feat(ingest/cassandra): Add support for Cassandra as a source

[sagar-salvi-apptware]

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[jjoyce0510]

Things to confirm:

• Platform Instance is supported, and is included when generating keyspace (container) AND table (dataset) URNs
• Make sure that UDT column types are correctly flattened and supported
• Make sure the column type mapping matches the following

Cassandra Data Type	DataHub Data Type
ascii	StringType
bigint	NumberType
blob	BytesType
boolean	BooleanType
counter	NumberType
date	DateType
decimal	NumberType
double	NumberType
float	NumberType
inet	StringType
int	NumberType
list	ArrayType
map	MapType
set	ArrayType
smallint	NumberType
text	StringType
time	TimeType
timestamp	DateType
timeuuid	StringType
tinyint	NumberType
tuple	ArrayType
uuid	StringType
varchar	StringType
varint	NumberType
frozen<map<text, text>>	MapType
frozen<list>	ArrayType
frozen<set>	ArrayType

[jjoyce0510]

set -> ArrayType list -> ArrayType
map<?> -> MapType

And UDT -> Flattened structure

[jjoyce0510]

Views & Tables should have the same aspects

• Data Platform Instance
• Sub Types
• Dataset Properties
• Container
• Browse Paths V2

And ensure we have table + column comments as description fields.

.....And

Views have

• View Properties

[jjoyce0510]

Table + Column Comments should be QA'd locally.

[jjoyce0510]

Also please make sure error handling is clear. And try-excepts are around areas where we need. This connector should only fail in known cases. We should not have ANY uncaught exceptions!

[mayurinehate]

Looking good

[mayurinehate]

Can replace this check as if self.config.cloud_config if we remove empty defaults in config as suggested earlier.

[sagar-salvi-apptware]

We have additional optional config so this check invalid right? self.config.cloud validated token and bundle path

    connect_timeout: int = Field(
        default=60,
        description="Timeout in seconds for establishing new connections to Cassandra.",
    )

    request_timeout: int = Field(
        default=60, description="Timeout in seconds for individual Cassandra requests."
    )

[mayurinehate]

Does cassandra provide column order in its system view of columns? Some systems do provide it, and if so we should honour it rather than sorting by name.

[sagar-salvi-apptware]

It only applied for PRIMARY KEY not for others.

[mayurinehate]

If possible, this would be great -> https://github.com/datahub-project/datahub/pull/9680/files#r1460632601

[sagar-salvi-apptware]

I have removed the commented part