OCF Connector for Impala on CDP: Overview¶
Alation Cloud Service Applies to Alation Cloud Service instances of Alation
Customer Managed Applies to customer-managed instances of Alation
Compatible with Alation version 2022.4 or later
The OCF connector for Impala on Cloudera Data Platform (CDP) was developed by Alation and earlier certified only for on-premise CDP.
From version 2.0.0, this connector also supports Public Cloud CDP Distribution and Private Cloud CDP Distribution.
To download the Impala on CDP OCF connector package, go to the Alation Connector Hub available from the Customer Portal. Go to Customer Portal > Connectors > Alation Connector Hub. Only Alation users with access to the Customer Portal can access the Alation Connector Hub. If you don’t have access to the Customer Portal, contact Alation Support.
This connector should be used to catalog Impala on CDP as a data source in Alation. The connector catalogs Impala objects such as schemas, tables, views, and columns. It enables end-users to search and find the Impala metadata from the Alation user interface. After metadata is extracted, it is represented in the Alation catalog as a hierarchy of catalog pages under the parent data source. Alation users can leverage the full catalog functionality to search for and find the extracted metadata, curate the corresponding catalog pages, create documentation about the data source, and exchange information about it.
Team¶
The following administrators are required to install this connector:
Alation administrator
Installs the connector
Creates and configures an Impala data source in the catalog
Performs initial extraction and prepares the data source for Alation users.
Impala administrator
Creates a service account and grants it the required privileges
Provides the JDBC URI
Provides access to the metastore server to extract metadata
Provides access to the query log history directory on HDFS or Amazon S3.
Scope¶
The table below describes which metadata objects are extracted by the connector and which catalog functionality is supported.
Feature |
Scope |
Availability |
|---|---|---|
Authentication |
||
Basic authentication |
Authentication with a service account created on the database that uses a username and password |
Yes |
LDAP |
Authentication with a database service account that is an LDAP account in an organization’s network |
Yes |
SSL |
Database connection over SSL |
Yes |
Kerberos |
Support for Kerberos authentication |
Yes |
Keytab |
Support for Kerberos with keytabs |
Yes |
SSO |
SSO authentication with an identity provider application |
No |
Metadata Extraction (MDE) |
||
Default MDE |
Extraction of metadata based on Metastore API |
Yes |
Custom query-based MDE |
Extraction of metadata based on extraction queries provided by a user |
No |
Extracted metadata objects |
||
Data source |
Data source object in Alation that is parent to extracted metadata |
Yes |
Schemas |
List of schemas |
Yes |
Tables |
List of tables |
Yes |
Columns |
List of columns |
Yes |
Column data types |
Column data types |
Yes |
Views |
List of views |
Yes |
Source comments |
Source comments |
Yes |
Primary keys |
Primary key information for extracted tables |
No |
Foreign keys |
Foreign key information for extracted tables |
No |
Functions |
Function metadata |
No |
Function definitions |
Function definition metadata |
No |
Sampling and Profiling (Sampling and profiling is not available for complex data types) |
||
Table sampling |
Retrieval of data samples from extracted tables |
Yes |
Column sampling |
Retrieval of data samples from extracted columns |
Yes |
Deep column profiling |
Profiling of columns with the calculation of value distribution stats |
Yes |
Dynamic profiling |
Ability for individual users to connect with their own database accounts to retrieve table and column samples and profiles |
Yes |
Custom query-based table sampling |
Ability to use custom queries for sampling specific tables |
Yes |
Custom query-based column sampling |
Ability to use custom queries for profiling specific columns |
Yes |
Query Log Ingestion (QLI) |
||
API-based QLI |
Ingestion of query history based on Impala audit file that contains query history data |
Yes |
Query-based QLI |
Ingestion of query history based on a custom query history extraction query |
No |
JOINs and filters |
Calculation of JOIN and filter information based on ingested query history |
Yes |
Predicates |
Ability to parse predicates in ingested queries |
Yes |
Lineage |
||
Automatic lineage generation |
Auto-calculation of lineage based on query history ingested from QLI, MDE, and Compose queries |
Yes |
Column-level lineage |
Calculation of lineage at column level |
No |
Compose |
||
Customer-managed (on-prem) Alation instances |
Compose on on-prem Alation instances |
Yes |
Alation Cloud Service instances, connection without Agent |
Compose for data sources connected without Alation Agent |
Yes |
Alation Cloud Service instances, connection via Agent |
Compose for data sources connected through Alation Agent |
No |
Kerberos authentication with Compose |
Authentication in Compose through Kerberos |
No |
SSO authentication in Compose |
Authentication in Compose with SSO credentials |
No |
Limitations¶
For Impala OCF Connector version 2.0.0, Compose is supported only with Alation version 2023.3.3.2 or later.
Compose doesn’t work with Kerberos authentication.
Sampling and profiling is not available for complex data types.
QLI is not supported for Cloudera Data Warehouse(CDW) in both Private and Public Cloud.
Data upload into columns with complex data types is not supported.