Skip to content
Merged
Show file tree
Hide file tree
Changes from 5 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 13 additions & 6 deletions plugins/spark/README.md
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,12 @@ and depends on iceberg-spark-runtime 1.8.1.

# Build Plugin Jar
A task createPolarisSparkJar is added to build a jar for the Polaris Spark plugin, the jar is named as:
`polaris-iceberg-<icebergVersion>-spark-runtime-<sparkVersion>_<scalaVersion>-<polarisVersion>.jar`. For example:
`polaris-iceberg-1.8.1-spark-runtime-3.5_2.12-0.10.0-beta-incubating-SNAPSHOT.jar`.

- `./gradlew :polaris-spark-3.5_2.12:createPolarisSparkJar` -- build jar for Spark 3.5 with Scala version 2.12.
- `./gradlew :polaris-spark-3.5_2.13:createPolarisSparkJar` -- build jar for Spark 3.5 with Scala version 2.13.

The result jar is located at plugins/spark/v3.5/build/<scala_version>/libs after the build.

# Start Spark with Local Polaris Service using built Jar
Expand All @@ -51,13 +57,12 @@ bin/spark-shell \
--conf spark.sql.extensions=org.apache.iceberg.spark.extensions.IcebergSparkSessionExtensions,io.delta.sql.DeltaSparkSessionExtension \
--conf spark.sql.catalog.spark_catalog=org.apache.spark.sql.delta.catalog.DeltaCatalog \
--conf spark.sql.catalog.<catalog-name>.warehouse=<catalog-name> \
--conf spark.sql.catalog.<catalog-name>.header.X-Iceberg-Access-Delegation=true \
--conf spark.sql.catalog.<catalog-name>.header.X-Iceberg-Access-Delegation=vended-credentials \
--conf spark.sql.catalog.<catalog-name>=org.apache.polaris.spark.SparkCatalog \
--conf spark.sql.catalog.<catalog-name>.uri=http://localhost:8181/api/catalog \
--conf spark.sql.catalog.<catalog-name>.credential="root:secret" \
--conf spark.sql.catalog.<catalog-name>.scope='PRINCIPAL_ROLE:ALL' \
--conf spark.sql.catalog.<catalog-name>.token-refresh-enabled=true \
--conf spark.sql.catalog.<catalog-name>.type=rest \
--conf spark.sql.sources.useV1SourceList=''
```

Expand All @@ -72,24 +77,26 @@ bin/spark-shell \
--conf spark.sql.extensions=org.apache.iceberg.spark.extensions.IcebergSparkSessionExtensions,io.delta.sql.DeltaSparkSessionExtension \
--conf spark.sql.catalog.spark_catalog=org.apache.spark.sql.delta.catalog.DeltaCatalog \
--conf spark.sql.catalog.polaris.warehouse=<catalog-name> \
--conf spark.sql.catalog.polaris.header.X-Iceberg-Access-Delegation=true \
--conf spark.sql.catalog.polaris.header.X-Iceberg-Access-Delegation=vended-credentials \
--conf spark.sql.catalog.polaris=org.apache.polaris.spark.SparkCatalog \
--conf spark.sql.catalog.polaris.uri=http://localhost:8181/api/catalog \
--conf spark.sql.catalog.polaris.credential="root:secret" \
--conf spark.sql.catalog.polaris.scope='PRINCIPAL_ROLE:ALL' \
--conf spark.sql.catalog.polaris.token-refresh-enabled=true \
--conf spark.sql.catalog.polaris.type=rest \
--conf spark.sql.sources.useV1SourceList=''
```

# Limitations
The Polaris Spark client supports catalog management for both Iceberg and Delta tables, it routes all Iceberg table
requests to the Iceberg REST endpoints, and routes all Delta table requests to the Generic Table REST endpoints.

Following describes the current limitations of the Polaris Spark client:
The Spark Client requires at least delta 3.2.1 to work with Delta tables, which requires at least Apache Spark 3.5.3.
Following describes the current functionality limitations of the Polaris Spark client:
1) Create table as select (CTAS) is not supported for Delta tables. As a result, the `saveAsTable` method of `Dataframe`
is also not supported, since it relies on the CTAS support.
2) Create a Delta table without explicit location is not supported.
3) Rename a Delta table is not supported.
4) ALTER TABLE ... SET LOCATION/SET FILEFORMAT/ADD PARTITION is not supported for DELTA table.
5) For other non-iceberg tables like csv, there is no specific guarantee provided today.
5) For other non-Iceberg tables like csv, there is no specific guarantee provided today.

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

there is no specific guarantee provided today

What does this mean? If we mean that it may work but we don't officially support it, let's word it accordingly.

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What does "officially support" mean?

It may, or may not work... we don't provide any guarantee about whether or not it works. I think we might just want to not even mention it.

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think let me make it very explicit that it is not supported for now.

6) TABLE_WRITE_DATA privilege is not supported for Delta Table.
7) Credential Vending is not supported for Delta Table.

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Does this imply that writes to Delta Tables are not supported?

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It's more complicated than that; it implies exactly what it says. With Delta, the catalog doesn't take over the responsibility of the writes. But that doesn't mean that the client can't write to the Delta table. However, it can't use vended credentials to do so.

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actually, those are our Polaris service limitations, not really client limitations, it might be better to introduce another generic table support page and put that limitation there. I removed it from the polaris spark client for now

156 changes: 156 additions & 0 deletions site/content/in-dev/unreleased/polaris-spark-client.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,156 @@
---
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
#
Title: Polaris Spark Client
type: docs
weight: 400

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit: "Entities" page is also at weight 400. We should, ideally, not have multiple pages at the same weight so that it's not confusing.

But in other thoughts: Do we think this belongs between "Entities" and "Telemetry" in the drop down? Personally, I think putting it between "Configuring Polaris" and "Deploying in Production" makes more sense. Or even creating a new folder for how to use new features.

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

+1 to a new folder

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

We could create a new folder once we got more than one client, e.g. spark and Trino clients.

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think a new folder seems to much for now, i moved after Deploying in Production, since the spark client can only be used after the polaris is deployed

---

Apache Polaris now provides Catalog support for Generic Tables (non-iceberg tables), please check out
the [Catalog API Spec]({{% ref "polaris-catalog-service" %}}) for Generic Table API specs.

Along with the Generic Table Catalog support, Polaris is also releasing a Spark Client, which helps to
provide an end-to-end solution for Apache Spark to manage Delta tables using Polaris.

Note the Polaris Spark Client is able to handle both Iceberg and Delta tables, not just Delta.

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Q: do parquet/csv tables work?

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I briefly tested scv manually before, basic operations like create, insert, drop works, alter doesn't work. I haven't tested parquet yet.
I don't want to do specific commitment for those table formats yet before we do more detailed testing.

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

We should probably file an issue for this


This page documents how to build and use the Polaris Spark Client directly with the source repo.

@flyrain flyrain May 1, 2025

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can we talk about how to use the jar(line 89 to line 145) first, then goes to build details? I believe most of users mainly care about the usage once we release the client jar.

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I adjusted the order, and have section

Start Spark against a deployed Polaris service

and

Connecting with Spark using local Polaris Spark client


## Prerequisite
1. Check out the polaris repo
```shell
cd ~
git clone https://github.com/apache/polaris.git
```
2. Spark with version >= 3.5.3 and <= 3.5.5, recommended with 3.5.5.

@flyrain flyrain May 1, 2025

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
2. Spark with version >= 3.5.3 and <= 3.5.5, recommended with 3.5.5.
2. Download a Spark distribution with version >= 3.5.3 and <= 3.5.5, recommended with 3.5.5.

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is not needed for Quick Start, so i moved it under 'Start Spark against a deployed Polaris service' now

```shell
cd ~
wget https://archive.apache.org/dist/spark/spark-3.5.5/spark-3.5.5-bin-hadoop3.tgz
mkdir spark-3.5
tar xzvf spark-3.5.5-bin-hadoop3.tgz -C spark-3.5 --strip-components=1
cd spark-3.5
```

All Spark Client code is available under `plugins/spark` of the polaris repo.

## Quick Start with Local Polaris Service
If you want to quickly try out the functionality with a local Polaris service, you can follow the instructions
in `plugins/spark/v3.5/getting-started/README.md`.

The getting-started will start two containers:
1) The `polaris` service for running Apache Polaris using an in-memory metastore
2) The `jupyter` service for running Jupyter notebook with PySpark (Spark 3.5.5 is used)

The notebook `SparkPolaris.ipynb` provided under `plugins/spark/v3.5/getting-started/notebooks` provides examples
with basic commands, includes:
1) Connect to Polaris using Python client to create a Catalog and Roles
2) Start Spark session using the Polaris Spark Client
3) Using Spark to perform table operations for both Delta and Iceberg

## Start Spark against a deployed Polaris Service
If you want to start Spark with a deployed Polaris service, you can follow the instructions below.

Before starting, make sure the service deployed is up-to-date, and that Spark 3.5 with at least version 3.5.3 is installed.

### Build Spark Client Jars
The polaris-spark project provides a task createPolarisSparkJar to help building jars for the Polaris Spark client,
The built jar is named as:
`polaris-iceberg-<icebergVersion>-spark-runtime-<sparkVersion>_<scalaVersion>-<polarisVersion>.jar`.

For example: `polaris-iceberg-1.8.1-spark-runtime-3.5_2.12-0.10.0-beta-incubating-SNAPSHOT.jar`.

Run the following commands to build a Spark Client jar that is compatible with Spark 3.5 and Scala 2.12.
```shell
cd ~/polaris
./gradlew :polaris-spark-3.5_2.12:createPolarisSparkJar
```
If you want to build a Scala 2.13 compatible jar, you can use the following command:
- `./gradlew :polaris-spark-3.5_2.13:createPolarisSparkJar`

The result jar is located at `plugins/spark/v3.5/build/<scala_version>/libs` after the build. You can also copy the
corresponding jar to any location your Spark will have access.

### Connecting with Spark Using the built jar
The following CLI command can be used to start the spark with connection to the deployed Polaris service using

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

"start Apache Spark with a connection"

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Capitalized the Spark, since I have Apache Spark at the very beginning, i don't think we need to repeat Apache Spark everywhere

the Polaris Spark client jar.

```shell
bin/spark-shell \
--jars <path-to-spark-client-jar> \
--packages org.apache.hadoop:hadoop-aws:3.4.0,io.delta:delta-spark_2.12:3.3.1 \
--conf spark.sql.extensions=org.apache.iceberg.spark.extensions.IcebergSparkSessionExtensions,io.delta.sql.DeltaSparkSessionExtension \
--conf spark.sql.catalog.spark_catalog=org.apache.spark.sql.delta.catalog.DeltaCatalog \
--conf spark.sql.catalog.<spark-catalog-name>.warehouse=<polaris-catalog-name> \
--conf spark.sql.catalog.<spark-catalog-name>.header.X-Iceberg-Access-Delegation=vended-credentials \
--conf spark.sql.catalog.<spark-catalog-name>=org.apache.polaris.spark.SparkCatalog \
--conf spark.sql.catalog.<spark-catalog-name>.uri=<polaris-service-uri> \
--conf spark.sql.catalog.<spark-catalog-name>.credential='<client-id>:<client-secret>' \
--conf spark.sql.catalog.<spark-catalog-name>.scope='PRINCIPAL_ROLE:ALL' \
--conf spark.sql.catalog.<spark-catalog-name>.token-refresh-enabled=true
```

Replace `path-to-spark-client-jar` to where the built jar is located. The `spark-catalog-name` is the catalog name you
will use with spark, and `polaris-catalog-name` is the catalog name used by Polaris service, for simplicity, you can use
the same name. Replace the `polaris-service-uri`, `client-id` and `client-secret` accordingly, you can refer to
[Using Polaris]({{% ref "getting-started/using-polaris" %}}) for more details about those fields.

Or you can create a spark session start the connection, following is an example with pyspark
```python
from pyspark.sql import SparkSession

spark = SparkSession.builder
.config("spark.jars", <path-to-spark-client-jar>)
.config("spark.jars.packages", "org.apache.hadoop:hadoop-aws:3.3.4,io.delta:delta-spark_2.12:3.3.1")
.config("spark.sql.catalog.spark_catalog", "org.apache.spark.sql.delta.catalog.DeltaCatalog")
.config("spark.sql.extensions", "org.apache.iceberg.spark.extensions.IcebergSparkSessionExtensions,io.delta.sql.DeltaSparkSessionExtension")
.config("spark.sql.catalog.<spark-catalog-name>", "org.apache.polaris.spark.SparkCatalog")
.config("spark.sql.catalog.<spark-catalog-name>.uri", <polaris-service-uri>)
.config("spark.sql.catalog.<spark-catalog-name>.token-refresh-enabled", "true")
.config("spark.sql.catalog.<spark-catalog-name>.credential", "<client-id>:<client_secret>")
.config("spark.sql.catalog.<spark-catalog-name>.warehouse", <polaris_catalog_name>)
.config("spark.sql.catalog.polaris.scope", 'PRINCIPAL_ROLE:ALL')
.config("spark.sql.catalog.polaris.header.X-Iceberg-Access-Delegation", 'vended-credentials')
.getOrCreate()
```
Similar as the CLI command, make sure the corresponding fields are replaced correctly.

### Create tables with Spark
After the spark is started, you can use it to create and access Iceberg and Delta table like what you are doing before,
for example:
```python
spark.sql("USE polaris")
spark.sql("CREATE NAMESPACE IF NOT EXISTS DELTA_NS")
spark.sql("CREATE NAMESPACE IF NOT EXISTS DELTA_NS.PUBLIC")
spark.sql("USE NAMESPACE DELTA_NS.PUBLIC")
spark.sql("""CREATE TABLE IF NOT EXISTS PEOPLE (
id int, name string)
USING delta LOCATION 'file:///tmp/delta_tables/people';

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

In general, we've switched to using "/var/tmp/" instead of "/tmp/" in Getting Started due to tmp dir's GC sometimes being quick to dump

""")
```

## Limitations
The Polaris Spark client has the following functionality limitations:
1) Create table as select (CTAS) is not supported for Delta tables. As a result, the `saveAsTable` method of `Dataframe`
is also not supported, since it relies on the CTAS support.
2) Create a Delta table without explicit location is not supported.
3) Rename a Delta table is not supported.
4) ALTER TABLE ... SET LOCATION/SET FILEFORMAT/ADD PARTITION is not supported for DELTA table.
5) For other non-Iceberg tables like csv, there is no specific guarantee provided today.
6) TABLE_WRITE_DATA privileges is not supported for Delta Table.
7) Credential Vending is not supported for Delta Table.