runtime/me.ahoo.wow.runtime/StateCacheSizing

StateCacheSizing

How much each context's state cache keeps when the host does not bound it by a number of states (wow.state-cache.capacity): a HEAP_SHARE of the JVM's maximum heap, split between the node's contexts, in the estimated bytes of the states it holds. A cached state is the aggregate's state object with its metadata, estimated at CachedState.STATE_BYTES, and its recent requests, whose rings grow with the requests the aggregate committed: most aggregates commit few, so the bytes hold far more of them than a count sized for full rings would. A domain whose states are much larger than the estimate sets the capacity itself.

The budget is at least MIN states with full rings, the former fixed default.

Properties

HEAP_SHARE

const val HEAP_SHARE: Double = 0.1

The share of the maximum heap the state caches of a node take together.

MIN

const val MIN: Int

The fewest states with full rings a context's cache holds when bounded by bytes.

Functions

entryBytes

fun entryBytes(recentRequests: Int): Long

The estimated bytes of one cached state whose rings hold recentRequests requests.

maxBytes

fun maxBytes(contexts: Int, recentRequests: Int, maxHeap: Long = Runtime.getRuntime().maxMemory()): Long

The estimated bytes each of contexts state caches holds on a heap of at most maxHeap bytes, each state keeping up to recentRequests recent requests.