Configuring Spark Dynamic Resource Scheduling in YARN Mode

Scenario

Resources are a key factor that affects Spark execution efficiency. Allocating multiple executors to a long-running service, such as the JDBCServer, without tasks can result in improper scheduling and wasted resources if there are insufficient resources available for other applications.

Dynamic resource scheduling can add or remove executors of applications in real time based on the task load. In this way, resources are dynamically scheduled to applications.

Procedure

Configure the external shuffle service.
Log in to FusionInsight Manager, choose Cluster > Services > Spark2x, click Configurations, and click All Configurations. Enter the spark.dynamicAllocation.enabled parameter name in the search box and set it to true to enable dynamic resource scheduling.

Table 1 lists some optional configuration items.

**Table 1** Parameters for dynamic resource scheduling
Configuration Item	Description	Default Value
spark.dynamicAllocation.minExecutors	Indicates the minimum number of executors.	0
spark.dynamicAllocation.initialExecutors	Indicates the number of initial executors.	0
spark.dynamicAllocation.maxExecutors	Indicates the maximum number of executors.	2048
spark.dynamicAllocation.schedulerBacklogTimeout	Indicates the first timeout period for scheduling.	1s
spark.dynamicAllocation.sustainedSchedulerBacklogTimeout	Indicates the second and later timeout interval for scheduling.	1s
spark.dynamicAllocation.executorIdleTimeout	Indicates the idle timeout interval for common executors.	60s
spark.dynamicAllocation.cachedExecutorIdleTimeout	Indicates the idle timeout interval for executors with cached blocks.	JDBCServer2x: 2147483647s IndexServer2x: 2147483647s SparkResource2x: 120