You can test connectivity between any two nodes or machines using these methods. For example: If you want to check the connection between the Veridata server and the source agent, then:

Call the Veridata server → node_1

Call the source agent → node_2

To Test Connectivity using Ping:

1. On the node_1 open a terminal and run: ping [node_2].
2. Replace [node_2] with the hostname or IP address of node_2.
3. To measure latency and to check the speed of the connection, run ping -c 4 [node_2]. The following is a sample output:

   Success Case:
   
   PING 192.168.1.2 (192.168.1.2): 56 data bytes
   
   64 bytes from 192.168.1.2: icmp_seq=0 ttl=64 time=0.123 ms
   
   --- 192.168.1.2 ping statistics ---
   
   4 packets transmitted, 4 packets received, 0.0% packet loss
   
   round-trip min/avg/max/stddev = 0.123/0.124/0.125/0.001 ms
   
   Note: If the time for round-trip is in range of milli seconds or less than then connection between source host target host is considered fast.
   
   Failure Case:
   
   PING 192.168.1.2 (192.168.1.2): 56 data bytes
   
   Request timeout for icmp_seq 0
   
   --- 192.168.1.2 ping statistics ---
   
   4 packets transmitted, 0 packets received, 100.0% packet loss

To check connectivity when Ping is not available:

1. Use Telnet to check specific ports. On the node_1, run: telnet [node_2] [port]
2. Replace [node_2] with the hostname or IP address of node_2, and [port] with the specific port number. For example, 8089.

Sample Output

Success Case:

Trying 192.168.1.2...

Connected to 192.168.1.2.

Escape character is '^]'.

Failure Case:

Trying 192.168.1.2...

telnet: Unable to connect to remote host: Connection refused

To check connectivity when Ping is not available using Netcat (NC), On the node_1, run: nc -zv [node_2] [port]

Sample Output

Success Case:

Connection to 192.168.1.2 8089 port [tcp/*] succeeded!

Failure Case:

nc: connect to 192.168.1.2 port 8089 (tcp) failed: Connection refused

How to check current memory of agent?

Locate and open agent.sh file and check the value for USER_MEM_ARGS. Here, Xmx is maximum agent memory and Xms is minimum agent memory.

What should be the optimum memory for agent?

We generally recommend that agent memory should be at least 25% of the size of the data to be compared.

How to modify the memory for agent?

Open agent.sh file and check the value for USER_MEM_ARGS. By default the value will be USER_MEM_ARGS="-Xmx1024M -Xms1024M".

To increase the memory, -Xmx value should be increased.

How to calculate disk space and memory requirements for Sort Directory?

See Disk and Memory Requirements for the Server Component.

The maximum memory available to Oracle GoldenGate Veridata is set using jvm.memory.xmx in <VERIDATA_HOME>/config/oggvdt_cainput.properties.

When server-side sorting is enabled, a significant portion of this memory is used for sorting during comparisons.

The server.max_sort_memory parameter in the veridata.cfg file determines the maximum sorting memory. To avoid issues, ensure that the jvm.memory.xmx value is higher than the sorting memory requirements.

See Server Parameters in Administering Oracle GoldenGate Veridata.

Solution - Optimizing with Key Columns

Add at least one key column or a combination of multiple key columns such that the values remain unique.

By ensuring proper key column definitions in the table, Oracle GoldenGate Veridata can perform more efficient comparisons.

To add key columns:

1. In the Oracle GoldenGate Veridata UI, go to Group and Compare Pairs.
2. Select Group and then click Compare Pair.
3. Click the Column Mapping tab.
4. Set Key Mapping Method to User Defined.
5. Set one or more columns which can be set as keys during the operation.
6. Click Save.

Working with large tables might impact Veridata performance so you can divide large source and target tables into smaller dataset.

It can be done using the following: Auto Partitions, Manual Row Partitions, or Table Partitioning.

Automatic Row Partitions

This option is available only for Oracle DB which can split the compare pair (tables) into the multiple parts based on the values you provide. Automatic Row Partitions can be configured while creating a compare pair. This speeds up the comparison as it will run on smaller dataset.

To configure Automatic Row Partitions:

1. In the Oracle GoldenGate Veridata UI, on the Compare Pair page, click Manual Mapping, and then click Automatic Row Partition .

Manual Row Partitioning

This can be useful for manually distributing the workload across multiple processes or restricting the comparison to a specific subset of data, such as the last n days. Manual Row Partitioning can be useful for manually distributing the workload across multiple processes or restricting the comparison to a specific subset of data, such as the last n days.

This option is available for both Oracle as well as non-Oracle databases. This can be achieved by applying a SQL Predicate and filtering the records.

Table Partitions

This option is available only for Oracle DB. If a table is created with partitions then all the partitions are listed on the page. You can select only required partitions during creation of Compare Pair.

To configure Table Partitions:

1. In the Oracle GoldenGate Veridata UI, go to Group and Compare Pairs.
2. Click Create, click Mapping Rules, and then select the Include Table Partitions check box.

To exclude columns:

To add key columns:

1. In the Oracle GoldenGate Veridata UI, go to Group and Compare Pairs.
2. Select Group and then click Compare Pair.
3. Click the Column Mapping tab.
4. Click Remove mapping for the columns you want to exclude.
5. Click Save.

Compare pairs can be configured to use delta processing, a performance feature that compares only the data blocks that have changed since the last run, instead of scanning the entire table.

Delta Comparison prevents comparing all the historical data again and again and compares only changed (delta) data.

To enable Delta Comparison:

1. In the Oracle GoldenGate Veridata UI, go to Group and Compare Pairs.
2. Select Group and then select a compare pair from Existing compare pair list.
3. Click Delta Processing.
4. In the Delta Processing tab, toggle Delta Processing.
5. Select Delta Columns.
6. Click Save.

SELECT owner, table_name, dependencies FROM dba_tables;

Compare Fetch Size

This configuration is useful in determining the batch size for fetching the data from database. Default value is 1000.

To speed up the compare process, the number of rows fetched from database can be increased in the connection settings by changing Compare Fetch Size. Start with 10,000 and increase up to 100,000.

To update Compare Fetch Size, from the Connections tab, open the connection that is used in the compare job and change the value of the Initial Compare Fetch Batch Size. This speeds up the fetch process during the initial comparison.

Oracle recommends you to set the value of Sort Data Using to Server, as sorting done at the Oracle GoldenGate Veridata server will be faster than sorting at the Database level.

To set this sorting method:

1. In the Oracle GoldenGate Veridata UI, click Profiles and select a profile.
2. Click the Sorting Method tab and select Sort Data Using and select a value from the drop-down list.

To update coos batch size

1. In the Oracle GoldenGate Veridata UI, click Profiles and select a profile.
2. Click the Confirm-Out-Of-Sync tab and select Confirm-Out-Of-Sync Batch Size and select a value from the drop-down list.

   Note:

   The default value is 1000. Maximum value for this field is 100,000 and minimum value is 1. Start with 10,000 and increase up to 100,000.

To set the Repair Batch Size:

1. In the Oracle GoldenGate Veridata UI, click Profiles and select a profile.
2. Click the Repair tab and select Repair Batch Size.

The veridata.cfg file is located here: <VERIDATA_HOME>/config/veridata folder. It stores many configurations that are needed to run and customise Veridata operations.

• Coos join:

  This is enabled by default for table with no unique or primary key and the behaviour can be overridden from the veridata.cfg file in the <VERIDATA_HOME>/config/veridata folder.

  With this configuration, the database queries will use join and will be a lot faster compared to queries without join.

  You need to add/edit the following properties:

  • coos.join.strategy = Values nokey, always, and never
  • nokey - This is the default value of the field and it is useful on the tables that do not have primary key/indexes defined.
  • always – Always use COOS join.
  • never - Don't use COOS Join.
• server.concurrent.writers: The number of writer threads per sort directory.
• server.concurrent.readers: The number of reader threads for entire server.
• server.number_sort_threads: The number of threads used to sort input buffers from the agent. Should not be larger than number of available processes.

What is a sort directory?

In the sorting phase, chunks of data small enough to fit in main memory are read, sorted, and written out to a temporary file in a directory.

How to find a sort directory?

This can be found from profile setting page under Sorting Method.

1. Go to Profiles, Select Profile, and click Sorting method
2. Select Temporary Storage Directory for Source Data and click Temporary Storage Directory for Target Data.

What is Agent Properties file location?

This can be found in <agent_home> path with name agent.properties.

Where is Veridata server config file present?

<VERIDATA_HOME>/config/veridata/veridata.cfg

Where is oggvdt_cainput.properties file present?

<VERIDATA_HOME>/config/oggvdt_cainput.properties

Where to find the Reports?

Reports are present in path: <VERIDATA_HOME>/veridata/reports

Can we have multiple agents for 1 DB?

Yes. But we recommend 1 agent for 1 DB.

How many Compare pairs I can create in a group?

No restriction on this. Any number is fine.

How many Compare pairs I can run in parallel?

100 is the max default number. But it can be updated from veridata.cfg file by changing the value of max_concurrent_jobs.