Cassandra Data Migrator parameters
Each parameter below offers a different connection. Review each option to determine what is best for your organization.
Common connection parameters for origin and target
| Property | Default | Notes |
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Hostname/IP address of the cluster.
May be a comma-separated list, and can follow the |
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Port number to use if not specified on |
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(Not set) |
Secure Connect Bundle, used to connect to an Astra DB database.
Example: |
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Username (or |
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Password (or |
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Hostname/IP address of the cluster.
May be a comma-separated list, and can follow the |
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Port number to use if not specified on |
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(Not set) |
Secure Connect Bundle, used to connect to an Astra DB database.
Default is not set.
Example if set: |
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Username (or |
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Password (or |
Origin schema parameters
| Property | Default | Notes | ||
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Required - the |
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Default is |
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Default is empty, meaning the names are determined automatically if |
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Default is
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Default is empty, meaning the names are determined automatically if |
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Default is empty.
If column names are changed between the origin and target clusters, then this mapped list provides a mechanism to associate the two.
The format is |
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For optimization reasons, Cassandra Data Migrator does not migrate TTL and writetime at the field level. Instead, Cassandra Data Migrator finds the field with the highest TTL and the field with the highest writetime within an origin table row, and uses those values on the entire target table row. |
Target schema parameter
| Property | Default | Notes |
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Equals the value of |
This parameter is commented out.
It’s the |
Auto-correction parameters
Auto-correction parameters allow Cassandra Data Migrator to correct data differences found between the origin and target clusters when you run the DiffData program.
Typically, these parameters are run-disabled for "what if" migration testing, and generate a list of data discrepancies.
The reasons for these discrepancies can then be investigated, and if necessary the parameters below can be enabled.
For information about invoking DiffData in a Cassandra Data Migrator command, see Cassandra Data Migrator steps in validation mode.
| Property | Default | Notes | ||
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When |
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When
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Commented out. By default, counter tables are not copied when missing, unless explicitly set. |
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Commented out. This CSV file is used as input, as well as output, when applicable. If the file exists, only the partition ranges in this file are migrated or validated. Similarly, if exceptions occur while migrating or validating, partition ranges with exceptions are logged to this file. |
Performance and operations parameters
Performance and operations parameters that can affect migration throughput, error handling, and similar concerns.
| Property | Default | Notes |
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In standard operation, the full token range of -2^63 to 2^63-1 is divided into a number of parts, which are parallel processed.
You should aim for each part to comprise a total of ≈1-10GB of data to migrate.
During initial testing, you may want this to be a small number, such as |
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When writing to the target cluster, this comprises the number of records that are put into an |
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Concurrent number of operations across all parallel threads from the origin cluster. This value may be adjusted up or down, depending on the amount of data and the processing capacity of the origin cluster. |
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Concurrent number of operations across all parallel threads from the target cluster. This may be adjusted up or down, depending on the amount of data and the processing capacity of the target cluster. |
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Commented out.
Read consistency from the origin cluster and from the target cluster when records are read for comparison purposes.
The consistency parameters may be one of: |
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Commented out.
Write consistency to the target cluster.
The consistency parameters may be one of: |
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Commented out. Number of rows of processing after which a progress log entry is made. |
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Commented out. This parameter affects the frequency of reads from the origin cluster and the frequency of flushes to the target cluster. |
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Commented out.
Controls how many errors a thread may encounter during |
Transformation parameters
Parameters to perform schema transformations between the origin and target clusters.
By default, these parameters are commented out.
| Property | Default | Notes | ||
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Timestamp value in milliseconds.
Partition and clustering columns cannot have null values.
If they are added as part of a schema transformation between the origin and target clusters, it is possible that the origin side is null.
In this case, the |
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Default is 0 (disabled).
Timestamp value in microseconds to use as the |
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Default is |
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Default is empty. A comma-separated list of additional codecs to enable.
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Configuration for |
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Default is |
Cassandra filter parameters
Cassandra filters are applied on the coordinator node.
Depending on the filter, the coordinator node may need to do a lot more work than is normal, notably because Cassandra Data Migrator specifies ALLOW FILTERING.
By default, these parameters are commented out.
| Property | Default | Notes |
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Default is |
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Default is |
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CQL added to the |
Java filter parameters
Java filters are applied on the client node.
Data must be pulled from the origin cluster and then filtered.
However, this option may have a lower impact on the production cluster than Cassandra filters.
Java filters put a load onto the Cassandra Data Migrator processing node.
They send more data from Cassandra.
Cassandra filters put a load on the Cassandra nodes because Cassandra Data Migrator specifies ALLOW FILTERING, which could cause the coordinator node to perform a lot more work.
By default, these parameters are commented out.
| Property | Default | Notes |
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Between 1 and 100 percent of the token in each split that is migrated. This property is used to do a wide and random sampling of the data. The percentage value is applied to each split. Invalid percentages are treated as 100. |
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The lowest (inclusive) writetime values to be migrated.
Using the |
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The highest (inclusive) writetime values to be migrated.
The |
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Filter rows based on matching a configured value.
With |
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String value to use as comparison.
The whitespace on the ends of |
Constant column feature parameters
The constant columns feature allows you to add constant columns to the target table.
If used, the spark.cdm.feature.constantColumns.names, spark.cdm.feature.constantColumns.types, and spark.cdm.feature.constantColumns.values lists must all be the same length.
By default, these parameters are commented out.
| Property | Default | Notes |
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A comma-separated list of column names, such as |
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A comma-separated list of column types. |
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A comma-separated list of hard-coded values.
Each value should be provided as you would use on the |
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Defaults to comma, but can be any regex character that works with |
Explode map feature parameters
The explode map feature allows you convert an origin table map into multiple target table records.
By default, these parameters are commented out.
| Property | Notes |
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The name of the map column, such as |
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The name of the column on the target table that holds the map key, such as |
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The name of the column on the target table that holds the map value, such as |
Guardrail feature parameter
The guardrail feature manages records that exceed guardrail checks. The guardrail job generates a report; other jobs skip records that exceed the guardrail limit.
By default, these parameters are commented out.
| Property | Default | Notes |
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The |
TLS (SSL) connection parameters
These are TLS (SSL) connection parameters, if configured, for the origin and target clusters. Note that a secure connect bundle (SCB) embeds these details.
By default, these parameters are commented out.
| Property | Default | Notes |
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If TLS is used, set to |
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Path to the Java truststore file. |
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Password needed to open the truststore. |
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Path to the Java keystore file. |
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Password needed to open the keystore. |
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If TLS is used, set to |
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Path to the Java truststore file. |
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Password needed to open the truststore. |
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Path to the Java keystore file. |
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Password needed to open the keystore. |
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