Housekeeping

This is the manual for older MicroStream versions (Version < 5.0).

The new documentation (Version >= 5.0) is located at:

https://docs.microstream.one/

Intervall and Time Budget

Housekeeping interval and time budget is configured by setting up a StorageHousekeepingController.

Available properties are:

• House keeping interval interval the housekeeping is triggered in milliseconds, default once per every second

• House keeping budget time budget for housekeeping in nanoseconds, default is 0.01 seconds

EmbeddedStorageManager storage = EmbeddedStorage.Foundation(
	Storage.ConfigurationBuilder()
		.setHousekeepingController(Storage.HousekeepingController(1000, 10_000_000))
		.createConfiguration())
	.start();

File Sizes and Payload

The desired file min and max sizes and payload ratio is configured by the StorageDataFileEvaluator:

available properties are:

• Data file minimum size Files smaller then minimum file size will be merged with other files if possible, default is 1 MB.
• Data file maximum size Files larger then maximum file size will be split in smaller ones, default is 8 MB.
• Data file minimum use ratio Ratio of non-gap data contained in a storage file to prevent the file from being dissolved, default is 0.75 (75%).

EmbeddedStorageManager storage = EmbeddedStorage.Foundation(
	Storage.ConfigurationBuilder()
		.setDataFileEvaluator(Storage.DataFileEvaluator(1024*1024, 1024*1024*8, 0.75))
		.createConfiguration())
	.start();

Cache

The lifetime of objects in the internal entity cache can be configured by the StorageEntityCacheEvaluator:

Available properties are:

• Entity cache threshold

  Abstract threshold value, roughly comparable to size in bytes with a time component, at which a cache must be cleared of some entities. Default is 1000000000.

• Entity cache timeout Time in milliseconds after that an entity is considered to be old if not read meanwhile. must be greater zero, default is 86400000ms (1 day).

EmbeddedStorageManager storage = EmbeddedStorage.Foundation(
	Storage.ConfigurationBuilder()
		.setEntityCacheEvaluator(Storage.EntityCacheEvaluator(
			86_400_000, 
			1_000_000_000))
		.createConfiguration())
	.start();

For external configuration see: Properties