The bottleneck for transferring the file is probably not the process of reading data from disk. Presumably you are doing this to get the fastest download times that are possible. The stacktrace shows that you are using Files::readAllBytes to load files into memory. The real solution is to take a different approach. And I don't think it is a guaranteed solution. But that can have performance implications. If that happens, you get an OOME.ĪFAIK, the only thing you can do is to force more frequent garbage collections. However, this happens in the post-collection phase, so if the demand for / turnover of direct buffers is too great, it is possible that the collector won't be able to keep up. When the GC detects that a DirectByteBuffer is no longer referenced, a Cleaner is used to free the native memory. So increasing or decreasing the heap size won't help. They are allocated using Unsafe.allocateMemory which allocates 'native memory'. The actual memory buffers managed by DirectByteBuffer are not allocated in the heap. Is there some other way to avoid this memory problem? The problem occured after some time, but then when I tired running the same request again it seems like the garbage collection took care of whatever caused the problem, but this is not sufficient since the problem apparently still can occur. The problem still occured but now only spardic. But the heap is only around 1.6gb in size and not near the configured 4gb it can be.Īccording to some other answer ( ) in a similar question I tried running manual gc before returning this file. I found two rather large byte, which should be the file I want to return. Furthermore when this error occured I took a heapdump with jmap to analyze the current state.

I have set the heap size to 4096mb which I think should be large enough to handle this kinds of files. For the most part this will work fine but after some time the following error will be thrown: : Direct buffer memoryĪt (Bits.java:694) ~Īt .(DirectByteBuffer.java:123) ~Īt (ByteBuffer.java:311) ~Īt .Util.getTemporaryDirectBuffer(Util.java:241) ~Īt .IOUtil.read(IOUtil.java:195) ~Īt .FileChannelImpl.read(FileChannelImpl.java:159) ~Īt .ChannelInputStream.read(ChannelInputStream.java:65) ~Īt .ChannelInputStream.read(ChannelInputStream.java:109) ~Īt .ChannelInputStream.read(ChannelInputStream.java:103) ~Īt .read(Files.java:3105) ~Īt .readAllBytes(Files.java:3158) ~ Let's say, 10% per level of potency.I need to return a rather large file from a web request. We also need some way of making the player levitate midair without gaining or losing height with a Levitation 0 or Fast Falling 0 of some sort. Let's say, 5% per level of potency.ĭrowning: Increases speed of losing air in water.įast Falling: Increases speed of falling. Let's say, 0.5 blocks per level of potency. In essence, the effects we need to compensate the 'removal' of this 'features' are:

I really need this to work with 1.11 as I'm currently polishing up a map for Realms and it'd have to be in 1.11.Įdit: I can't post on Minecraft Suggestions so I thought maybe I could compile a list of ways they can make an official implementation. With an official implementation, I think we can go even further.Ĭan I get an opinion on this matter? Should they have 'fixed' this? Or can anyone think of a workaround for 1.11? I'd love to have these 'features' back, or at least have an official implementation of them because they were really cool. I can no longer make players super vulnerable to damage using Resistance -127. I can no longer make players levitate midair without going up or down with Levitation 0. For example, I can no longer completely freeze players by giving them Slowness 7 along with Jump Boost -127. I'm quite upset because there aren't any ways to achieve what could be done before in this update. Here's an old thread of someone mentioning this: Įssentially, this has been fixed. I could make resistance potions that make you super vulnerable to damage (take 10x damage). I could make a jump boost potion that completely stops you from jumping. For instance, I could make a levitation potion that swung you downwards onto the floor rapidly.

This would overflow to -127 and we could get a negative potion effect. Some background information: Before 1.11, mapmakers like myself could do this thing where we make potions with, say, an amplifier value of 128.

Buffer overflow minecraft