Class ApproximateMemoryUsage

Namespace

RocksDbNet

Assembly

RocksDb.Net.dll

How much memory a set of databases and caches is using, at one moment.

public sealed class ApproximateMemoryUsage : RocksDbHandle, IDisposable

Inheritance

object

RocksDbHandle

ApproximateMemoryUsage

Implements

IDisposable

Inherited Members

RocksDbHandle.Handle

RocksDbHandle.Owned

RocksDbHandle.IsDisposed

RocksDbHandle.ThrowIfDisposed()

RocksDbHandle.Dispose()

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

A snapshot, not a live view: each figure is read once when this is created and does not move afterwards. Take another to see a change.

What this adds, and what it does not. Every individual figure below is already reachable without it — Usage for a cache, rocksdb.cur-size-all-mem-tables and rocksdb.estimate-table-readers-mem through GetAggregatedPropertyInt(string) for a database. What is new is the aggregation: one snapshot spanning several databases and several caches, which otherwise means writing the loop and knowing which properties to sum. If you are asking about one database, the properties are the simpler answer and this is not worth reaching for.

Properties

CacheTotal

Bytes held by the caches that were added.

public ulong CacheTotal { get; }

Property Value

ulong

MemTableReadersTotal

Bytes held by table readers: index and filter blocks, mainly.

public ulong MemTableReadersTotal { get; }

Property Value

ulong

MemTableTotal

Bytes held by memtables, flushed and unflushed.

public ulong MemTableTotal { get; }

Property Value

ulong

MemTableUnflushed

Bytes held by memtables whose contents are not yet in an SST file.

public ulong MemTableUnflushed { get; }

Property Value

ulong

Remarks

The part of MemTableTotal that a flush would release.

Methods

DisposeHandle()

Releases the native handle. Called during disposal.

protected override void DisposeHandle()

Remarks

Protected rather than public: it destroys the native object without marking this instance disposed or clearing the handle, so calling it from outside and then disposing normally would free the same pointer twice. It was the most Dispose-looking member on the type. Callers want Dispose().

Take(MemoryConsumers)

Takes a snapshot over consumers.

public static ApproximateMemoryUsage Take(MemoryConsumers consumers)

Parameters

consumers MemoryConsumers

Returns

ApproximateMemoryUsage

Remarks

The consumers may be disposed once this returns: the figures are read here, not later.