Improvement

This improvement enables collection of some PolyBase-specific Xevents in SQL Server 2019

More Information

Due to PolyBase being implemented by external services (PolyBase Engine and PolyBase Data Movement), the Xevents capture cannot be enabled in the same way that other SQL Server Engine Xevents are enabled (e.g. T-SQL commands or SQL Server Management Studio GUI).

  • To enable PolyBase Xevents collection, you need to create a new file EngineService.xevents.xml that contains the following:

<event_sessions>   <event_session     name="DMSCommonSession" maxMemory="2" allowRecursiveEvents="true" eventRetentionMode="noEventLoss"     trackCausality="false" dispatchLatency="5" maxEventSize="1"     memoryPartitionMode="none"> 

<!-- these events are available on all SQL Server platforms (Windows/Linux/Big Data Clusters) -->     <event package="DMSCommonXEvents" name="dsql_plan" />     <event package="DMSCommonXEvents" name="name_node_ha" />     <event package="DMSCommonXEvents" name="polybase_authorize_begin" />     <event package="DMSCommonXEvents" name="polybase_authorize_end" />   <!-- these events are only available for SQL Server Big Data Clusters -->     <event package="DMSCommonXEvents" name="build_openrowset_query" />     <event package="DMSCommonXEvents" name="initialize_metadata_processor" />

    <target package="package0" name="event_file">       <parameter name="filename" value="PdwXevents.xel" />       <parameter name="max_file_size" value="10" />       <parameter name="max_rollover_files" value="10" />     </target>     </event_session> </event_sessions>

  • Save the file to the ..\MSSQL\Binn\Polybase folder. You may have to save it to a different location and then move the file to this folder.

  • Restart PolyBase Engine service and you will see the file PdwXevents_0_{####}.xel created in the ..\MSSQL\Log\Polybase folder. You can view this XEL file in the same way as any other XEvents XEL file capture.

Event Descriptions

Xevent

Fields

Event/Field Description

Available on all platforms

 

 

dsql_plan

Dsql plan information

memo_xml

Memo xml

dsql_plan_xml

XML of dsql plan

showplan_xml

Showplan xml format of dsql plan.

distributed_query_hash

Query Hash is unique for same query and will be used to identify query regression

distributed_statement_id

Statement ID is unique for each statement in a batch and can be used for statement level correlation

distributed_request_id

Request ID is unique for each sp_execute_memo and can be used for correlation of sp_execute_memo execution

distributed_query_id

Query ID

distributed_plan_step

Step in a distributed query plan

dms_plan_step

Step in a DMS plan

sql_handle

SQL Handle

name_node_ha

NameNode ha tracing information.

uri

NameNode URI

retry_count

Number of retry count for this node.

isActiveNamenode

shouldRetry

polybase_authorize_begin

PolyBase authorize begin event

app_name

Application name

session_id

Session ID

polybase_authorize_end

PolyBase authorize end event

app_name

Application name

session_id

Session ID

Available on BDC

build_openrowset_query

Build storagepool select from openrowset query

select_query

The select from openrowset query

distributed_query_hash

Query Hash is unique for same query and will be used to identify query regression

distributed_statement_id

Statement ID is unique for each statement in a batch and can be used for statement level correlation

distributed_request_id

Request ID is unique for each sp_execute_memo and can be used for correlation of sp_execute_memo execution

distributed_query_id

Query ID

distributed_plan_step

Step in a distributed query plan

dms_plan_step

Step in a DMS plan

sql_handle

SQL Handle

initialize_metadata_processor

Metadata processor is initialized

shards_list

List of shard endpoints

Resolution

This improvement is included in the following cumulative update for SQL Server:

About cumulative updates for SQL Server:

Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:

References

Learn about the terminology that Microsoft uses to describe software updates.

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