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Running the Snowflake collector

Note

The latest version of the Collector is 2.158. To view the release notes for this version and all previous versions, please go here.

Generating the command or YAML file

This section walks you through the process of generating the command or YAML file for running the collector from Windows or Linux or MAC OS.

To generate the command or YAML file:

  1. On the Organization profile page, go to the Settings tab > Metadata collectors section.

  2. Click the Help me set up a collector button.

  3. On the On-prem collector setup prerequisites screen, read the pre-requisites and click Next.

  4. On the On which platform will this collector execute? screen, select if you will be running the collector on Windows or Mac OS or Linux. This will determine the format of the YAML and CLI that is generated in the end. Click Next.

    general_01.png
  5. On the Choose metadata collector type you would like to setup screen, select Snowflake. Click Next.

  6. On the Configure a new on premises Snowflake Collector screen, set the following properties and click Next.

    snowflake_01.png
  7. On the next screen, set the following properties and click Next.

    snowflake_02.png

    Important

    Snowflake is case-sensitive so database and schema names need to be specified with the same case as they are in Snowflake.

    Table 2.

    Field name

    Corresponding parameter name

    Description

    Required

    Server

    -s= <server>

    --server= <server> 

    The hostname of the database server to connect to.

    Yes

    Server port

    -p= <port>

    --port= <port>

    The port of the database server (if not the default).

    No

    Database

    -d= <database>

    --database= <database>

    The name of the database to connect to.

    Yes

    Snowflake role

    -r= <role>

    --role= <role>

    The role used to execute the query.

    Yes

    Authentication

    Select from one of the following options:

    • Authenticate with a username & password

    • Authenticate using a private key file

    Yes

    Authenticate with a username & password

    Username

    -u= <user>

    --user= <user>

    The username used to connect to the database.

    Yes

    Password

    -P= <password>

    --password= <password> 

    The environment variable of the password used to connect to the database. Default value is an environment variable ${DW_SNOWFLAKE_PASSWORD}

    Yes

    Authenticate using a private key file

    Location of private key file

    --private-key-file= <PrivateKeyFile>

    The private key file to use for authentication. You will need to mount a local directory containing the private-key-file with a directory on the Docker container. The --private-key-file should be the path to the directory on the container with the private key. For instance, for a private-key-file called rsa_key.p8, add to the CLI command --mount type=bind,source=/tmp,target=/snowflake-key and set --private-key-file="/snowflake-key/rsa_key.p8"

    Yes

    Env Variable Password of your private key file

    --private-key-file-password= <PrivateKeyFilePassword>

    The password for the private key file, if the key is encrypted and a password was set. Default value is an environment variable ${DW_SNOWFLAKE_PK_PASSWORD}.

    Yes

    Schemas to collect

    Select from one of the following options: Collect all schema, Specify which schema to collect

    Yes

    Collect all schema

    -A

    --all-schemas

    Catalog all schemas to which the user has access.

    Yes

    (if --schema is not set)

    Specify which schema to collect

    -S= <databaseSchema>

    --schema= <databaseSchema>

    Select this option and then specify the names of the database schema to be catalog.

    Yes

    (if --all-schemas is not set)

    Information schema

    --include-information-schema

    Set this if you want to also collect this Information schema for the database. You can set this option only when you have selected the Collect all schema (--all-schemas) option.

    No



  8. On the next screen, set the following optional properties and click Next.

    Table 3.

    Field name

    Corresponding parameter name

    Description

    Required?

    Disable lineage collection

    --disable-lineage-collection

    Skip harvesting of intra-database lineage metadata.

    No

    Collect Snowflake tag information

    --tag-collection

    Harvest information about Snowflake tags

    No

    Enable sample string values collection

    --sample-string-values

    to enable harvesting of sample values and histograms for columns containing string data

    No

    Collect Snowflake policy information

    --policy-collection

    Harvest information about Snowflake masking and row-access policies

    No

    Collect Snowflake table usage information

    --table-usage-collection

    Harvests metadata about Snowflake table usage in queries (popularity). Calculates, for each table in the database being harvested, the percentage of tables in the database that have been queried no fewer times than the subject table.

    No

    Table usage lookback days

    --table-usage-lookback

    Number of days in the past at which to begin harvesting table usage (default=7 days).

    No

    Enable column statistics collection

    --enable-column-statistics

    To enable harvesting of column statistics (i.e., data profiling)

    No

    Target sample size for Profiling

    --target-sample-size= <targetSampleSize>

    To control the number of rows sampled for computation of column statistics and string-value histograms. For example, to sample 1000 rows, set the parameter as: --target-sample-size=1000

    No

    Snowflake warehouse

    -w= <warehouse>

    --warehouse= <warehouse>

    The Snowflake warehouse to use when connecting (user's assigned default if not specified)

    No

    Server environment

    -e= <environment>

    --environment= <environment>

    If your provided server name is localhost, use this to give a friendly name to the environment in which your database server runs. It helps differentiate it from other environments.

    No

    Database ID

    -D= <databaseId>

    --database-id= <databaseId>

    A unique identifier for this database - will be used to generate the ID for the database. This is optional, you only need to provide this if the database name used for the connection is not sufficiently unique to completely identify the database.

    No

    JDBC Properties

    --jdbc-property= <driverProperties> 

    JDBC driver properties to pass through to driver connection.

    No



  9. On the next screen, provide the Collector configuration name. This is the name used to save the configuration details. The configuration is saved and made available on the Metadata collectors summary page from where you can edit or delete the configuration at a later point. Click Save and Continue.

  10. On the Finalize your Snowflake Collector configuration screen, you are notified about the environment variables and directories you need to setup for running the collector. Select if you want to generate a Configuration file( YAML) or Command line arguments (CLI). Click Next.

    Important

    You must ensure that you have set up these environment variables and directories before you run the collector.

  11. The next screen gives you an option to download the YAML configuration file or copy the CLI command. Click Done. If you are generating a YAML file, click Next.

  12. The Snowflake command screen gives you the command to use for running the collector using the YAML file.

  13. You will notice that the YAML/CLI has following additional parameters that are automatically set for you.

    Important

    Except for the collector version, you should not change the values of any of the parameter listed here.

    Table 4.

    Parameter name

    Details

    Required?

    -a= <agent>

    --agent= <agent>

    --account= <agent>

    The ID for the data.world account into which you will load this catalog - this is used to generate the namespace for any URIs generated.

    Yes

    --site= <site>

    This parameter should be set only for Private instances. Do not set it for public instances and single-tenant installations. Required for private instance installations.

    Yes (required for private instance installations)

    -U

    --upload

    Whether to upload the generated catalog to the  organization account's catalogs dataset.

    Yes

    -L

    --no-log-upload

    Do not upload the log of the Collector run to the organization account's catalogs dataset.

    Yes

    dwcc: <CollectorVersion>

    The version of the collector you want to use (For example, datadotworld/dwcc:2.113)

    Yes



  14. Add the following additional parameter to test run the collector.

    • --dry-run If specified, the collector does not actually harvest any metadata, but just checks the database connection parameters provided by the user and reports success or failure at connecting.

Verifying environment variables and directories

  1. Verify that you have set up all the required environment variables that were identified by the Collector Wizard before running the collector. Alternatively, you can set these credentials in a credential vault and use a script to retrieve those credentials.

  2. Verify that you have set up all the required directories that were identified by the Collector Wizard.

Running the collector

Important

Before you begin running the collector make sure you have the correct version of collectors downloaded and available.

Running collector using YAML file

  1. Go to the server where you have setup docker to run the collector.

  2. Make sure you have download the correct version of collectors. This version should match the version of the collector specified in the command you are using to run the collector.

  3. Place the YAML file generated from the Collector wizard to the correct directory.

  4. From the command line, run the command generated from the application for executing the YAML file.

    Caution

    Note that is just a sample command for showing the syntax. You must generate the command specific to your setup from the application UI.

    docker run -it --rm --mount type=bind,source=${HOME}/dwcc,target=/dwcc-output \
      --mount type=bind,source=${HOME}/dwcc,target=${HOME}/dwcc --mount type=bind,source=${HOME}/dwcc-drivers,target=/usr/src/dwcc-config/lib \
      -e DW_AUTH_TOKEN=${DW_AUTH_TOKEN} -e DW_SNOWFLAKE_PASSWORD=${DW_SNOWFLAKE_PASSWORD} \
      datadotworld/dwcc:2.124 --config-file=/dwcc-output/config-snowflake.yml
  5. The collector automatically uploads the file to the specified dataset and you can also find the output at the location you specified while running the collector.

  6. At a later point, if you download a newer version of collector from docker, you can edit the collector version in the generated command to run the collector with the newer version.

Running collector without the YAML file

  1. Go to the server where you have setup docker to run the collector.

  2. Make sure you have download the version of collectors from here. This version should match the version of the collector specified in the command you are using to run the collector.

  3. From the command line, run the command generated from the application. Here is a sample command.

    Caution

    Note that is just a sample command for showing the syntax. You must generate the command specific to your setup from the application UI.

    docker run -it --rm --mount type=bind,source=${HOME}/dwcc,target=/dwcc-output \
      --mount type=bind,source=${HOME}/dwcc,target=${HOME}/dwcc --mount type=bind,source=${HOME}/dwcc-drivers,target=/usr/src/dwcc-config/lib \
      datadotworld/dwcc:2.124 catalog-snowflake --agent=8bank-catalog-sources \
      --site=solutions --no-log-upload=false --upload=true --api-token=${DW_AUTH_TOKEN} \
      --output=/dwcc-output --name=8bank-catalog-sources-collection \
      --upload-location=ddw-catalogs --server=cu440.snowflakecompu.com \
      --database=SAMPLE_DB --user=catalogstudent1 --password=${DW_SNOWFLAKE_PASSWORD} \
      --all-schemas=true --include-information-schema=false --policy-collection=true \
      --tag-collection=true --disable-lineage-collection=true --enable-column-statistics=true \
      --sample-string-values=false
  4. The collector automatically uploads the file to the specified dataset and you can also find the output at the location you specified while running the collector.

  5. At a later point, if you download a newer version of collector from docker, you can edit the collector version in the generated command to run the collector with the newer version.

Automating updates to your metadata catalog

Keep your metadata catalog up to date using cron, your Docker container, or your automation tool of choice to run the catalog collector on a regular basis. Considerations for how often to schedule include:

  • Frequency of changes to the schema

  • Business criticality of up-to-date data

For organizations with schemas that change often and where surfacing the latest data is business critical, daily may be appropriate. For those with schemas that do not change often and which are less critical, weekly or even monthly may make sense. Consult your data.world representative for more tailored recommendations on how best to optimize your catalog collector processes.

Managing collector runs and configuration details