Presto and the data.world Collector
Note
The latest version of the Collector is 2.137. To view the release notes for this version and all previous versions, please go here.
About the collector
Use this collector to harvest metadata for Presto tables and columns across the enterprise systems and make it searchable and discoverable in data.world.
Authentication supported
The collector supports basic authentication to Presto.
What is cataloged
The collector catalogs the following information.
Object | Information cataloged |
|---|---|
Columns | Name, Description, JDBC type, Column Type, Is Nullable, Default Value, Key type (Primary, foreign), column size, column index |
Table | Name, description, primary key, schema |
Views | Name, description, SQL definition |
Schema | Identifier |
Database | Type, name, identifier, server, port, environment, JDBC URL |
Relationships between objects
By default, the harvested metadata includes catalog pages for the following resource types. Each catalog page has a relationship to the other related resource types. If the metadata presentation for this data source has been customized with the help of the data.world Solutions team, you may see other resource pages and relationships.
Resource page | Relationship |
|---|---|
Table | Columns |
Columns | Table |
Setting up pre-requisites for running the collector
Make sure that the machine from where you are running the collector meets the following hardware and software requirements.
Item | Requirement |
|---|---|
Hardware | |
RAM | 8 GB |
CPU | 2 Ghz processor |
Software | |
Docker | Click here to get Docker. |
Java Runtime Environment | OpenJDK 17 is supported and available here. |
data.world specific objects | |
Dataset | You must have a ddw-catalogs (or other) dataset set up to hold your catalog files when you are done running the collector. |
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:
On the Organization profile page, go to the Settings tab > Metadata collectors section.
Click the Help me set up a collector button.
On the On-prem collector setup prerequisites screen, read the pre-requisites and click Next.
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.
On the Choose metadata collector type you would like to setup screen, select Presto. Click Next.
On the Configure a new on-premises Presto Collector screen, set the following properties and click Next.
On the next screen, set the following properties and click Next.
Table 3.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
Database Id
-D= <databseid>
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
Username
-u= <user>
--user= <user>
The username to use to connect to the database.
Yes
Password
-P= <password>
--password= <password>
The environment variable of the password used to connect to the database.
Yes
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 to help differentiate it from other environments.
No
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>
The name of the database schema to catalog.
Yes (if --all-schema is not set)
On the next screen, set the following properties and click Next.
Table 4.Field name
Corresponding parameter name
Description
Required?
JDBC Properties
--jdbc-property= <driverProperties>
JDBC driver properties to pass through to driver connection, as name=value. Separate the name=value pairs with a semicolon (;). For example, property1=value1;property2=value2
No
On the Finalize your Presto 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.
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.
Sample YAML file.
The Presto command screen gives you the command to use for running the collector using the YAML file.
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 5.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
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
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.
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
Go to the server where you have setup docker to run the collector.
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.
Place the YAML file generated from the Collector wizard to the correct directory.
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=${HOME}/dwcc datadotworld/dwcc:2.124 \ catalog-presto --agent=8bank-catalog-sources --site=solutions --no-log-upload=false \ --upload=true --api-token=${DW_AUTH_TOKEN} --output=/dwcc-output \ --name=8bank-catalog-sources-collection --upload-location=ddw-catalogs \ --server=8bank--server --database=8bank--database --user=8bank--username \ --password=${DW_PRESTO_PASSWORD} --all-schemas=trueThe collector automatically uploads the file to the specified dataset and you can also find the output at the location you specified while running the collector.
At a later point, if you download a newer version of collector from docker, you can edit the collector version in the generated command to run the collector with the newer version.
Running collector without the YAML file
Go to the server where you have setup docker to run the collector.
Make sure you have download the version of collectors from here. This version should match the version of the collector specified in the command you are using to run the collector.
From the command line, run the command generated from the application. Here is a sample command.
Caution
Note that is just a sample command for showing the syntax. You must generate the command specific to your setup from the application UI.
docker run -it --rm --mount type=bind,source=${HOME}/dwcc,target=/dwcc-output \ --mount type=bind,source=${HOME}/dwcc,target=${HOME}/dwcc -e DW_AUTH_TOKEN=${DW_AUTH_TOKEN} \ -e DW_PRESTO_PASSWORD=${DW_PRESTO_PASSWORD} datadotworld/dwcc:2.124 \ --config-file=/dwcc-output/config-presto.ymlThe 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.
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.
Collector runtime and troubleshooting
The catalog collector may run in several seconds to many minutes depending on the size and complexity of the system being crawled. If the catalog collector runs without issues, you should see no output on the terminal, but a new file that matching *.dwec.ttl should be in the directory you specified for the output. If there was an issue connecting or running the catalog collector, there will be either a stack trace or a *.log file. Both of those can be sent to support to investigate if the errors are not clear. A list of common issues and problems encountered when running the collectors is available here.
Overview
Some enterprise systems support the use of Secure Sockets Layer (SSL) encrypted communications on all external traffic. If you are harvesting metadata from a source system that requires SSL, you will need to add a CA certificate or self-signed certificate.
Obtaining the Custom SSL Certificate
Obtain the root certificate for your source system issued by your company. Typically your system administrator should be able to provide you with this.
Extending Docker to use custom SSL certificates
If the collector is run via Docker, extend the Docker image and install the custom certificate.
STEP 1: Prepare the Docker File
First, prepare a Dockerfile with the instructions for Docker to install the custom certificate and extend the Docker image.
Ensure you are on the machine where you have downloaded the Docker Image and plan to execute the Collector.
In a directory create the new Dockerfile with the following parameters for your custom SSL Certificate:
FROM datadotworld/dwcc:<collector_version> ADD ./<custom_certificate_file_path> <custom_certificate_file_name> RUN keytool -importcert -alias startssl -cacerts -storepass changeit -noprompt -file <custom_certificate_file_name>
Replace <collector_version> with the version of the Collector you want to use (For example, datadotworld/dwcc:2.120)
Replace <custom_certificate_file_path> with the path to the custom SSL Certificate.
Replace <custom_certificate_file_name> with the name of your custom SSL Certificate file.
For example, the command will look like:
FROM datadotworld/dwcc:2.120 ADD ./ ca.der certificate RUN keytool -importcert -alias startssl -cacerts -storepass changeit -noprompt -file certificate
STEP 2: Install the certificate and extend the docker image
Next, execute the the Dockerfile to install the certificate and extend the data.world Collector Docker Image.
Using your terminal of choice, ensure you are in the directory containing the Dockerfile created in step 1.
Next, create the new extended Docker image, called dwcc-cert in this example, by executing the following command:
docker build -t dwcc-cert .
Important things to note:
The command must be all lowercase.
The command must include the period (.) at the end, which directs Docker to use the local directory for the Dockerfile created above.
For the new image, the command uses the name dwcc-cert You can change the name if you want.
STEP 3: Run collector using the custom certificate
Finally, run the collector using the custom Certificate.
Get the standard docker run command for the Data Source you are collecting from.
Change the docker run command to use dwcc-cert image instead of dwcc image.
Sample command for Tableau.
docker run -it --rm --mount type=bind,source=/tmp,target=/dwcc-output \ --mount type=bind,source=/tmp,target=/app/log dwcc-cert \ catalog-tableau --tableau-api-base-url <baseUrl> \ --tableau-password <password> --tableau-username <username> \ -a <account> -n <catalogName> -o "/dwcc-output"
If you are using YAML file for running the collector, edit the command to use dwcc-cert image instead of dwcc image.
docker run -it --rm --mount type=bind,source=${HOME}/dwcc,target=/dwcc-output \ --mount type=bind,source=${HOME}/dwcc,target=${HOME}/dwcc -e DW_AUTH_TOKEN=${DW_AUTH_TOKEN} \ -e DW_TABLEAU_PASSWORD=${DW_TABLEAU_PASSWORD} dwcc-cert \ --config-file=/dwcc-output/config-tableau.yml
Adding custom SSL certificates when using jar
If the collector is run via jar, add the certificate to the JVM truststore.
From the terminal, navigate to the directory containing the certificate.
Run the following command to add the SSL certificate to the truststore:
keytool -importcert -alias startssl -cacerts -storepass changeit -noprompt -file <custom_certificate_file_path>
Replace <custom_certificate_file_path> with the path to the custom SSL Certificate.
For example, the command will look like:
keytool -importcert -alias startssl -cacerts -storepass changeit -noprompt -file ca.der
Finally, run the collector using the original jar file command. Note that this command does not need any modifications.
Troubleshooting SSL certificate issues
Issue
The following error occurs while running the collector:
Caused by: javax.ws.rs.ProcessingException: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Description
There was an issue connecting to the source system using the SSL certificate.
Solution
Check to make sure the SSL certificate has not expired.
Ensure you have the correct SSL certificate for the source system.
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.