[MC-31577] Some arrows shot into a block never despawn

Arrows shot from skeletons and (likely) infinity bows as well do not despawn over time (didn't test infinity because I don't have it yet..). Normally, these dissapear after 5 minutes of sitting like any dropped item, xp orb or similar entity. These count as entities in the world, so they can contribute to entity lag like that of item frames, minecarts, glitched items or other things.

The server I've been playing the snapshots on has a skeleton farm within the spawn chunks (meaning that the area is loaded 100% of the time). After 2 days or so of this farm being used briefly after 37b release, roughly 700 arrows have accumulated there since skeletons can see through the corner of blocks sometimes, depending on the block and angle, and shoot at you. Normally this isn't a problem, but the arrows don't despawn.. and it's within spawn chunks, so the lag from them is always there.

The picture with the sky shot is outside of spawn/skeleton farm range, standard entity count of 110ish. The picture with the furnace + chest is within the same room as the farm, but looking away (800+ entities). Proof shot of the skeleton farm is there. And the picture with the dispenser is the most direct shot of the arrows. See those glitched out ones inside it? Yeah, 680 or so. You can also see the fps drop, which I didn't really look at until now (37 on far to 10 on tiny).

Linked issues

is duplicated by 16

MC-32204 arrows do not despawn from farmland Resolved

MC-33330 Arrows Not Despawning Resolved

MC-34113 Arrows Don't Despawn Resolved

MC-34582 Arrows are entities, No despawn Resolved

MC-38974 Sugar Cane + Light Source FPS issue Resolved

11 more links

Attachments

Comments 51

CubeTheThird 2013-09-20T00:20:30Z

Unable to reproduce.

Grave 2013-09-20T01:27:43Z

It seems to be fixed in 13w38a. Arrows seem to despawn within 30-60 seconds after being shot by skeletons now. I threw up about 1500 of them from skeletons for testing's sake, and it took far less than 5 minutes for them to despawn if no updates occur to them (break the block they're stuck to, etc will reset the despawn timer). That was done in singleplayer, I'll have to see if it's any different on the server I'll be playing snapshots on.

Grave 2013-09-20T01:49:37Z

I checked on the server, and the arrow count didn't go down at all when waiting for the arrows to despawn.. That sucks.

Grave 2013-09-24T12:08:16Z

Still no change on the server, but I think they changed the entity ID if that's possible. If they used the same one from 37a/b in 38a-c, it may fix itself. Otherwise, I don't know. I just know that no new arrows are stacking up. All old ones are still all over the world.

kumasasa 2013-09-30T21:40:02Z

Reopened, see MC-33330

41 more comments

Ben Golder 2013-09-30T22:04:42Z

Too Many Entities

Ben Golder 2013-09-30T22:05:22Z

Also having the same issue.

David Harmon 2013-10-10T18:10:51Z

Also seeing it in13w39b.

Freso Fenderson 2013-10-14T08:57:25Z

Still seeing this in 13w41b. Creates major lag that only increases with time as more arrows are accumulated.

Brad Gray 2013-10-14T09:35:15Z

I can confirm this also. Very bad since the I average about 200fps but am now only getting 50fps. The lag on the server has also increased dramatically (I have over 1500 ping compared to 500 ping (I'm an Aussie. woo to amazingly crap internet)).

Nathan Adams 2013-10-14T10:42:16Z

I think the issue was that we don't persist the lifetime of an arrow, so if it was saved/loaded during its 60-second life span then it resets.

David Harmon 2013-10-14T22:46:22Z

I am not so sure that the bug depends on saving/loading the world. I think I've had arrows persist abnormally long even during a single session.

David Barclay 2013-10-17T04:11:41Z

I am seeing this issue as well in my singleplayer survival world.
Over 300 loaded entities at all times, played near the loaded arrows for many hours across multiple sessions without this number dropping.
This is causing framerate drops throughout my entire world as they are in spawn chunks.

Arrows in a creative world did get despawned, not related to spawn chunks as arrows despawned when I tested this.

13w41b, Windows 7, 64bit Oracle Java.

CubeTheThird 2013-10-17T04:15:56Z

@David Barclay, note this bug has been listed as fixed for future release version (likely next snapshot).

flippedcracker 2013-10-23T21:40:15Z

I'm still seeing this issue in 1.7.1. Arrows that got stuck in a previous version are not despawning now.

kumasasa 2013-10-23T22:15:15Z

@flippedcracker : Arrows of 1.6 or of a 1.7 snapshot ?

flippedcracker 2013-10-23T22:20:51Z

@Kumasasa a 1.7 snapshot. Server map created with 13w41b, updated to 13w42a, and then 1.7.1.

kumasasa 2013-10-23T22:24:27Z

@flippedcracker: Then it's a non-issue. Simply delete the world.

flippedcracker 2013-10-23T22:42:20Z

@Kumasasa And what about everything that's been built by all the members of the server? Just start over?

kumasasa 2013-10-23T22:52:30Z

Rule of thumb: Never make something productive with an alpha version. Everything will happen.
Either you face the risk of throwing stuff away and use snapshots or you don't and use only release versions.

flippedcracker 2013-10-23T23:27:17Z

@Kumasasa This should be able to be fixable. Opening the world in 1.6.4, the arrows despawn properly. But reopening the world in 1.7.1 brings the arrows back.

CubeTheThird 2013-10-23T23:29:34Z

You could probably run some kind of mcedit filter to delete all the arrow entities.

clamlol 2013-11-05T08:05:37Z

still present in 1.7.2, but can be fixed by reloading the world (reloading removed 750 out of 760 arrows in my surv world)
@cubethethird is there mcedit for 1.7? The site says it hasn't been updated since may

CubeTheThird 2013-11-05T13:47:42Z

A full release has not been released since then, however the dev build may be compatible (I have not tried it). If you are concerned that it is not stable (which is likely) it may be better to wait for a full release.

8j0KVEUciir2 2013-11-05T22:15:53Z

Meanwhile these persistent arrow entities are wreaking havoc for some of us who have the (unfortunate) luck of having built their base near a skeleton spawner. Going into Creative and simply burning everything off worked partially, as did reloading (although reloading left INVISIBLE persistent arrows for me, that I could not even burn away) but ultimately, I can only see a fix on a coding level resolving this.

clamlol 2013-11-06T04:37:32Z

just did some more testing at my skeleton farm. It appears that moving the arrows completely into a solid block's space by reloading the world (the arrows fall a little before the blocks load) will delete them. Not 100% sure tho. Also not sure if just enclosing them with blocks would suffice, although I don't think it would.

Seeing as this hasn't been completely fixed yet, could the mods please reopen this?

8j0KVEUciir2 2013-11-08T17:00:55Z

Tried similar things and even that did not fully work for me; burning them off partially worked, reloading partially worked, filling the space up with blocks partially worked but ultimately, even the combination of such did not work to the full extent. Invisible, persistent arrows would remain (confirmed by audio queue – the arrows would still make their falling sound when the block they were stuck in was destroyed, just no arrows were visually shown). Please re-open, this does need to be addressed ASAP as Skeleton farms are amongst the most lucrative.

8j0KVEUciir2 2013-11-11T12:20:05Z

Can we please see this re-opened or MC-32204 assigned? Because the issue is far from actually being 'Resolved', contrary to what the bug tracker suggests. 😉

kumasasa 2013-11-11T19:33:15Z

Cannot reproduce this issue (except shooting arrows in farmland), please provide exact steps to reproduce.

8j0KVEUciir2 2013-11-11T20:26:59Z

Step 1: Single Player Survival, 1.7.2, default biomes, seed: -1532923692246250057
Step 2: At x: -74, y: 33, z: -268 you will find a Skeleton Spawner, build a 9x9 water based skeleton farm around this, dropping the skeletons through a central hole below the spawner into a 1x1 hole/trap.
Step 3: Eventually, the arrows shot by the skeletons should accumulate in the rocks surrounding the 1x1 hole and fail to despawn.

At least, that is what did it for me, in the exact seed and location I experienced it.

After experiencing severe FPS drop and eventually having it pinned down to the skeleton spawner I went into Creative and decided to simply clear the arrows and just by audio queue alone I could tell it was literally in the hundreds if not easily 1k+ arrows that had accumulated. At some point during the time I played this seed I ended up exploring the world (filling in a max level map, so, quite the distance away) and not even that caused the arrows to despawn.

kumasasa 2013-11-11T20:29:23Z

Did not reproduce, but the steps you've provided should be sufficient.

8j0KVEUciir2 2013-11-12T13:07:53Z

Try the following:

Pulse Generator hooked up to a command block that /summon's Skeletons into a trap/collection as described above.
Give it some time to generate a ridiculous number of skeletons (a couple of hundred, shouldn't take long with a sufficiently fast generator).
Provoke the Skeletons (either by standing amongst them with a level 5 Damage Reduction buff or some other fashion).
This should cause them to start firing their bows and eventually cause them to aggro on each other.
After some time, just despawn them by switching to Peaceful.

After I had performed that set up (in a superflat world, just to experiment with this bug), the phenomenon did trigger. Currently standing in that 1x1 hole I made for the skeletons, looking at a couple of stone blocks containing hundreds of arrows which do not despawn.

This to me suggests it is somehow linked to the volume of arrows; the number. ie; whenever the number of arrows that exist exceeds a certain amount, their despawning behaviour breaks.

Noproct 2013-12-07T08:29:57Z

This issue is still present in 1.7.3 pre-release. Skeletons had a 'small' fight in a skeleton spawner on my Vanilla SMP server. The arrows (600-700) after being loaded for over 10 hours have still not despawned.

Bob Smith 2013-12-07T16:08:05Z

I duplicated this a bit ago, missed arrows still there more than 30 minutes after 200 skeletons killed each other off. (1.7.2)

Steve Anderson 2013-12-08T17:08:46Z

I can confirm this one. Vanilla 1.7.2 server and clients. First noticed when an arrow stuck in sand not far from world spawn persisted for many in-game days (was used as a navigational aide); and more recently in a skeleton grinder whenever skeletons have a line-of-sight on a player and many shoot, there are hundreds of persistent arrows embedded in nearby structures.

Bob Smith 2013-12-09T13:54:26Z

Still present in 1.7.4 pre-release

Breaking the block the arrows are stuck in and allowing them to fall to the next block allows them to despawn in my 1.7.2 single player game.

Ben W 2013-12-10T19:31:05Z

Cannot confirm in 1.7.4 release. Arrows shot from a /summon'd skeleton in singleplayer, as well as those shot from an infinity bow, were able to despawn normally.

Freso Fenderson 2013-12-12T08:02:44Z

@Ben W: How many skeletons did you spawn? Per previous comments, the issue does not seem to be with single/few skeletons, so there might be some overloading come into play. Try to spawn a hundred (possibly in a small space, such as on a single block) and let them have a go at each other to pile up the arrows. Then leave the game while they fight and come back to it some time later. I have arrows in a skeleton spawner in a 1.7.3 world that are still there after some hours of idling.I haven't been by with 1.7.4 yet, but I suspect I will have to clear them out using MCEdit again at some point.

Marshall Wicker 2013-12-15T22:02:49Z

I have more than 2,000 arrows in my spawner walls from where I stood and they shot at me through the corner while afk'ing

Andrew Kampen 2013-12-20T17:49:54Z

This is definitely still an issue. I wandered back to my home base on my private SMP server to use my skeleton grinder, and crashed down to 19 fps from my usual 120. 4400+ entities.

I've been letting people use the skeleton grinder and apparently they don't stand where I usually do. Breaking the blocks the arrows are trapped and allowing them to fall seems to permit despawning.

Vanilla server.

Austin Brock 2013-12-25T12:11:28Z

On a 1.7.2 server, this happened. Just upgraded to 1.7.4 though.

Did not realise there was an update because 1.7.4 client works on a 1.7.2 server.

Silly.

Caleb Berry 2014-01-05T09:32:01Z

I have the same error on my server I attempted to shot them down to the void and it just causes more lag now.

FPS freezes will happen (0-3 FPS)

Dan Keller 2014-01-22T15:27:55Z

Oddly enough I think I might have a work-around. I have a skeleton spawner XP farm on my in which this has occurred. When arrows bunch up, I've dug a hole down 2-3 meters to let the arrows fall then cover the arrows back up. I think the entity count has dropped the next time I return and look in the direction of the buried arrows. Not a fix for the bug but might help with lag. Perhaps others can confirm.

That, of course, is not a very reasonable work-around if the arrows are distributed over a large area.

I'm hoping that with 1.8 as an OP I can "kill" the arrows via a command from time to time.

NekoJonez 2014-01-22T15:30:48Z

A farm I use is one with the water elevator. In the water elevator itself there are tons of arrows as well who don't despawn.

David Kowis 2014-01-22T16:19:38Z

So our workaround is this: https://github.com/Fenixin/Minecraft-Region-Fixer

Obviously this requires access to the server, but it has saved us from stupid amounts of entities.

Talven81 2014-01-22T16:28:14Z

There will be another way to deal with arrows in 1.8, not a fix but a workaround and will kill arrows in loaded chunks.

Command Block or Issued Command:
kill @e[type=Arrow]

Tyron 2014-02-25T22:36:07Z

Did my previous comment just got deleted without any notice?

Anyhow, here a more informative comment about this issue: This one is in my opinion the most annoying bug in 1.7.x and causes unecessary lag, please fix this soon!
The issue is not just temporary, e.g. I've been having an arrow stuck in the ground in front of my house for the last 2 months now. I've restarted my server a couple of times inbetween so that did not fix it. (I'm using 1.7.4, was it perhaps fixed in 1.7.4 but broken arrows from 1.7.2 still persist or so?)

So I checked with my world save with some code. Just around my house, I'm finding over a hundred unique arrows stuck somewhere. I don't know why but all relevant arrow variables related to despawning are Zero, expect its coordinates. When I shoot new arrows, these seems to be ok though. I hope this can be of some help to someone.

One example:

found arrow with entityid 1493 (total found: 116)
motion: -0.0/0.0
arrowshake: 0
ticks in air 0
inground: 0
xtile: 56
ytile: 41
ztile: -375
life: 0
intile: 0
indata: 0

Variables printed with this (badly written) forgecode ('started' is set at FMLServerStartedEvent):

Hashtable<Integer, EntityArrow>arrows = new Hashtable<Integer, EntityArrow>();
    
    @SubscribeEvent 
    public void onEntityUpdate(EntityEvent event) {
    	if (!started) return;
    	
    	if (event.entity instanceof EntityArrow) {
    		EntityArrow arrow = (EntityArrow)event.entity;
    		
    		if ((!arrows.containsKey(arrow.getEntityId()) && arrow.posX != 0)) {
    			System.out.println("found arrow with entityid " + arrow.getEntityId() + " (total found: " + arrows.size() + ")");
	    		
    			arrows.put(arrow.getEntityId(), arrow);
    			
    			System.out.println("motion: " + arrow.motionX + "/" + arrow.motionZ);
    			System.out.println("arrowshake: " + arrow.arrowShake);	
                  
    			try {
    				Field field = EntityArrow.class.getDeclaredField("ticksInAir");
    				field.setAccessible(true);
        	    	int ticksinair = (Integer)field.get(arrow);
        	    	System.out.println("ticks in air " + ticksinair);
    			} catch (Exception e) {
    				System.out.println(e.getMessage());
    			}
    			
	    		NBTTagCompound nbttagcompound = new NBTTagCompound();
	            arrow.writeEntityToNBT(nbttagcompound);
	            
	            System.out.println("inground: " + nbttagcompound.getByte("inGround"));
	            System.out.println("xtile: " + nbttagcompound.getShort("xTile"));
	            System.out.println("ytile: " + nbttagcompound.getShort("yTile"));
	            System.out.println("ztile: " + nbttagcompound.getShort("zTile"));
	            
	            System.out.println("life: " + nbttagcompound.getShort("life"));
	            System.out.println("intile: " + nbttagcompound.getByte("inTile"));
	            System.out.println("indata: " + nbttagcompound.getByte("inData"));
    		}
    	}
    }

[Edit:]
I just broke the block beneath on of the never despawning arrows and it despawned! So looks pretty surely to me like 1.7.2 arrows saved to the world don't despawn in 1.7.4. - perhaps some missing nbt data?

Russell Zahm 2014-04-06T22:29:35Z

Evedence of this bug can be found in the most recent BdeoubleO mindcrack episode.

When Bdubs starts taking down the fairy over Town hall 2 arrows are found inside the fairy. These same arrows were fired at MCgamer when he was building the fairy at the beginning of February during a Mindcrack @ Dusk Livestream.

Jump to 13:17
https://www.youtube.com/watch?v=zqnQ60kORkw

Mindcrack server is running Snapshot 14w11b Arrows were shot at Mcgamer when the server was running 1.7.2

You can actually find these same arrows for your self by going on the playmindcrack server. Go to Museum Season 4 map. Climb on top of town hall and look up at the back side of the fairy in the head in the yellow wool blocks.

galaxy_2alex 2014-10-25T20:25:48Z

Is this still a concern in the current Minecraft version 1.8.1 Prerelease 3 / Launcher version 1.5.3 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

marcono1234 2015-05-10T12:31:33Z

Based on @unknown's comment the *onGround* tag was invalid. As soon as it is in a block, it should have *inGround:1b*. The *inTile* tag is wrong as well, 0 means Air so it thinks the arrow is still flying (in 1.8.x the *inTile* tag is an empty string when it didn't hit a block). One thing which would have been interesting is if the *xTile*, *yTile* and *zTile* refered to a block or to air.

I can however not confirm this

JUE13 2016-02-04T09:29:41Z

Can not reproduce in 16w05a