Template for exporting a Cassandra table to Bigquery
cassandratobq.input.host: Cassandra Host IPcassandratobq.bigquery.location: Dataset and Table namecassandratobq.temp.gcs.location: Temp Cloud Storage location for staging
cassandratobq.input.keyspace: Input keyspace name for cassandracassandratobq.input.table: Input table name of cassandracassandratobq.input.query: Customised query for selective migrationcassandratobq.input.catalog.name: Connection name, defaults to cassconcassandratobq.output.mode: Output mode of Cassandra to Bq, defaults to Append mode
$ python main.py --template CASSANDRATOBQ --help
usage: main.py --template CASSANDRATOBQ [-h] \
--cassandratobq.input.host CASSANDRA.DATABASE.HOST.IP \
--cassandratobq.bigquery.location BIGQUERY.DATASET.TABLE.LOCATION \
--cassandratobq.temp.gcs.location TEMPORARY.GCS.STAGING.LOCATION \
optional arguments:
-h, --help show this help message and exit
--cassandratobq.input.keyspace CASSANDRA.INPUT.KEYSPACE \
--cassandratobq.input.table CASSANDRA.INPUT.TABLE \
--cassandratobq.output.mode {overwrite,append,ignore,errorifexists} \
--cassandratobq.input.query CASSANDRA.INPUT.QUERY \
--cassandratobq.input.catalog.name CASSANDRA.INPUT.CATALOG.NAME
Note: Make sure that either cassandratobq.input.query or both cassandratobq.input.keyspace and cassandratobq.input.table is provided. Setting or not setting all three properties at the same time will throw an error.
This template requires the Spark Cassandra connector to be available in the Dataproc cluster. This can be downloaded using the following link. Another jar of POSIX handler is also required which can be downloaded from this link
Use the following command to download the jar-:
wget https://repo1.maven.org/maven2/com/datastax/spark/spark-cassandra-connector-assembly_2.12/3.2.0/spark-cassandra-connector-assembly_2.12-3.2.0.jar
wget https://repo1.maven.org/maven2/com/github/jnr/jnr-posix/3.1.8/jnr-posix-3.1.8.jar
Jar files named spark-cassandra-connector-assembly_2.12-3.2.0.jar and jnr-posix-3.1.8.jar would be downloaded, this can be passed to provide spark drivers and workers with cassandra connector class and its dependencies.
export GCP_PROJECT=<project_id>
export JARS="gs://path/to/jar/spark-cassandra-connector_2.12-3.2.0.jar,gs://path/to/jnr-posix-3.1.8.jar" # Pass the downloaded jar path
export GCS_STAGING_LOCATION=<gcs-staging-bucket-folder>
export REGION=<region>
./bin/start.sh \
-- --template=CASSANDRATOBQ \
--cassandratobq.input.keyspace=<keyspace name> \
--cassandratobq.input.table=<cassandra table name> \
--cassandratobq.input.host=<cassandra host IP> \
--cassandratobq.bigquery.location=<dataset.tablename> \
--cassandratobq.temp.gcs.location=<staging bucket name> \
--cassandratobq.output.mode=<overwrite|append|ignore|errorifexists>
After downloading the jar, a sample submission -:
export GCP_PROJECT=my-project
export REGION=us-central1
export GCS_STAGING_LOCATION=gs://staging_bucket
export SUBNET=projects/my-project/regions/us-central1/subnetworks/default
export JARS="gs://jar-bucket/spark-cassandra-connector-assembly_2.12-3.2.0.jar,gs://jar-bucket/jnr-posix-3.1.8.jar"
./bin/start.sh \
-- --template=CASSANDRATOBQ \
--cassandratobq.input.host=10.1X8.X.XX \
--cassandratobq.bigquery.location=demo.cassandramig \
--cassandratobq.temp.gcs.location=bucketname \
--cassandratobq.input.query="select emp_id from casscon.tk1.emp"
Template for exporting a Cassandra table to Cloud Storage
cassandratogcs.input.keyspace: Input keyspace name for cassandra (not required when query is present)cassandratogcs.input.table: Input table name of cassandra (not required when query is present)cassandratogcs.input.host: Cassandra Host IPcassandratogcs.output.format: Output File Formatcassandratogcs.output.path: Cloud Storage Bucket Pathcassandratogcs.output.savemode: Output mode of Cassandra to Cloud Storage
cassandratobq.input.query: Customised query for selective migrationcassandratogcs.input.catalog.name: Connection name, defaults to cassconcassandratogcs.output.chartoescapequoteescaping: Sets a single character used for escaping the escape for the quote character. The default value is escape character when escape and quote characters are different, \0 otherwisecassandratogcs.output.compression: Compression codec to use when saving to file. This can be one of the known case-insensitive short names (none, bzip2, gzip, lz4, snappy and deflate)cassandratogcs.output.dateformat: Sets the string that indicates a date format. This applies to date typecassandratogcs.output.emptyvalue: Sets the string representation of an empty valuecassandratogcs.output.encoding: Specifies encoding (charset) of saved CSV filescassandratogcs.output.escape: Sets a single character used for escaping quotes inside an already quoted valuecassandratogcs.output.escapequotes: A flag indicating whether values containing quotes should always be enclosed in quotes. Default is to escape all values containing a quote charactercassandratogcs.output.header: Writes the names of columns as the first line. Defaults to Truecassandratogcs.output.ignoreleadingwhitespace: A flag indicating whether or not leading whitespaces from values being read/written should be skippedcassandratogcs.output.ignoretrailingwhitespace: A flag indicating whether or not trailing whitespaces from values being read/written should be skippedcassandratogcs.output.linesep: Defines the line separator that should be used for parsing. Defaults to \r, \r\n and \n for reading and \n for writingcassandratogcs.output.nullvalue: Sets the string representation of a null valuecassandratogcs.output.quote: Sets a single character used for escaping quoted values where the separator can be part of the value. For writing, if an empty string is set, it uses u0000 (null character)cassandratogcs.output.quoteall: A flag indicating whether all values should always be enclosed in quotes. Default is to only escape values containing a quote charactercassandratogcs.output.sep: Sets a separator for each field and value. This separator can be one or more characterscassandratogcs.output.timestampformat: Sets the string that indicates a timestamp with timezone formatcassandratogcs.output.timestampntzformat: Sets the string that indicates a timestamp without timezone format
$ python main.py --template CASSANDRATOGCS --help
usage: main.py [-h]
--cassandratogcs.input.host CASSANDRATOGCS.INPUT.HOST
--cassandratogcs.output.format {avro,parquet,csv,json}
--cassandratogcs.output.path CASSANDRATOGCS.OUTPUT.PATH
[--cassandratogcs.output.savemode {overwrite,append,ignore,errorifexists}]
[--cassandratogcs.input.catalog.name CASSANDRATOGCS.INPUT.CATALOG.NAME]
[--cassandratogcs.input.query CASSANDRATOGCS.INPUT.QUERY]
[--cassandratogcs.input.keyspace CASSANDRATOGCS.INPUT.KEYSPACE]
[--cassandratogcs.input.table CASSANDRATOGCS.INPUT.TABLE]
[--cassandratogcs.output.chartoescapequoteescaping CASSANDRATOGCS.OUTPUT.CHARTOESCAPEQUOTEESCAPING]
[--cassandratogcs.output.compression CASSANDRATOGCS.OUTPUT.COMPRESSION]
[--cassandratogcs.output.dateformat CASSANDRATOGCS.OUTPUT.DATEFORMAT]
[--cassandratogcs.output.emptyvalue CASSANDRATOGCS.OUTPUT.EMPTYVALUE]
[--cassandratogcs.output.encoding CASSANDRATOGCS.OUTPUT.ENCODING]
[--cassandratogcs.output.escape CASSANDRATOGCS.OUTPUT.ESCAPE]
[--cassandratogcs.output.escapequotes CASSANDRATOGCS.OUTPUT.ESCAPEQUOTES]
[--cassandratogcs.output.header CASSANDRATOGCS.OUTPUT.HEADER]
[--cassandratogcs.output.ignoreleadingwhitespace CASSANDRATOGCS.OUTPUT.IGNORELEADINGWHITESPACE]
[--cassandratogcs.output.ignoretrailingwhitespace CASSANDRATOGCS.OUTPUT.IGNORETRAILINGWHITESPACE]
[--cassandratogcs.output.linesep CASSANDRATOGCS.OUTPUT.LINESEP]
[--cassandratogcs.output.nullvalue CASSANDRATOGCS.OUTPUT.NULLVALUE]
[--cassandratogcs.output.quote CASSANDRATOGCS.OUTPUT.QUOTE]
[--cassandratogcs.output.quoteall CASSANDRATOGCS.OUTPUT.QUOTEALL]
[--cassandratogcs.output.sep CASSANDRATOGCS.OUTPUT.SEP]
[--cassandratogcs.output.timestampformat CASSANDRATOGCS.OUTPUT.TIMESTAMPFORMAT]
[--cassandratogcs.output.timestampntzformat CASSANDRATOGCS.OUTPUT.TIMESTAMPNTZFORMAT]
options:
-h, --help show this help message and exit
--cassandratogcs.input.host CASSANDRATOGCS.INPUT.HOST
CASSANDRA Cloud Storage Input Host IP
--cassandratogcs.output.format {avro,parquet,csv,json}
Output file format (one of: avro,parquet,csv,json)
--cassandratogcs.output.path CASSANDRATOGCS.OUTPUT.PATH
Cloud Storage location for output files
--cassandratogcs.output.savemode {overwrite,append,ignore,errorifexists}
Output write mode (one of: append,overwrite,ignore,errorifexists) (Defaults to append)
--cassandratogcs.input.catalog.name CASSANDRATOGCS.INPUT.CATALOG.NAME
To provide a name for connection between Cassandra and GCS
--cassandratogcs.input.query CASSANDRATOGCS.INPUT.QUERY
Optional query for selective exports
--cassandratogcs.input.keyspace CASSANDRATOGCS.INPUT.KEYSPACE
CASSANDRA Cloud Storage Input Keyspace
--cassandratogcs.input.table CASSANDRATOGCS.INPUT.TABLE
CASSANDRA Cloud Storage Input Table
--cassandratogcs.output.chartoescapequoteescaping CASSANDRATOGCS.OUTPUT.CHARTOESCAPEQUOTEESCAPING
Sets a single character used for escaping the escape for the quote character. The default value is escape character when escape and quote characters are
different, \0 otherwise
--cassandratogcs.output.compression CASSANDRATOGCS.OUTPUT.COMPRESSION
--cassandratogcs.output.dateformat CASSANDRATOGCS.OUTPUT.DATEFORMAT
Sets the string that indicates a date format. This applies to date type
--cassandratogcs.output.emptyvalue CASSANDRATOGCS.OUTPUT.EMPTYVALUE
Sets the string representation of an empty value
--cassandratogcs.output.encoding CASSANDRATOGCS.OUTPUT.ENCODING
Decodes the CSV files by the given encoding type
--cassandratogcs.output.escape CASSANDRATOGCS.OUTPUT.ESCAPE
Sets a single character used for escaping quotes inside an already quoted value
--cassandratogcs.output.escapequotes CASSANDRATOGCS.OUTPUT.ESCAPEQUOTES
A flag indicating whether values containing quotes should always be enclosed in quotes. Default is to escape all values containing a quote character
--cassandratogcs.output.header CASSANDRATOGCS.OUTPUT.HEADER
Uses the first line of CSV file as names of columns. Defaults to True
--cassandratogcs.output.ignoreleadingwhitespace CASSANDRATOGCS.OUTPUT.IGNORELEADINGWHITESPACE
A flag indicating whether or not leading whitespaces from values being read/written should be skipped
--cassandratogcs.output.ignoretrailingwhitespace CASSANDRATOGCS.OUTPUT.IGNORETRAILINGWHITESPACE
A flag indicating whether or not trailing whitespaces from values being read/written should be skipped
--cassandratogcs.output.linesep CASSANDRATOGCS.OUTPUT.LINESEP
Defines the line separator that should be used for parsing. Defaults to \r, \r\n and \n for reading and \n for writing
--cassandratogcs.output.nullvalue CASSANDRATOGCS.OUTPUT.NULLVALUE
Sets the string representation of a null value
--cassandratogcs.output.quote CASSANDRATOGCS.OUTPUT.QUOTE
Sets a single character used for escaping quoted values where the separator can be part of the value. For reading, if you would like to turn off quotations, you
need to set not null but an empty string
--cassandratogcs.output.quoteall CASSANDRATOGCS.OUTPUT.QUOTEALL
--cassandratogcs.output.sep CASSANDRATOGCS.OUTPUT.SEP
Sets a separator for each field and value. This separator can be one or more characters
--cassandratogcs.output.timestampformat CASSANDRATOGCS.OUTPUT.TIMESTAMPFORMAT
Sets the string that indicates a timestamp with timezone format
--cassandratogcs.output.timestampntzformat CASSANDRATOGCS.OUTPUT.TIMESTAMPNTZFORMAT
Sets the string that indicates a timestamp without timezone format
This template requires the Spark Cassandra connector to be available in the Dataproc cluster. This can be downloaded using the following link. Another jar of POSIX handler is also required which can be downloaded from this link
Use the following command to download the jar-:
wget https://repo1.maven.org/maven2/com/datastax/spark/spark-cassandra-connector-assembly_2.12/3.2.0/spark-cassandra-connector-assembly_2.12-3.2.0.jar
wget https://repo1.maven.org/maven2/com/github/jnr/jnr-posix/3.1.8/jnr-posix-3.1.8.jar
Jar files named spark-cassandra-connector-assembly_2.12-3.2.0.jar and jnr-posix-3.1.8.jar would be downloaded, this can be passed to provide spark drivers and workers with cassandra connector class and its dependencies.
export GCP_PROJECT=<project_id>
export JARS="gs://path/to/jar/spark-cassandra-connector_2.12-3.2.0.jar,gs://path/to/jnr-posix-3.1.8.jar" # Pass the downloaded jar path
export REGION=<region>
./bin/start.sh \
-- --template=CASSANDRATOGCS \
--cassandratogcs.input.keyspace=<keyspace name> \
--cassandratogcs.input.table=<cassandra table name> \
--cassandratogcs.input.host=<cassandra host IP> \
--cassandratogcs.output.format=<output file format> \
--cassandratogcs.output.path=<gcs output bucket path> \
--cassandratogcs.output.savemode=<overwrite|append|ignore|errorifexists>
One can add additional property to submit query (If query is provided, don't provide keyspace and table). Please see format below-:
--cassandratogcs.input.catalog.name=<catalog-name>
--cassandratogcs.input.query="select * from <catalog-name>.<keyspace-name>.<table-name>"
Note-: cassandratogcs.input.catalog.name=<catalog-name> is used to provide a name to the connection with Cassandra. This name is used for querying purpose and has a default value of casscon if nothing is passed.
To query using default catalog name -:
--templateProperty cassandratogcs.input.query="select * from casscon.<keyspace-name>.<table-name>"
You can replace the casscon with your catalog name if it is passed. This is an important step to query the data from Cassandra. Additional details on usage of query can be found in this link.
After downloading the jar, a sample submission -:
export GCP_PROJECT=my-project
export REGION=us-central1
export SUBNET=projects/my-project/regions/us-central1/subnetworks/default
export JARS="gs://jar-bucket/spark-cassandra-connector-assembly_2.12-3.2.0.jar,gs://jar-bucket/jnr-posix-3.1.8.jar"
./bin/start.sh \
-- --template=CASSANDRATOGCS \
--cassandratogcs.input.keyspace=tk1 \
--cassandratogcs.input.table=emp \
--cassandratogcs.input.host=10.1X8.X.XX \
--cassandratogcs.output.format=csv \
--cassandratogcs.output.path=bucketname \
--cassandratogcs.output.savemode=overwrite \
--cassandratogcs.input.query="select emp_id from casscon.tk1.emp"
--cassandratogcs.output.header=false \
--cassandratogcs.output.timestampntzformat="yyyy-MM-dd HH:mm:ss"
Note: Make sure that either cassandratogcs.input.query or both cassandratogcs.input.keyspace and cassandratogcs.input.table is provided. Setting or not setting all three properties at the same time will throw an error.