Broken Pipe 在 neo4j 浏览器中展开子关系时出错

Question

I import data to neo4j, and run it locally through locahost:7474. Every thing works fine except that when I click the 'Expand/Collapse child relationships' of a node (about 1000 relationships) in neo4j browser, the browser crashed. I checked the debug.log, there is an error:

2019-09-24 00:17:56.041+0000 ERROR [o.n.b.t.p.HouseKeeper] Fatal error occurred when handling a client connection: [id: 0xab13859e, L:/127.0.0.1:7687 ! R:/127.0.0.1:65375] Broken pipe
java.io.IOException: Broken pipe
        at sun.nio.ch.FileDispatcherImpl.write0(Native Method)
        at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:47)
        at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93)
        at sun.nio.ch.IOUtil.write(IOUtil.java:51)
        at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:471)
        at io.netty.channel.socket.nio.NioSocketChannel.doWrite(NioSocketChannel.java:405)
        at io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:938)
        at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.forceFlush(AbstractNioChannel.java:367)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:650)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:591)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:508)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:470)
        at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:909)
        at java.lang.Thread.run(Thread.java:748)

I searched a lot, some people said I should increase max open files, I ran the command launchctl limit maxfiles , I got the max open files is 65535. I think that is enough.

Anybody have any idea want happened? I am guessing this may result from some configuration of neo4j.

Answer 1

The exception

java.io.IOException: Broken pipe

means that the other side stopped communicating and didn't shutdown gracefully. In your case the other side is the browser. So the error in the log is not important from server point of view.

The Neo4j browser is not designed to work with such a high number of nodes and relationships on the screen. Getting a better machine (with faster CPU and more memory) might help, but generally it is easier to be more specific in your query.

Also try to uncheck Connect result nodes in browser settings (cog on bottom right). Sometimes it is the relationships between the new nodes that cause the issue.