Administering Oracle GoldenGate.

Disk space is also required for the Oracle GoldenGate Bounded Recovery feature. Bounded Recovery is a component of the general Extract checkpointing facility. It caches long-running open transactions to disk at specific intervals to enable fast recovery upon a restart of Extract. At each bounded recovery interval (controlled by the BRINTERVAL option of the BR parameter) the disk required is as follows: for each transaction with cached data, the disk space required is usually 64k plus the size of the cached data rounded up to 64k. Not every long-running transaction is persisted to disk. For complete information about Bounded Recovery, see the BR parameter in Reference for Oracle GoldenGate.

1.2.3 Network

The following network resources must be available to support Oracle GoldenGate.

• For optimal performance and reliability, especially in maintaining low latency on the target, use the fastest network possible and install redundancies at all points of failure.

• Configure the system to use both TCP/IP and UDP services, including DNS. Oracle GoldenGate supports IPv4 and IPv6 and can operate in a system that supports one or both of these protocols.

• Configure the network with the host names or IP addresses of all systems that will be hosting Oracle GoldenGate processes and to which Oracle GoldenGate will be connecting. Host names are easier to use.

• Oracle GoldenGate requires some unreserved and unrestricted TCP/IP ports, the number of which depends on the number and types of processes in your configuration. See Administering Oracle GoldenGate for details on how to configure the Manager process to handle the required ports.

• Keep a record of the ports that you assigned to Oracle GoldenGate processes. You specify them with parameters when configuring deployments for the Microservices Architecture and for the Manager and pumps with the Classic Architecture.

• Configure your firewalls to accept connections through the Oracle GoldenGate ports.

1.2.4 Operating System Privileges

The following are the privileges in the operating system that are required to install Oracle GoldenGate and to run the processes.

• The person who installs Oracle GoldenGate must be granted read and write privileges on the Oracle GoldenGate software home directory.

• To install on Windows, the person who installs Oracle GoldenGate must log in as an Administrator.

• The Oracle GoldenGate Extract and Replicat processes, and configuring deployments using the oggca.sh script must operate as an operating system user that has read, write, and delete privileges files and subdirectories in the Oracle GoldenGate directory. In addition, the oggca.sh process requires privileges to control the other Oracle GoldenGate processes.

• In classic capture mode, the Extract process reads the redo logs directly and must operate as an operating system user that has read access to the log files, both online and archived. On UNIX systems, that user must be a member of the group that owns the Oracle instance.

• Oracle recommends that you dedicate the Extract and Replicat operating system users to Oracle GoldenGate. Sensitive information might be available to anyone who runs an Oracle GoldenGate process, depending on how database authentication is configured.

1.2.5 Other Operating System Requirements

The following additional features of the operating system must be available to support Oracle GoldenGate.

• To use Oracle GoldenGate user exits, install the C/C++ Compiler, which creates the programs in the required shared object or DLL.

• Gzip to decompress the Oracle GoldenGate installation files. Otherwise, you must unzip the installation on a PC by using a Windows-based product, and then FTP it to the AIX, DB2 for i, or DB2 z/OS platforms.

• For best results on DB2 platforms, apply high impact (HIPER) maintenance on a regular basis staying within one year of the current maintenance release. The HIPER process identifies defects that could affect data availability or integrity. IBM provides Program Temporary Fixes (PTF) to correct defects found in DB2 for i and DB2 z/OS.

• Before installing Oracle GoldenGate on a Windows system, install the Microsoft Visual C ++ 2010 SP1 Redistributable Package and the Microsoft Visual C++ 2013 Redistributable Package (vcredist_x64.exe). These packages install runtime components of Visual C++ Libraries that are required for  Oracle GoldenGate processes. To download the Visual C++ 2010 SP1 package, go to https://www.microsoft.com/en-us/download/details.aspx?id=13523. To download the Visual C++ 2013 package, go to https://www.microsoft.com/en-us/download/details.aspx?id=40784.

1.2.6 Additional Considerations

Oracle GoldenGate fully supports virtual machine environments created with any virtualization software on any platform unless otherwise noted. When installing Oracle GoldenGate into a virtual machine environment, select a build that matches the database and the operating system of the virtual machine, not the host system.

Note:

Oracle has not certified any of its products on VMware virtualized environments. Oracle Support assists you if you are running Oracle products on VMware for issues that either are known to occur on the native OS or can be demonstrated not to be as a result of running on VMware.

1.2.7 Installing the Oracle GoldenGate Files

To install the Oracle GoldenGate files:

1. Extract the Oracle GoldenGate installation file to the system and directory where you want to install Oracle GoldenGate.
2. Run the command shell.
3. Change directories to the new Oracle GoldenGate directory.
4. From the Oracle GoldenGate directory, run the GGSCI program.

   GGSCI
   

5. In GGSCI, issue the following command to create the Oracle GoldenGate working directories.

   CREATE SUBDIRS
   

6. Issue the following command to exit GGSCI.

   EXIT
   

1.2.8 Windows Console Character Sets

The operating system and the command console must have the same character sets. Mismatches occur on Microsoft Windows systems, where the operating system is set to one character set, but the DOS command prompt uses a different, older DOS character set. Oracle GoldenGate uses the character set of the operating system to send information to GGSCI command output; therefore a non-matching console character set causes characters not to display correctly. You can set the character set of the console before opening a GGSCI session by using the following DOS command:

chcp codepagenumber

For example, chcp 437.

For a code page overview, see https://msdn.microsoft.com/en-us/library/windows/desktop/dd317752(v=vs.85).aspx and the list of code page identifiers https://msdn.microsoft.com/en-us/library/windows/desktop/dd317756(v=vs.85).aspx.

1.3 Understanding and Obtaining the Oracle GoldenGate Distribution

For complete information about how to obtain Oracle Fusion Middleware software, see Obtaining Product Distributions in Planning an Installation of Oracle Fusion Middleware.

To obtain Oracle GoldenGate follow these steps:

1. Go to the Oracle GoldenGate download page in the Oracle Technology Network: http://www.oracle.com/technetwork/middleware/goldengate/downloads/index.html
2. Find the Oracle GoldenGate release you want and download the ZIP file onto your system.