layout	title	nav_order	parent
page	Gluten with Velox Backend	1	Getting-Started

Supported Version

Type	Version
Spark	3.2.2, 3.3.1, 3.4.3, 3.5.1
OS	Ubuntu20.04/22.04, Centos7/8
jdk	openjdk8/jdk17
scala	2.12

Prerequisite

Currently, Gluten+Velox backend is only tested on Ubuntu20.04/Ubuntu22.04/Centos7/Centos8. Other kinds of OS support are still in progress. The long term goal is to support several common OS and conda env deployment.

Currently, the officially supported Spark versions are 3.2.2, 3.3.1, 3.4.3 and 3.5.1.

We need to set up the JAVA_HOME env. Currently, Gluten supports java 8 and java 17.

For x86_64

## make sure jdk8 is used
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
export PATH=$JAVA_HOME/bin:$PATH

For aarch64

## make sure jdk8 is used
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-arm64
export PATH=$JAVA_HOME/bin:$PATH

Get gluten

## config maven, like proxy in ~/.m2/settings.xml

## fetch gluten code
git clone https://github.com/apache/incubator-gluten.git

Build Gluten with Velox Backend

It's recommended to use buildbundle-veloxbe.sh to build gluten in one script. Gluten build guide listed the parameters and their default value of build command for your reference.

For x86_64 build

First time build for all supported spark versions.

./dev/buildbundle-veloxbe.sh

After a complete build, if only some gluten code is changed, you can use the following command to skip building velox/arrow and setting up build dependencies.

./dev/buildbundle-veloxbe.sh --enable_ep_cache=ON --build_arrow=OFF --run_setup_script=OFF

For aarch64 build:

export CPU_TARGET="aarch64"

./dev/builddeps-veloxbe.sh

Build Velox separately

Currently, Gluten is using a forked Velox which is daily updated based on upstream Velox.

Scripts under /path/to/gluten/ep/build-velox/src provide get_velox.sh and build_velox.sh to build Velox separately, you could use these scripts with custom repo/branch/location.

Velox provides arrow/parquet lib. Gluten cpp module need a required VELOX_HOME parsed by --velox_home, if you specify custom ep location, make sure these variables be passed correctly.

## fetch Velox and compile
./dev/builddeps-veloxbe.sh build_velox

## compile Gluten cpp module
./dev/builddeps-veloxbe.sh build_gluten_cpp

## compile Gluten java module and create package jar
cd /path/to/gluten
# For spark3.2.x
mvn clean package -Pbackends-velox -Pceleborn -Puniffle -Pspark-3.2 -DskipTests
# For spark3.3.x
mvn clean package -Pbackends-velox -Pceleborn -Puniffle -Pspark-3.3 -DskipTests
# For spark3.4.x
mvn clean package -Pbackends-velox -Pceleborn -Puniffle -Pspark-3.4 -DskipTests
# For spark3.5.x
mvn clean package -Pbackends-velox -Pceleborn -Puniffle -Pspark-3.5 -DskipTests

Notes： Building Velox may fail caused by oom. You can prevent this failure by adjusting NUM_THREADS (e.g., export NUM_THREADS=4) before building Gluten/Velox.

Once building successfully, the Jar file will be generated in the directory: package/target/<gluten-jar> for Spark 3.2.x/Spark 3.3.x/Spark 3.4.x/Spark 3.5.x.

Dependency library deployment

With config enable_vcpkg=ON, the dependency libraries will be built and statically linked into libvelox.so and libgluten.so, which is packed into the gluten-jar. In this way, only the gluten-jar is needed to add to spark.<driver|executor>.extraClassPath and spark will deploy the jar to each worker node. It's better to build the static version using a clean docker image without any extra libraries installed. On host with some libraries like jemalloc installed, the script may crash with odd message. You may need to uninstall those libraries to get a clean host.

With config enable_vcpkg=OFF, not all dependency libraries will be statically linked, instead the script will install the libraries to system then pack the dependency libraries into another jar named gluten-package-${Maven-artifact-version}.jar. Then you need to add the jar to extraClassPath and set spark.gluten.loadLibFromJar=true. Otherwise, you need to install shared dependency libraries on each worker node. You may find the libraries list from the gluten-package jar.

HDFS support

Hadoop hdfs support is ready via the libhdfs3 library. The libhdfs3 provides native API for Hadoop I/O without the drawbacks of JNI. It also provides advanced authentication like Kerberos based. Please note this library has several dependencies which may require extra installations on Driver and Worker node.

Build with HDFS support

To build Gluten with HDFS support, below command is suggested:

cd /path/to/gluten
./dev/buildbundle-veloxbe.sh --enable_hdfs=ON

Configuration about HDFS support

HDFS uris (hdfs://host:port) will be extracted from a valid hdfs file path to initialize hdfs client, you do not need to specify it explicitly.

libhdfs3 need a configuration file and example here, this file is a bit different from hdfs-site.xml and core-site.xml. Download that example config file to local and do some needed modifications to support HA or else, then set env variable like below to use it, or upload it to HDFS to use, more details here.

// Spark local mode
export LIBHDFS3_CONF="/path/to/hdfs-client.xml"

// Spark Yarn cluster mode
--conf spark.executorEnv.LIBHDFS3_CONF="/path/to/hdfs-client.xml"

// Spark Yarn cluster mode and upload hdfs config file
cp /path/to/hdfs-client.xml hdfs-client.xml
--files hdfs-client.xml

One typical deployment on Spark/HDFS cluster is to enable short-circuit reading. Short-circuit reads provide a substantial performance boost to many applications.

By default libhdfs3 does not set the default hdfs domain socket path to support HDFS short-circuit read. If this feature is required in HDFS setup, users may need to setup the domain socket path correctly by patching the libhdfs3 source code or by setting the correct config environment. In Gluten the short-circuit domain socket path is set to "/var/lib/hadoop-hdfs/dn_socket" in build_velox.sh So we need to make sure the folder existed and user has write access as below script.

sudo mkdir -p /var/lib/hadoop-hdfs/
sudo chown <sparkuser>:<sparkuser> /var/lib/hadoop-hdfs/

You also need to add configuration to the "hdfs-site.xml" as below:

<property>
  <name>dfs.client.read.shortcircuit</name>
  <value>true</value>
</property>
<property>
  <name>dfs.domain.socket.path</name>
  <value>/var/lib/hadoop-hdfs/dn_socket</value>
</property>

Kerberos support

Here are two steps to enable kerberos.

Make sure the hdfs-client.xml contains

<property>
  <name>hadoop.security.authentication</name>
  <value>kerberos</value>
</property>

Specify the environment variable KRB5CCNAME and upload the kerberos ticket cache file

--conf spark.executorEnv.KRB5CCNAME=krb5cc_0000  --files /tmp/krb5cc_0000

The ticket cache file can be found by klist.

Azure Blob File System (ABFS) support

Velox supports ABFS with the open source Azure SDK for C++ and Gluten uses the Velox ABFS connector to connect with ABFS. The build option for ABFS (enable_abfs) must be set to enable this feature as listed below.

cd /path/to/gluten
./dev/buildbundle-veloxbe.sh --enable_abfs=ON

Please refer Velox ABFS part for more detailed configurations.

AWS S3 support

Velox supports S3 with the open source AWS C++ SDK and Gluten uses Velox S3 connector to connect with S3. A new build option for S3(enable_s3) is added. Below command is used to enable this feature

cd /path/to/gluten
./dev/buildbundle-veloxbe.sh --enable_s3=ON

Currently there are several ways to asscess S3 in Spark. Please refer Velox S3 part for more detailed configurations

Celeborn support

Gluten with velox backend supports Celeborn as remote shuffle service. Currently, the supported Celeborn versions are 0.3.x, 0.4.x and 0.5.x.

Below introduction is used to enable this feature.

First refer to this URL(https://github.com/apache/celeborn) to setup a celeborn cluster.

When compiling the Gluten Java module, it's required to enable celeborn profile, as follows:

mvn clean package -Pbackends-velox -Pspark-3.3 -Pceleborn -DskipTests

Then add the Gluten and Spark Celeborn Client packages to your Spark application's classpath(usually add them into $SPARK_HOME/jars).

Celeborn: celeborn-client-spark-3-shaded_2.12-[celebornVersion].jar
Gluten: gluten-velox-bundle-spark3.x_2.12-xx_xx_xx-SNAPSHOT.jar (The bundled Gluten Jar. Make sure -Pceleborn is specified when it is built.)

Currently to use Gluten following configurations are required in spark-defaults.conf

spark.shuffle.manager org.apache.spark.shuffle.gluten.celeborn.CelebornShuffleManager

# celeborn master
spark.celeborn.master.endpoints clb-master:9097

spark.shuffle.service.enabled false

# options: hash, sort
# Hash shuffle writer use (partition count) * (celeborn.push.buffer.max.size) * (spark.executor.cores) memory.
# Sort shuffle writer uses less memory than hash shuffle writer, if your shuffle partition count is large, try to use sort hash writer.  
spark.celeborn.client.spark.shuffle.writer hash

# We recommend setting spark.celeborn.client.push.replicate.enabled to true to enable server-side data replication
# If you have only one worker, this setting must be false 
# If your Celeborn is using HDFS, it's recommended to set this setting to false
spark.celeborn.client.push.replicate.enabled true

# Support for Spark AQE only tested under Spark 3
# we recommend setting localShuffleReader to false to get better performance of Celeborn
spark.sql.adaptive.localShuffleReader.enabled false

# If Celeborn is using HDFS
spark.celeborn.storage.hdfs.dir hdfs://<namenode>/celeborn

# If you want to use dynamic resource allocation,
# please refer to this URL (https://github.com/apache/celeborn/tree/main/assets/spark-patch) to apply the patch into your own Spark.
spark.dynamicAllocation.enabled false

Uniffle support

Uniffle with velox backend supports Uniffle as remote shuffle service. Currently, the supported Uniffle versions are 0.9.0.

First refer to this URL(https://uniffle.apache.org/docs/intro) to get start with uniffle.

When compiling the Gluten Java module, it's required to enable uniffle profile, as follows:

mvn clean package -Pbackends-velox -Pspark-3.3 -Puniffle -DskipTests

Then add the Uniffle and Spark Celeborn Client packages to your Spark application's classpath(usually add them into $SPARK_HOME/jars).

Uniffle: rss-client-spark3-shaded-[uniffleVersion].jar
Gluten: gluten-velox-bundle-spark3.x_2.12-xx_xx_xx-SNAPSHOT.jar (The bundled Gluten Jar. Make sure -Puniffle is specified when it is built.)

Currently to use Gluten following configurations are required in spark-defaults.conf

spark.shuffle.manager org.apache.spark.shuffle.gluten.uniffle.UniffleShuffleManager

# uniffle coordinator address
spark.rss.coordinator.quorum ip:port

# Support for Spark AQE
spark.sql.adaptive.localShuffleReader.enabled false
spark.shuffle.service.enabled false

# Uniffle support mutilple storage types, you can choose one of them.
# Such as MEMORY,LOCALFILE,MEMORY_LOCALFILE,HDFS,MEMORY_HDFS,LOCALFILE_HDFS,MEMORY_LOCALFILE_HDFS
spark.rss.storage.type LOCALFILE_HDFS

# If you want to use dynamic resource allocation,
# please refer to this URL (https://uniffle.apache.org/docs/client-guide#support-spark-dynamic-allocation) for more details.
spark.dynamicAllocation.enabled false

DeltaLake Support

Gluten with velox backend supports DeltaLake table.

How to use

First of all, compile gluten-delta module by a delta profile, as follows:

mvn clean package -Pbackends-velox -Pspark-3.3 -Pdelta -DskipTests

Once built successfully, delta features will be included in gluten-velox-bundle-X jar. Then you can query delta table by gluten/velox without scan's fallback.

Gluten with velox backends also support the column mapping of delta tables. About column mapping, see more here.

Iceberg Support

Gluten with velox backend supports Iceberg table. Currently, both reading COW (Copy-On-Write) and MOR (Merge-On-Read) tables are supported.

How to use

First of all, compile gluten-iceberg module by a iceberg profile, as follows:

mvn clean package -Pbackends-velox -Pspark-3.3 -Piceberg -DskipTests

Once built successfully, iceberg features will be included in gluten-velox-bundle-X jar. Then you can query iceberg table by gluten/velox without scan's fallback.

Hudi Support

Gluten with velox backend supports Hudi table. Currently, only reading COW (Copy-On-Write) tables is supported.

How to use

First of all, compile gluten-hudi module by a hudi profile, as follows:

mvn clean package -Pbackends-velox -Pspark-3.3 -Phudi -DskipTests

Once built successfully, hudi features will be included in gluten-velox-bundle-X jar. Then you can query hudi COW table by gluten/velox without scan's fallback.

Coverage

Spark3.3 has 387 functions in total. ~240 are commonly used. To get the support status of all Spark built-in functions, please refer to Velox Backend's Supported Operators & Functions.

Velox doesn't support ANSI mode), so as Gluten. Once ANSI mode is enabled in Spark config, Gluten will fallback to Vanilla Spark.

To identify what can be offloaded in a query and detailed fallback reasons, user can follow below steps to retrieve corresponding logs.

1) Enable Gluten by proper [configuration](https://github.com/apache/incubator-gluten/blob/main/docs/Configuration.md).

2) Disable Spark AQE to trigger plan validation in Gluten
spark.sql.adaptive.enabled = false

3) Check physical plan 
sparkSession.sql("your_sql").explain()

With above steps, you will get a physical plan output like:

== Physical Plan ==
-Execute InsertIntoHiveTable (7)
  +- Coalesce (6)
    +- VeloxColumnarToRowExec (5)
      +- ^ ProjectExecTransformer (3)
        +- GlutenRowToArrowColumnar (2)
          +- Scan hive default.extracted_db_pins (1)

GlutenRowToArrowColumnar/VeloxColumnarToRowExec indicates there is a fallback operator before or after it. And you may find fallback reason like below in logs.

native validation failed due to: in ProjectRel, Scalar function name not registered: get_struct_field, called with arguments: (ROW<col_0:INTEGER,col_1:BIGINT,col_2:BIGINT>, INTEGER).

In the above, the symbol ^ indicates a plan is offloaded to Velox in a stage. In Spark DAG, all such pipelined plans (consecutive plans marked with ^) are plotted inside an umbrella node named WholeStageCodegenTransformer (It's not codegen node. The naming is just for making it well plotted like Spark Whole Stage Codegen).

Spill (Experimental)

Velox backend supports spilling-to-disk.

Using the following configuration options to customize spilling:

Name	Default Value	Description
spark.gluten.sql.columnar.backend.velox.spillStrategy	auto	none: Disable spill on Velox backend; auto: Let Spark memory manager manage Velox's spilling
spark.gluten.sql.columnar.backend.velox.spillFileSystem	local	The filesystem used to store spill data. local: The local file system. heap-over-local: Write files to JVM heap if having extra heap space. Otherwise write to local file system.
spark.gluten.sql.columnar.backend.velox.aggregationSpillEnabled	true	Whether spill is enabled on aggregations
spark.gluten.sql.columnar.backend.velox.joinSpillEnabled	true	Whether spill is enabled on joins
spark.gluten.sql.columnar.backend.velox.orderBySpillEnabled	true	Whether spill is enabled on sorts
spark.gluten.sql.columnar.backend.velox.maxSpillLevel	4	The max allowed spilling level with zero being the initial spilling level
spark.gluten.sql.columnar.backend.velox.maxSpillFileSize	1GB	The max allowed spill file size. If it is zero, then there is no limit
spark.gluten.sql.columnar.backend.velox.spillStartPartitionBit	29	The start partition bit which is used with 'spillPartitionBits' together to calculate the spilling partition number
spark.gluten.sql.columnar.backend.velox.spillPartitionBits	2	The number of bits used to calculate the spilling partition number. The number of spilling partitions will be power of two
spark.gluten.sql.columnar.backend.velox.spillableReservationGrowthPct	25	The spillable memory reservation growth percentage of the previous memory reservation size
spark.gluten.sql.columnar.backend.velox.spillThreadNum	0	(Experimental) The thread num of a dedicated thread pool to do spill

Velox User-Defined Functions (UDF) and User-Defined Aggregate Functions (UDAF)

Please check the VeloxNativeUDF.md for more detailed usage and configurations.

High-Bandwidth Memory (HBM) support

Gluten supports allocating memory on HBM. This feature is optional and is disabled by default. It is implemented on top of Memkind library. You can refer to memkind's readme for more details.

Build Gluten with HBM

Gluten will internally build and link to a specific version of Memkind library and hwloc. Other dependencies should be installed on Driver and Worker node first:

sudo apt install -y autoconf automake g++ libnuma-dev libtool numactl unzip libdaxctl-dev

After the set-up, you can now build Gluten with HBM. Below command is used to enable this feature

cd /path/to/gluten

## The script builds four jars for spark 3.2.2, 3.3.1, 3.4.3 and 3.5.1.
./dev/buildbundle-veloxbe.sh --enable_hbm=ON

Configure and enable HBM in Spark Application

At runtime, MEMKIND_HBW_NODES enviroment variable is detected for configuring HBM NUMA nodes. For the explaination to this variable, please refer to memkind's manual page. This can be set for all executors through spark conf, e.g. --conf spark.executorEnv.MEMKIND_HBW_NODES=8-15. Note that memory allocation fallback is also supported and cannot be turned off. If HBM is unavailable or fills up, the allocator will use default(DDR) memory.

Intel® QuickAssist Technology (QAT) support

Gluten supports using Intel® QuickAssist Technology (QAT) for data compression during Spark Shuffle. It benefits from QAT Hardware-based acceleration on compression/decompression, and uses Gzip as compression format for higher compression ratio to reduce the pressure on disks and network transmission.

This feature is based on QAT driver library and QATzip library. Please manually download QAT driver for your system, and follow its README to build and install on all Driver and Worker node: Intel® QuickAssist Technology Driver for Linux* – HW Version 2.0.

Software Requirements

Download QAT driver for your system, and follow its README to build and install on all Driver and Worker nodes: Intel® QuickAssist Technology Driver for Linux* – HW Version 2.0.
Below compression libraries need to be installed on all Driver and Worker nodes:
- Zlib* library of version 1.2.7 or higher
- ZSTD* library of version 1.5.4 or higher
- LZ4* library

Build Gluten with QAT

Setup ICP_ROOT environment variable to the directory where QAT driver is extracted. This environment variable is required during building Gluten and running Spark applications. It's recommended to put it in .bashrc on Driver and Worker nodes.

echo "export ICP_ROOT=/path/to/QAT_driver" >> ~/.bashrc
source ~/.bashrc

# Also set for root if running as non-root user
sudo su - 
echo "export ICP_ROOT=/path/to/QAT_driver" >> ~/.bashrc
exit

This step is required if your application is running as Non-root user. The users must be added to the 'qat' group after QAT drvier is installed. And change the amount of max locked memory for the username that is included in the group name. This can be done by specifying the limit in /etc/security/limits.conf.

sudo su -
usermod -aG qat username # need relogin to take effect

# To set 500MB add a line like this in /etc/security/limits.conf
echo "@qat - memlock 500000" >> /etc/security/limits.conf

exit

Enable huge page. This step is required to execute each time after system reboot. We recommend using systemctl to manage at system startup. You change the values for "max_huge_pages" and "max_huge_pages_per_process" to make sure there are enough resources for your workload. As for Spark applications, one process matches one executor. Within the executor, every task is allocated a maximum of 5 huge pages.

sudo su -

cat << EOF > /usr/local/bin/qat_startup.sh
#!/bin/bash
echo 1024 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
rmmod usdm_drv
insmod $ICP_ROOT/build/usdm_drv.ko max_huge_pages=1024 max_huge_pages_per_process=32
EOF

chmod +x /usr/local/bin/qat_startup.sh

cat << EOF > /etc/systemd/system/qat_startup.service
[Unit]
Description=Configure QAT

[Service]
ExecStart=/usr/local/bin/qat_startup.sh

[Install]
WantedBy=multi-user.target
EOF

systemctl enable qat_startup.service
systemctl start qat_startup.service # setup immediately
systemctl status qat_startup.service

exit

After the setup, you are now ready to build Gluten with QAT. Use the command below to enable this feature:

cd /path/to/gluten

## The script builds four jars for spark 3.2.2, 3.3.1, 3.4.3 and 3.5.1.
./dev/buildbundle-veloxbe.sh --enable_qat=ON

Enable QAT with Gzip/Zstd for shuffle compression

To offload shuffle compression into QAT, first make sure you have the right QAT configuration file at /etc/4xxx_devX.conf. We provide a example configuration file. This configuration sets up to 4 processes that can bind to 1 QAT, and each process can use up to 16 QAT DC instances.

## run as root
## Overwrite QAT configuration file.
cd /etc
for i in {0..7}; do echo "4xxx_dev$i.conf"; done | xargs -i cp -f /path/to/gluten/docs/qat/4x16.conf {}
## Restart QAT after updating configuration files.
adf_ctl restart

Check QAT status and make sure the status is up

adf_ctl status

The output should be like:

Checking status of all devices.
There is 8 QAT acceleration device(s) in the system:
 qat_dev0 - type: 4xxx,  inst_id: 0,  node_id: 0,  bsf: 0000:6b:00.0,  #accel: 1 #engines: 9 state: up
 qat_dev1 - type: 4xxx,  inst_id: 1,  node_id: 1,  bsf: 0000:70:00.0,  #accel: 1 #engines: 9 state: up
 qat_dev2 - type: 4xxx,  inst_id: 2,  node_id: 2,  bsf: 0000:75:00.0,  #accel: 1 #engines: 9 state: up
 qat_dev3 - type: 4xxx,  inst_id: 3,  node_id: 3,  bsf: 0000:7a:00.0,  #accel: 1 #engines: 9 state: up
 qat_dev4 - type: 4xxx,  inst_id: 4,  node_id: 4,  bsf: 0000:e8:00.0,  #accel: 1 #engines: 9 state: up
 qat_dev5 - type: 4xxx,  inst_id: 5,  node_id: 5,  bsf: 0000:ed:00.0,  #accel: 1 #engines: 9 state: up
 qat_dev6 - type: 4xxx,  inst_id: 6,  node_id: 6,  bsf: 0000:f2:00.0,  #accel: 1 #engines: 9 state: up
 qat_dev7 - type: 4xxx,  inst_id: 7,  node_id: 7,  bsf: 0000:f7:00.0,  #accel: 1 #engines: 9 state: up

Extra Gluten configurations are required when starting Spark application

--conf spark.gluten.sql.columnar.shuffle.codec=gzip # Valid options are gzip and zstd
--conf spark.gluten.sql.columnar.shuffle.codecBackend=qat

You can use below command to check whether QAT is working normally at run-time. The value of fw_counters should continue to increase during shuffle.

while :; do cat /sys/kernel/debug/qat_4xxx_0000:6b:00.0/fw_counters; sleep 1; done

QAT driver references

Documentation

README Text Files (README_QAT20.L.1.0.0-00021.txt)

Release Notes

Check out the Intel® QuickAssist Technology Software for Linux* - Release Notes for the latest changes in this release.

Getting Started Guide

Check out the Intel® QuickAssist Technology Software for Linux* - Getting Started Guide for detailed installation instructions.

Programmer's Guide

Check out the Intel® QuickAssist Technology Software for Linux* - Programmer's Guide for software usage guidelines.

For more Intel® QuickAssist Technology resources go to Intel® QuickAssist Technology (Intel® QAT)

Intel® In-memory Analytics Accelerator (IAA/IAX) support

Similar to Intel® QAT, Gluten supports using Intel® In-memory Analytics Accelerator (IAA, also called IAX) for data compression during Spark Shuffle. It benefits from IAA Hardware-based acceleration on compression/decompression, and uses Gzip as compression format for higher compression ratio to reduce the pressure on disks and network transmission.

This feature is based on Intel® QPL.

Build Gluten with IAA

Gluten will internally build and link to a specific version of QPL library, but extra environment setup is still required. Please refer to QPL Installation Guide to install dependencies and configure accelerators.

This step is required if your application is running as Non-root user. Create a group for the users who have privilege to use IAA, and grant group iaa read/write access to the IAA Work-Queues.

sudo groupadd iaa
sudo usermod -aG iaa username # need to relogin
sudo chgrp -R iaa /dev/iax
sudo chmod -R g+rw /dev/iax

After the set-up, you can now build Gluten with QAT. Below command is used to enable this feature

cd /path/to/gluten

## The script builds four jars for spark 3.2.2, 3.3.1, 3.4.3 and 3.5.1.
./dev/buildbundle-veloxbe.sh --enable_iaa=ON

Enable IAA with Gzip Compression for shuffle compression

To enable QAT at run-time, first make sure you have configured the IAA Work-Queues correctly, and the file permissions of /dev/iax/wqX.0 are correct.

sudo ls -l /dev/iax

The output should be like:

total 0
crw-rw---- 1 root iaa 509, 0 Apr  5 18:54 wq1.0
crw-rw---- 1 root iaa 509, 5 Apr  5 18:54 wq11.0
crw-rw---- 1 root iaa 509, 6 Apr  5 18:54 wq13.0
crw-rw---- 1 root iaa 509, 7 Apr  5 18:54 wq15.0
crw-rw---- 1 root iaa 509, 1 Apr  5 18:54 wq3.0
crw-rw---- 1 root iaa 509, 2 Apr  5 18:54 wq5.0
crw-rw---- 1 root iaa 509, 3 Apr  5 18:54 wq7.0
crw-rw---- 1 root iaa 509, 4 Apr  5 18:54 wq9.0

Extra Gluten configurations are required when starting Spark application

--conf spark.gluten.sql.columnar.shuffle.codec=gzip
--conf spark.gluten.sql.columnar.shuffle.codecBackend=iaa

IAA references

Intel® IAA Enabling Guide

Check out the Intel® In-Memory Analytics Accelerator (Intel® IAA) Enabling Guide

Intel® QPL Documentation

Check out the Intel® Query Processing Library (Intel® QPL) Documentation

Test TPC-H or TPC-DS on Gluten with Velox backend

All TPC-H and TPC-DS queries are supported in Gluten Velox backend.

Data preparation

The data generation scripts are TPC-H dategen script and TPC-DS dategen script.

The used TPC-H and TPC-DS queries are the original ones, and can be accessed from TPC-DS queries and TPC-H queries.

Some other versions of TPC-DS queries are also provided, but are not recommended for testing, including:

the modified TPC-DS queries with "Decimal-to-Double": TPC-DS non-decimal queries (outdated).

Submit the Spark SQL job

Submit test script from spark-shell. You can find the scala code to Run TPC-H as an example. Please remember to modify the location of TPC-H files as well as TPC-H queries before you run the testing.

var parquet_file_path = "/PATH/TO/TPCH_PARQUET_PATH"
var gluten_root = "/PATH/TO/GLUTEN"

Below script shows an example about how to run the testing, you should modify the parameters such as executor cores, memory, offHeap size based on your environment.

export GLUTEN_JAR = /PATH/TO/GLUTEN/package/target/<gluten-jar>
cat tpch_parquet.scala | spark-shell --name tpch_powertest_velox \
  --master yarn --deploy-mode client \
  --conf spark.plugins=org.apache.gluten.GlutenPlugin \
  --conf spark.driver.extraClassPath=${GLUTEN_JAR} \
  --conf spark.executor.extraClassPath=${GLUTEN_JAR} \
  --conf spark.memory.offHeap.enabled=true \
  --conf spark.memory.offHeap.size=20g \
  --conf spark.gluten.sql.columnar.forceShuffledHashJoin=true \
  --conf spark.shuffle.manager=org.apache.spark.shuffle.sort.ColumnarShuffleManager \
  --num-executors 6 \
  --executor-cores 6 \
  --driver-memory 20g \
  --executor-memory 25g \
  --conf spark.executor.memoryOverhead=5g \
  --conf spark.driver.maxResultSize=32g

Refer to Gluten configuration for more details.

Result

wholestagetransformer indicates that the offloading works.

Performance

Below table shows the TPC-H Q1 and Q6 Performance in a multiple-thread test (--num-executors 6 --executor-cores 6) for Velox and vanilla Spark. Both Parquet and ORC datasets are sf1024.

Query Performance (s)	Velox (ORC)	Vanilla Spark (Parquet)	Vanilla Spark (ORC)
TPC-H Q6	13.6	21.6	34.9
TPC-H Q1	26.1	76.7	84.9

External reference setup

TO ease your first-hand experience of using Gluten, we have set up an external reference cluster. If you are interested, please contact Weiting.Chen@intel.com.

Gluten UI

Gluten event

Gluten provides two events GlutenBuildInfoEvent and GlutenPlanFallbackEvent:

GlutenBuildInfoEvent, it contains the Gluten build information so that we are able to be aware of the environment when doing some debug. It includes Java Version, Scala Version, GCC Version, Gluten Version, Spark Version, Hadoop Version, Gluten Revision, Backend, Backend Revision, etc.
GlutenPlanFallbackEvent, it contains the fallback information for each query execution. Note, if the query execution is in AQE, then Gluten will post it for each stage.

Developers can register SparkListener to handle these two Gluten events.

SQL tab

Gluten provides a tab based on Spark UI, named Gluten SQL / DataFrame

This tab contains two parts:

The Gluten build information.
SQL/Dataframe queries fallback information.

If you want to disable Gluten UI, add a config when submitting --conf spark.gluten.ui.enabled=false.

History server

Gluten UI also supports Spark history server. Add gluten-ui jar into the history server classpath, e.g., $SPARK_HOME/jars, then restart history server.

Native plan string

Gluten supports inject native plan string into Spark explain with formatted mode by setting --conf spark.gluten.sql.injectNativePlanStringToExplain=true. Here is an example, how Gluten show the native plan string.

(9) WholeStageCodegenTransformer (2)
Input [6]: [c1#0L, c2#1L, c3#2L, c1#3L, c2#4L, c3#5L]
Arguments: false
Native Plan:
-- Project[expressions: (n3_6:BIGINT, "n0_0"), (n3_7:BIGINT, "n0_1"), (n3_8:BIGINT, "n0_2"), (n3_9:BIGINT, "n1_0"), (n3_10:BIGINT, "n1_1"), (n3_11:BIGINT, "n1_2")] -> n3_6:BIGINT, n3_7:BIGINT, n3_8:BIGINT, n3_9:BIGINT, n3_10:BIGINT, n3_11:BIGINT
  -- HashJoin[INNER n1_1=n0_1] -> n1_0:BIGINT, n1_1:BIGINT, n1_2:BIGINT, n0_0:BIGINT, n0_1:BIGINT, n0_2:BIGINT
    -- TableScan[table: hive_table, range filters: [(c2, Filter(IsNotNull, deterministic, null not allowed))]] -> n1_0:BIGINT, n1_1:BIGINT, n1_2:BIGINT
    -- ValueStream[] -> n0_0:BIGINT, n0_1:BIGINT, n0_2:BIGINT

Native plan with stats

Gluten supports print native plan with stats to executor system output stream by setting --conf spark.gluten.sql.debug=true. Note that, the plan string with stats is task level which may cause executor log size big. Here is an example, how Gluten show the native plan string with stats.

I20231121 10:19:42.348845 90094332 WholeStageResultIterator.cc:220] Native Plan with stats for: [Stage: 1 TID: 16]
-- Project[expressions: (n3_6:BIGINT, "n0_0"), (n3_7:BIGINT, "n0_1"), (n3_8:BIGINT, "n0_2"), (n3_9:BIGINT, "n1_0"), (n3_10:BIGINT, "n1_1"), (n3_11:BIGINT, "n1_2")] -> n3_6:BIGINT, n3_7:BIGINT, n3_8:BIGINT, n3_9:BIGINT, n3_10:BIGINT, n3_11:BIGINT
   Output: 27 rows (3.56KB, 3 batches), Cpu time: 10.58us, Blocked wall time: 0ns, Peak memory: 0B, Memory allocations: 0, Threads: 1
      queuedWallNanos              sum: 2.00us, count: 1, min: 2.00us, max: 2.00us
      runningAddInputWallNanos     sum: 626ns, count: 1, min: 626ns, max: 626ns
      runningFinishWallNanos       sum: 0ns, count: 1, min: 0ns, max: 0ns
      runningGetOutputWallNanos    sum: 5.54us, count: 1, min: 5.54us, max: 5.54us
  -- HashJoin[INNER n1_1=n0_1] -> n1_0:BIGINT, n1_1:BIGINT, n1_2:BIGINT, n0_0:BIGINT, n0_1:BIGINT, n0_2:BIGINT
     Output: 27 rows (3.56KB, 3 batches), Cpu time: 223.00us, Blocked wall time: 0ns, Peak memory: 93.12KB, Memory allocations: 15
     HashBuild: Input: 10 rows (960B, 10 batches), Output: 0 rows (0B, 0 batches), Cpu time: 185.67us, Blocked wall time: 0ns, Peak memory: 68.00KB, Memory allocations: 2, Threads: 1
        distinctKey0                 sum: 4, count: 1, min: 4, max: 4
        hashtable.capacity           sum: 4, count: 1, min: 4, max: 4
        hashtable.numDistinct        sum: 10, count: 1, min: 10, max: 10
        hashtable.numRehashes        sum: 1, count: 1, min: 1, max: 1
        queuedWallNanos              sum: 0ns, count: 1, min: 0ns, max: 0ns
        rangeKey0                    sum: 4, count: 1, min: 4, max: 4
        runningAddInputWallNanos     sum: 1.27ms, count: 1, min: 1.27ms, max: 1.27ms
        runningFinishWallNanos       sum: 0ns, count: 1, min: 0ns, max: 0ns
        runningGetOutputWallNanos    sum: 1.29us, count: 1, min: 1.29us, max: 1.29us
     H23/11/21 10:19:42 INFO TaskSetManager: Finished task 3.0 in stage 1.0 (TID 13) in 335 ms on 10.221.97.35 (executor driver) (1/10)
ashProbe: Input: 9 rows (864B, 3 batches), Output: 27 rows (3.56KB, 3 batches), Cpu time: 37.33us, Blocked wall time: 0ns, Peak memory: 25.12KB, Memory allocations: 13, Threads: 1
        dynamicFiltersProduced       sum: 1, count: 1, min: 1, max: 1
        queuedWallNanos              sum: 0ns, count: 1, min: 0ns, max: 0ns
        runningAddInputWallNanos     sum: 4.54us, count: 1, min: 4.54us, max: 4.54us
        runningFinishWallNanos       sum: 83ns, count: 1, min: 83ns, max: 83ns
        runningGetOutputWallNanos    sum: 29.08us, count: 1, min: 29.08us, max: 29.08us
    -- TableScan[table: hive_table, range filters: [(c2, Filter(IsNotNull, deterministic, null not allowed))]] -> n1_0:BIGINT, n1_1:BIGINT, n1_2:BIGINT
       Input: 9 rows (864B, 3 batches), Output: 9 rows (864B, 3 batches), Cpu time: 630.75us, Blocked wall time: 0ns, Peak memory: 2.44KB, Memory allocations: 63, Threads: 1, Splits: 3
          dataSourceWallNanos              sum: 102.00us, count: 1, min: 102.00us, max: 102.00us
          dynamicFiltersAccepted           sum: 1, count: 1, min: 1, max: 1
          flattenStringDictionaryValues    sum: 0, count: 1, min: 0, max: 0
          ioWaitNanos                      sum: 312.00us, count: 1, min: 312.00us, max: 312.00us
          localReadBytes                   sum: 0B, count: 1, min: 0B, max: 0B
          numLocalRead                     sum: 0, count: 1, min: 0, max: 0
          numPrefetch                      sum: 0, count: 1, min: 0, max: 0
          numRamRead                       sum: 0, count: 1, min: 0, max: 0
          numStorageRead                   sum: 6, count: 1, min: 6, max: 6
          overreadBytes                    sum: 0B, count: 1, min: 0B, max: 0B
          prefetchBytes                    sum: 0B, count: 1, min: 0B, max: 0B
          queryThreadIoLatency             sum: 12, count: 1, min: 12, max: 12
          ramReadBytes                     sum: 0B, count: 1, min: 0B, max: 0B
          runningAddInputWallNanos         sum: 0ns, count: 1, min: 0ns, max: 0ns
          runningFinishWallNanos           sum: 125ns, count: 1, min: 125ns, max: 125ns
          runningGetOutputWallNanos        sum: 1.07ms, count: 1, min: 1.07ms, max: 1.07ms
          skippedSplitBytes                sum: 0B, count: 1, min: 0B, max: 0B
          skippedSplits                    sum: 0, count: 1, min: 0, max: 0
          skippedStrides                   sum: 0, count: 1, min: 0, max: 0
          storageReadBytes                 sum: 3.44KB, count: 1, min: 3.44KB, max: 3.44KB
          totalScanTime                    sum: 0ns, count: 1, min: 0ns, max: 0ns
    -- ValueStream[] -> n0_0:BIGINT, n0_1:BIGINT, n0_2:BIGINT
       Input: 0 rows (0B, 0 batches), Output: 10 rows (960B, 10 batches), Cpu time: 1.03ms, Blocked wall time: 0ns, Peak memory: 0B, Memory allocations: 0, Threads: 1
          runningAddInputWallNanos     sum: 0ns, count: 1, min: 0ns, max: 0ns
          runningFinishWallNanos       sum: 54.62us, count: 1, min: 54.62us, max: 54.62us
          runningGetOutputWallNanos    sum: 1.10ms, count: 1, min: 1.10ms, max: 1.10ms

Gluten Implicits

Gluten provides a helper class to get the fallback summary from a Spark Dataset.

import org.apache.spark.sql.execution.GlutenImplicits._
val df = spark.sql("SELECT * FROM t")
df.fallbackSummary

Note that, if AQE is enabled, but the query is not materialized, then it will re-plan the query execution with disabled AQE. It is a workaround to get the final plan, and it may cause the inconsistent results with a materialized query. However, we have no choice.

Files

Velox.md

Latest commit

History

Velox.md

File metadata and controls

Supported Version

Prerequisite

Build Gluten with Velox Backend

Dependency library deployment

HDFS support

Build with HDFS support

Configuration about HDFS support

Kerberos support

Azure Blob File System (ABFS) support

AWS S3 support

Celeborn support

Uniffle support

DeltaLake Support

How to use

Iceberg Support

How to use

Hudi Support

How to use

Coverage

Spill (Experimental)

Velox User-Defined Functions (UDF) and User-Defined Aggregate Functions (UDAF)

High-Bandwidth Memory (HBM) support

Build Gluten with HBM

Configure and enable HBM in Spark Application

Intel® QuickAssist Technology (QAT) support

Software Requirements

Build Gluten with QAT

Enable QAT with Gzip/Zstd for shuffle compression

QAT driver references

Intel® In-memory Analytics Accelerator (IAA/IAX) support

Build Gluten with IAA

Enable IAA with Gzip Compression for shuffle compression

IAA references

Test TPC-H or TPC-DS on Gluten with Velox backend

Data preparation

Submit the Spark SQL job

Result

Performance

External reference setup

Gluten UI

Gluten event

SQL tab

History server

Native plan string

Native plan with stats

Gluten Implicits