2.132 RMTHOST

Valid For

Extract

Description

Use the RMTHOST parameter to:

  • Identify a remote system to which the local Extract process connects

  • Specify the TCP/IP port number on that system where the Manager process is running

  • Control various attributes of the TCP/IP connections

This parameter controls compression, data encryption, buffer attributes, TCP/IP streaming, connection timeout threshold, and the wait period for a connection request. It also can be used to set Collector parameters.

To identify multiple remote systems in a parameter file, use one RMTHOST statement for each one, followed by the associated trails and table maps, for example:

EXTRACT sales
USERIDALIAS tiger1
RMTHOST ny, MGRPORT 7888, ENCRYPT AES192 KEYNAME mykey
RMTTRAIL /ggs/dirdat/aa
TABLE ora.orders;
RMTHOST la, MGRPORT 7888, ENCRYPT AES192 KEYNAME mykey2
RMTTRAIL /ggs/dirdat/bb
TABLE ora.orders;

Do not use RMTHOST for an Extract created in PASSIVE mode. .

Oracle GoldenGate supports IPv4 and IPv6 protocols. See USEIPV4 for more information about the selection of internet protocol.

The RMTHOST and RMTHOSTOPTIONS parameters can be specified together; the RMTHOST parameter is not required for RMTHOSTOPTIONS if the dynamic IP assignment is properly configured. When RMTHOSTOPTIONS is used, the MGRPORT option is ignored.

Default

None

Syntax

RMTHOST
{ host name | IP address}
[, COMPRESS]
[, COMPRESSTHRESHOLD]
[, ENCRYPT {BLOWFISH KEYNAME key_name | algorithm [KEYNAME key_name]} ] 
{, MGRPORT port | PORT port}
[, PARAMS collector_parameters]
[, SOCKSPROXY {host_name | IP address} [:port] [PROXYCSALIAS credential_
store_alias [PROXYCSDOMAIN credential_store_domain]] 
[, STREAMING | NOSTREAMING]
[, TCPBUFSIZE bytes]
[, TCPFLUSHBYTES bytes]
[, TIMEOUT seconds]
[, DGST SHA1|SHA2]
{host_name | IP_address}

The DNS host name or IP address of the target system. You can use either one to define the host. If using an IP address, use either an IPv6 or IPv4-mapped address, depending on the stack of the destination system.

COMPRESS

This option is valid for online or batch Extract processes and any Oracle GoldenGate initial-load method that uses trails. Compresses outgoing blocks of records to reduce bandwidth requirements. Oracle GoldenGate decompresses the data before writing it to the trail. COMPRESS typically results in compression ratios of at least 4:1 and sometimes better. However, compressing data can consume CPU resources.

COMPRESSTHRESHOLD

This option is valid for online or batch Extract processes and any Oracle GoldenGate initial-load method that uses trails. Sets the minimum block size for which compression is to occur. Valid values are from 0 and through 28000. The default is 1,000 bytes.

ENCRYPT algorithm [KEYNAME key_name]

This option is valid for online or batch Extract processes and all Oracle GoldenGate initial-load methods. Encrypts the data stream sent over TCP/IP to the target system. This option supports the following encryption options:

  • Master key and wallet method: Generate a session key based on the active master key and algorithm specified. Not valid for BLOWFISH algorithm. Not valid for DB2 on z/OS, and DB2 for i.

  • ENCKEYS method: Generate an AES encryption key, store it under a given name in an ENCKEYS file, and configure Oracle GoldenGate to use that key to encrypt the data.

algorithm

Specifies the encryption algorithm to use:

  • AES128 uses the AES-128 cipher, which has a key size of 128 bits. AES128 is the default if no algorithm is specified.

  • AES192 uses the AES-192 cipher, which has a key size of 192 bits.

  • AES256 uses the AES-256 cipher, which has a key size of 256 bits.

  • BLOWFISH uses Blowfish encryption with a 64-bit block size and a variable-length key size from 32 bits to 128 bits. Use BLOWFISH for backward compatibility with earlier Oracle GoldenGate versions and for Oracle GoldenGate installations for DB2 z/OS and DB2 for i. On those platforms, BLOWFISH is the only supported encryption method. Use AES where supported, because it is more secure than BLOWFISH for those platforms.

KEYNAME key_name

Specifies that the ENCKEYS method of encryption will be used. Not valid for the master key and wallet method. For key_name, specify the logical name of the user-defined encryption key. Oracle GoldenGate uses the key name to look up the actual key in the ENCKEYS lookup file. To use the ENCKEYS method, you must:

  • Generate the encryption key.

  • Store it in an ENCKEYS lookup file.

  • Copy ENCKEYS to every system where encryption or decryption (or both) are performed.

To use AES encryption for any database other than Oracle on a 32-bit platform, the path of the lib sub-directory of the Oracle GoldenGate installation directory must be specified as an environment variable before starting any processes. This is not required on 64-bit platforms. Set the path as follows:

  • For Linux: Specify the path as an entry to the LD_LIBRARY_PATH. For example:

    setenv LD_LIBRARY_PATH ./lib:$LD_LIBRARY_PATH
    
  • For Solaris: Specify the path as an entry to the SHLIB_PATH variable.

  • For IBMi and AIX: Specify the path as an entry to the LIBPATH variable.

  • For Windows: Add the path to the PATH variable.

You can use the SETENV parameter to set the library as a session variable for the process.

For more information about using encryption, see Overview of Security Options in Securing the Oracle GoldenGate Environment.

MGRPORT port | PORT port

Either MGRPORT or PORT is required. MGRPORT is the port on the remote system where Manager runs. PORT is the port number of a static Collector process. Either a Manager port (if using a dynamic Collector) or a static Collector port must be specified. See "Collector Parameters" for more information about a static Collector. The minimum is 1025 and the maximum is 65535.

SOCKSPROXY {host_name | IP address} [:port] [PROXYCSALIAS credential_store_alias [PROXYCSDOMAIN credential_store_domain]]

Use the SOCKSPROXY parameter to replicate information using a SOCKS5 proxy server creating a tunnel for TCP communication between a source Extract and a target process. The connection is initiated in the source side. You must specify the proxy address. Optionally you can specify the port or the default for SOCKS protocol will be used. If a credential store alias is specified, Oracle GoldenGate will use that information to authenticate with the proxy server. This is an option for RMTHOST parameter.

If there is no credential store information, no authentication with the proxy is performed.

host_name | IP_address

Use for an alias Extract. Specifies the DNS host name or IP address of the proxy server. You can use either one to define the host though you must use the IP address if your DNS server is unreachable. If you are using an IP address, use either an IPv6 or IPv4 mapped address, depending on the stack of the destination system.

port

(Optional) Specifies the port on the remote system where the proxy server accepts connections. The default value for port is 1080.

PROXYCSALIAS credential_store_alias

Specifies the credential store alias that resolves to the username and password used to authenticate with the proxy server.

PROXYCSDOMAIN credential_store_domain

(Optional) Specifies the credential store domain used together with the alias.

STREAMING | NOSTREAMING

This option is valid for online or batch Extract processes and any Oracle GoldenGate initial-load method that uses trails. Controls TCP/IP streaming.

STREAMING

Enables the asynchronous internet streaming protocol and is the default. In STREAMING mode, the receiver (Collector) does not send an acknowledgement to the sender (primary Extract or data pump) for any data packet unless the packet contains a flag requesting a response, typically when the sender must checkpoint or determine a write position. Because this method omits acknowledgements, the sender or receiver process terminates if there is a network disruption; therefore, when using STREAMING, use the AUTORESTART parameter in the Manager parameter file to restart Extract and Collector if they terminate.

NOSTREAMING

Enables the synchronous internet protocol. In NOSTREAMING mode, the sender sends a packet and then waits for the receiver to acknowledge it, before sending the next packet. This method is more reliable, because it enables the sender or receiver process to recover if there is a network disruption.

Extract falls back to the synchronous protocol automatically if the host system of the receiver process is not configured to use streaming.

Keep the STREAMING default unless you are requested to disable it, because streaming reduces transmission latency, especially in networks where latency is a problem already. Streaming is not supported for initial-load tasks where Extract communicates directly with Replicat.

TCPBUFSIZE bytes

This option is valid for online or batch Extract processes and any Oracle GoldenGate initial-load method that uses trails. Controls the size of the TCP socket buffer, in bytes, that Extract will try to maintain.

By increasing the size of the buffer, you can send larger packets to the target system.The actual size of the buffer depends on the TCP stack implementation and the network. The default is 30,000 bytes, but modern network configurations usually support higher values. Valid values are from 1000 to 200000000 (two hundred million) bytes. Work with your network administrator to determine an optimal value. See also Administering Oracle GoldenGate for more information about tuning the buffer size and other suggestions for improving the transfer of data across the network.

Testing has shown that using TCPBUFSIZE for initial loads produces three times faster throughput than loads performed without it. Do not use this parameter if the target system is NonStop.

TCPFLUSHBYTES bytes

This option is valid for online or batch Extract processes and any Oracle GoldenGate initial-load method that uses trails. Controls the size of the buffer, in bytes, that collects data that is ready to be sent across the network.

When either this value or the value of the FLUSHSECS parameter is reached, the data is flushed to the target. The default is 30,000 bytes. Valid values are from 1000 to 200000000 (two hundred million) bytes, but should be at least the value of TCPBUFSIZE.

Do not use this parameter for an initial load Extract. It is valid only for an online Extract group. Do not use this parameter if the target system is NonStop.

TIMEOUT seconds

This option is valid for online or batch Extract processes and any Oracle GoldenGate initial-load method that uses trails. Specifies how long Collector waits to get a connection from Extract, and how long Collector waits for a heartbeat signal from Extract before terminating a connection. Valid values are 1 second to 1800 seconds (30 minutes). The default value is 300 seconds (5 minutes). Setting the timeout to a very low value is not recommended in a production setting. You might need to increase the TIMEOUT value if you see a warning in the error log that there was a TCP/IP error 10054 (existing connection forcibly closed by remote host). This error typically occurs when the Collector terminates itself after the TIMEOUT value is exceeded. This parameter does not affect a static Collector.

DGST SHA1|SHA2
This is a new Extract option to specify the AES encryption method. This option is only valid when the RMTHOST parameter is used with PORT and ENCRYPT AES options using Oracle wallet. Valid value is either SHA1 or SHA2. SHA1 is default and works with the previous release of server collector. SHA2 only works with Server Collector 12.3. Both Extract and Server Collector must specify the same encryption method, otherwise the connection fails. Here’s an example of using this option:

$ server -p 9050 -encrypt AES128 -dgst SHA2

Examples

Example 1   
RMTHOST 20.20.20.17, MGRPORT 7809, ENCRYPT AES192, KEYNAME newyork
Example 2   
RMTHOST 20.20.20.17, MGRPORT 7809, ENCRYPT AES192
Example 3   
RMTHOST newyork, MGRPORT 7809, COMPRESS, COMPRESSTHRESHOLD 750, NOSTREAMING
Example 4   
RMTHOST newyork, MGRPORT 7809, TCPBUFSIZE 100000, TCPFLUSHBYTES 300000
Example 5   
RMTHOST newyork, MGRPORT 18819, CPU 1, PRI 140, HOMETERM $ZTN0.#PTJ52A1, PROCESSNAME $xyz1
Example 6   
RMTHOST lc01abc, MGRPORT 7809, SOCKSPROXY 192.111.82.180:3128 PROXYCSALIAS 
proxyAlias PROXYCSDOMAIN support