6.5 Server Parameters

This section provides a consolidated overview of key server configuration parameters used in Oracle GoldenGate Veridata. These parameters, typically defined in the veridata.cfg configuration file, impacts the server behavior, including performance tuning, memory management, sorting, email notifications, reporting, repair operations, and handling of out-of-sync (OOS) records. Understanding and tuning these parameters appropriately improves system performance, optimizes comparison jobs, and ensures reliable operation of Veridata in diverse deployment environments.

Server configuration in Oracle GoldenGate Veridata can be modified through parameters defined in the veridata.cfg file, located at DOMAIN_HOME/config/veridata/veridata.cfg.

Refer How to Set a Parameter for details on how to set a parameter.

Note:

Modification in these parameters will require server restart.

• Overview of the Server Memory
  
• Estimating Memory Usage
  
• How to Set a Parameter
  
• Parameter Descriptions
  

6.5.1 Overview of the Server Memory

Oracle GoldenGate Veridata Server uses virtual memory in the following ways:

• Server memory for basic operation: This is the size of the virtual memory that the Veridata server and web components need to operate. It stores object pools, database access libraries, and other information. This is typically about 200 MB.
• Sort memory: This is the memory that is used when server-side sorting is used. The virtual memory for sorting is allocated for the entire comparison, not per thread. The rows are read from the agent and submitted to be sorted. The sorting occurs in a thread that is separate from the thread that reads from the agent, and the sort may use more threads to work in parallel. After all the rows from the agent are submitted to the sort process, the server process retrieves the sorted rows from the sort for comparison.
• Row hash queue memory: This is the memory that buffers data between the agent processes, the sort process, and the server process. A comparison that uses database sorting requires a single queue each for the source and target. Each queue has a capacity of 20 MB. The memory usage by the queues is affected by the relative speed of the comparison and by the data coming from the agent. The relative speed between the two agents also affects the memory usage. A larger differential in speed increases the amount of memory that is used, because the queue needs to buffer the data.
• MOOS queue memory: This is the memory that holds potentially out-of-sync records between the initial comparison and confirmation steps of a comparison. The size of the MOOS queue is limited to 50K of records. Memory usage is also dependent on the width of each record.
• IPC buffer memory: This is the memory that is used to exchange messages between the server and the agent.
• Scratch runtime transient memory: This is virtual memory space.

The memory that can be used by the sort process cannot be greater than the minimum of:

• System physical memory
• Available memory in swap
• Java boot option -Xmx maximum memory setting

6.5.2 Estimating Memory Usage

The maximum amount of memory available to Oracle GoldenGate Veridata is specified by the Java boot option -Xmx. When the server-side sorting is used, a large portion of this memory is reserved for sorting during comparisons. This reserved amount is controlled by the server.max_sort_memory configuration parameter.

When a comparison is run, two buffers are allocated from the reserved sort memory. Each of these is equal to the size specified as Maximum Memory Usage (MB). Refer server.max_sort_memory.

To Estimate the Amount of Memory Used per Row

For more information about the estimating the amount of memory used per row, see Disk and Memory Requirements for the Server Component.

6.5.3 How to Set a Parameter

To set a parameter, edit its entry in the veridata.cfg file. This file is stored in the DOMAIN_HOME/config/veridata directory within the Oracle GoldenGate Veridata Server installation directory.

Open a Oracle service request before changing these parameters.

6.5.4 Parameter Descriptions

Parameter Name	Syntax / Example	Possible Values	Default Value	Description
database.hash	database.hash = false	true/false	false	Defines whether data hashing is done in the database. Supported only for Oracle.
max_lob_key_len	max_lob_key_len = 1	1 to 8000 (bytes)	0 (A value of 0 disables the feature)	Sets max length of LOB data types used as keys (in bytes). Supported for Postgres' citext.
server.convert_empty_to_null	server.convert_empty_to_null = true	true, false	true	If true, treats empty string and NULL as in-sync.
server.max_concurrent_comparison_threads	server.max_concurrent_comparison_threads = 100	numeric value 1-100	4	This parameter sets the maximum number of concurrent comparisons that can be executed. You can lower this number to reduce the impact of the server on your system. When this limit is reached, no new comparisons, starts until an active comparison completes.
server.memory_mapped_sort_directory	server.memory_mapped_sort_directory = /u01/tmp2	Directory path	-	This parameter specifies the directory path where .map files are generated. By default, it uses temp directory of the operating system. If your operating system temp directory is less than 50GB, then you should consider specifying a larger directory.
server.meta_session_handle_timeout	server.meta_session_handle_timeout = 600	Numeric (seconds)	900	Timeout (in seconds) for meta-session handle.
server.veridata_data	server.veridata_data = /u01/veridata/reports	Directory path	veridata/reports	Output directory for Veridata reports.
socket.timeout.mins	socket.timeout.mins = 0	Numeric (minutes)	0	Timeout for inactive sockets (in minutes).
server.useSsl	server.useSsl = true	true, false	false	This parameter specifies whether SSL is enabled for communication from Veridata Server to Veridata Agents.
truncate_spaces_len	truncate_spaces_len = 0	0, 1	1	Use the truncate_spaces_len parameter to control how trailing spaces in a String or Binary column are truncated. Space (U+0020) and Ideographic Space (U+3000) are the truncate targets. You can disable the truncate feature with the Truncate Trailing Spaces When Comparing Values parameter of the Connection Settings tab in the Oracle GoldenGate Veridata UI of the connection configuration. This parameter also truncates the column padding character if the padding character is one of the target spaces. If the value equals 0, then all spaces are trimmed. For example, data = "". If the value equals 1, then at least one space gets retained. For example data = " ".
jvm.memory.xms	jvm.memory.xms = <min_heap_size>	Memory value (e.g., 8g)	-	Minimum JVM heap size. This can be modified by editing <VERIDATA_HOME>/config/oggvdt_cainput.properties. See section "What should be the optimum memory for server?"
jvm.memory.xmx	jvm.memory.xmx = <max_heap_size>	Memory value (e.g., 28g)	-	Maximum JVM heap size. This can be modified by editing <VERIDATA_HOME>/config/oggvdt_cainput.properties. See section "What should be the optimum memory for server?"
server.max_sort_memory	server.max_sort_memory = 1000M	Memory value (e.g., 1000M)	The system calculates the default size based on the available virtual memory.	Sets total sort memory for all comparisons. This parameter sets the maximum amount of sort virtual memory that is available to all running comparisons that use server-side sorting. The value of this parameter varies depending on the value of server.mapped_sort_buffers. server.max_sort_memory {default | number{M | m}} default is illustrated in the follows: When server.mapped_sort_buffers is set to true, the default value is 2 GB. The maximum number supposed to enter is the maximum size of the memory mapped file. When server.mapped_sort_buffers is set to false, the default value is the JVM available heap size minus 200 MB, which is allocated for basic tasks. The maximum number supposed to enter is the value of java -Xmx.
server.mapped_sort_buffers	server.mapped_sort_buffers = true	true, false	true, false	Indicates whether sort buffers are allocated as a memory mapped file or allocated on the JVM heap.
server.number_sort_threads	server.number_sort_threads = <number>	Max of 4 or 1/4 of CPU cores	4	This parameter specifies the number of threads used to sort input buffers from the Veridata Agent.
mail.enabled	mail.enabled = false	true, false	false	Enables/disables email notifications.
mail.alert.only	mail.alert.only = true	true, false	true	If true, send only alert emails (not completion).
mail.smtp.server	mail.smtp.server = smtp.host.com	SMTP server hostname	-	SMTP server hostname.
mail.smtp.port	mail.smtp.port = 25	Numeric port number	-	SMTP server port.
mail.smtp.connection.ssl.tls	mail.smtp.connection.ssl.tls = true	true, false	false	Enables SSL/TLS for mail server connection.
mail.from	mail.from = [e-mail]	Valid email address	-	Sender email address.
mail.to	mail.to = [e-mail],[e-mail]	Comma-separated email addresses	-	Recipient email addresses (comma-separated).
server.encryption	server.encryption = false	true, false	false	Enables encryption for comparison and repair reports.
server.encryption.bits	server.encryption.bits = 128	128, 192, 256	128	Encryption strength in bits.
repair.oracle.tag.enable	repair.oracle.tag.enable = false	true, false	true	Enables tagging of repair sessions in Oracle redo logs.
repair.oracle.tag	repair.oracle.tag = 00	Value can be up to 2000 hexadecimal digits (0-9A-F) or the plus sign (+).	00	Hexadecimal tag used in Oracle redo logs.
coos.join.strategy	coos.join.strategy = nokey	nokey, always, never	nokey	nokey - Use COOS Join strategy only when Use all columns as Key columns (there is no primary or unique constraint on the table) is used to select key columns for the compare pair. All columns as key columns in the compare pair exception XML, UDT and Lobs. always - Use COOS Join always for COOS step. never - Don't use COOS Join for COOS Step.
skiprows.enabled	skiprows.enabled = true	true, false	true	Skips rows with invalid numbers to allow comparison to continue.