org.elasticsearch.index

Class MergeSchedulerConfig

java.lang.Object

org.elasticsearch.index.MergeSchedulerConfig

public final class MergeSchedulerConfig
extends java.lang.Object

The merge scheduler (ConcurrentMergeScheduler) controls the execution of merge operations once they are needed (according to the merge policy). Merges run in separate threads, and when the maximum number of threads is reached, further merges will wait until a merge thread becomes available.

The merge scheduler supports the following dynamic settings:

• index.merge.scheduler.max_thread_count: The maximum number of threads that may be merging at once. Defaults to Math.max(1, Math.min(4, Runtime.getRuntime().availableProcessors() / 2)) which works well for a good solid-state-disk (SSD). If your index is on spinning platter drives instead, decrease this to 1.
• index.merge.scheduler.auto_throttle: If this is true (the default), then the merge scheduler will rate-limit IO (writes) for merges to an adaptive value depending on how many merges are requested over time. An application with a low indexing rate that unluckily suddenly requires a large merge will see that merge aggressively throttled, while an application doing heavy indexing will see the throttle move higher to allow merges to keep up with ongoing indexing.

Field Summary

Fields

Modifier and Type	Field and Description
static Setting<java.lang.Boolean>	AUTO_THROTTLE_SETTING
static Setting<java.lang.Integer>	MAX_MERGE_COUNT_SETTING
static Setting<java.lang.Integer>	MAX_THREAD_COUNT_SETTING

Method Summary

Modifier and Type	Method and Description
int	getMaxMergeCount() Returns maxMergeCount.
int	getMaxThreadCount() Returns maxThreadCount.
boolean	isAutoThrottle() Returns true iff auto throttle is enabled.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_THREAD_COUNT_SETTING

public static final Setting<java.lang.Integer> MAX_THREAD_COUNT_SETTING

MAX_MERGE_COUNT_SETTING

public static final Setting<java.lang.Integer> MAX_MERGE_COUNT_SETTING

AUTO_THROTTLE_SETTING

public static final Setting<java.lang.Boolean> AUTO_THROTTLE_SETTING

Method Detail

isAutoThrottle

public boolean isAutoThrottle()

Returns true iff auto throttle is enabled.

See Also:

ConcurrentMergeScheduler.enableAutoIOThrottle()

getMaxThreadCount

public int getMaxThreadCount()

Returns maxThreadCount.

getMaxMergeCount

public int getMaxMergeCount()

Returns maxMergeCount.