public static long DefaultHeuristicPageCacheMemory()
{
// First check if we have a default override...
string defaultMemoryOverride = System.getProperty("dbms.pagecache.memory.default.override");
if (!string.ReferenceEquals(defaultMemoryOverride, null))
{
return(BYTES.apply(defaultMemoryOverride));
}
double ratioOfFreeMem = 0.50;
string defaultMemoryRatioOverride = System.getProperty("dbms.pagecache.memory.ratio.default.override");
if (!string.ReferenceEquals(defaultMemoryRatioOverride, null))
{
ratioOfFreeMem = double.Parse(defaultMemoryRatioOverride);
}
// Try to compute (RAM - maxheap) * 0.50 if we can get reliable numbers...
long maxHeapMemory = Runtime.Runtime.maxMemory();
if (0 < maxHeapMemory && maxHeapMemory < long.MaxValue)
{
try
{
long physicalMemory = OsBeanUtil.TotalPhysicalMemory;
if (0 < physicalMemory && physicalMemory < long.MaxValue && maxHeapMemory < physicalMemory)
{
long heuristic = ( long )((physicalMemory - maxHeapMemory) * ratioOfFreeMem);
long min = ByteUnit.mebiBytes(32); // We'd like at least 32 MiBs.
long max = Math.Min(maxHeapMemory * 70, ByteUnit.gibiBytes(20));
// Don't heuristically take more than 20 GiBs, and don't take more than 70 times our max heap.
// 20 GiBs of page cache memory is ~2.6 million 8 KiB pages. If each page has an overhead of
// 72 bytes, then this will take up ~175 MiBs of heap memory. We should be able to tolerate that
// in most environments. The "no more than 70 times heap" heuristic is based on the page size over
// the per page overhead, 8192 / 72 ~= 114, plus leaving some extra room on the heap for the rest
// of the system. This means that we won't heuristically try to create a page cache that is too
// large to fit on the heap.
return(Math.Min(max, Math.Max(min, heuristic)));
}
}
catch (Exception)
{
}
}
// ... otherwise we just go with 2 GiBs.
return(ByteUnit.gibiBytes(2));
}
//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @Test void veryLargePageListsMustBeFullyAccessible()
internal virtual void VeryLargePageListsMustBeFullyAccessible()
{
// We need roughly 2 GiBs of memory for the meta-data here, which is why this is an IT and not a Test.
// We add one extra page worth of data to the size here, to avoid ending up on a "convenient" boundary.
int pageSize = ( int )ByteUnit.kibiBytes(8);
long pageCacheSize = ByteUnit.gibiBytes(513) + pageSize;
int pages = Math.toIntExact(pageCacheSize / pageSize);
MemoryAllocator mman = MemoryAllocator.createAllocator("2 GiB", GlobalMemoryTracker.INSTANCE);
SwapperSet swappers = new SwapperSet();
long victimPage = VictimPageReference.GetVictimPage(pageSize, GlobalMemoryTracker.INSTANCE);
PageList pageList = new PageList(pages, pageSize, mman, swappers, victimPage, Long.BYTES);
// Verify we end up with the correct number of pages.
assertThat(pageList.PageCount, @is(pages));
// Spot-check the accessibility in the bulk of the pages.
IntStream.range(0, pages / 32).parallel().forEach(id => verifyPageMetaDataIsAccessible(pageList, id * 32));
// Thoroughly check the accessibility around the tail end of the page list.
IntStream.range(pages - 2000, pages).parallel().forEach(id => verifyPageMetaDataIsAccessible(pageList, id));
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: public Void handle(org.neo4j.causalclustering.core.consensus.RaftMessages_NewEntry_Request newEntryRequest) throws Exception
public override Void Handle(Org.Neo4j.causalclustering.core.consensus.RaftMessages_NewEntry_Request newEntryRequest)
{
BoundedNetworkWritableChannel sizeBoundChannel = new BoundedNetworkWritableChannel(Channel.byteBuf(), ByteUnit.gibiBytes(1));
Marshal.marshal(newEntryRequest.Content(), sizeBoundChannel);
return(null);
}