vert.x 获取 - 未能创建子事件循环

Question

我正在创建大约 150 个大小约为 5MB 的文件。 Vertx 文件 API 在创建 10-15 个文件后随机给出异常 "failed to create a child event loop"。

（我正在使用 vertx3 和 java8）

下面是我的代码片段（在我得到回调后，我只再次调用该函数来创建下一个文件。因此，文件创建永远不会并发）：

Vertx.vertx().fileSystem().writeFile(filepath,
       Buffer.buffer(dataList.toString()), result -> {
 if (result.succeeded()) {
   System.out.println("File written");
 } else {
  System.err.println("Oh oh ..." + result.cause());
 }
 lambda.callback();
});

下面是我的异常堆栈跟踪：

java.lang.IllegalStateException: failed to create a child event loop
    at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:68)
    at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:49)
    at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:61)
    at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:52)
    at io.vertx.core.impl.VertxImpl.<init>(VertxImpl.java:132)
    at io.vertx.core.impl.VertxImpl.<init>(VertxImpl.java:126)
    at io.vertx.core.impl.VertxImpl.<init>(VertxImpl.java:122)
    at io.vertx.core.impl.VertxFactoryImpl.vertx(VertxFactoryImpl.java:34)
    at io.vertx.core.Vertx.vertx(Vertx.java:78)
    at rc_datawarehouse.CsvToJsonChunkWriter.writeCsvChunkToFiles(CsvToJsonChunkWriter.java:73)
    at rc_datawarehouse.CsvToJsonReadWrite.lambda(CsvToJsonReadWrite.java:119)
    at rc_datawarehouse.CsvToJsonReadWrite$$Lambda/1470881859.handle(Unknown Source)
    at io.vertx.core.file.impl.AsyncFileImpl.handleData(AsyncFileImpl.java:335)
    at io.vertx.core.file.impl.AsyncFileImpl.lambda$doRead5(AsyncFileImpl.java:320)
    at io.vertx.core.file.impl.AsyncFileImpl$$Lambda/1067800899.handle(Unknown Source)
    at io.vertx.core.file.impl.AsyncFileImpl.lambda$done9(AsyncFileImpl.java:408)
    at io.vertx.core.file.impl.AsyncFileImpl$$Lambda/1632681662.handle(Unknown Source)
    at io.vertx.core.impl.ContextImpl.lambda$wrapTask(ContextImpl.java:314)
    at io.vertx.core.impl.ContextImpl$$Lambda/1780132728.run(Unknown Source)
    at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:357)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:357)
    at io.netty.util.concurrent.SingleThreadEventExecutor.run(SingleThreadEventExecutor.java:111)
    at java.lang.Thread.run(Unknown Source)
Caused by: io.netty.channel.ChannelException: failed to open a new selector
    at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:128)
    at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:120)
    at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:87)
    at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:64)
    ... 22 more
Caused by: java.io.IOException: Unable to establish loopback connection
    at sun.nio.ch.PipeImpl$Initializer.run(Unknown Source)
    at sun.nio.ch.PipeImpl$Initializer.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.nio.ch.PipeImpl.<init>(Unknown Source)
    at sun.nio.ch.SelectorProviderImpl.openPipe(Unknown Source)
    at java.nio.channels.Pipe.open(Unknown Source)
    at sun.nio.ch.WindowsSelectorImpl.<init>(Unknown Source)
    at sun.nio.ch.WindowsSelectorProvider.openSelector(Unknown Source)
    at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:126)
    ... 25 more
Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect
    at sun.nio.ch.Net.connect0(Native Method)
    at sun.nio.ch.Net.connect(Unknown Source)
    at sun.nio.ch.Net.connect(Unknown Source)
    at sun.nio.ch.SocketChannelImpl.connect(Unknown Source)
    at java.nio.channels.SocketChannel.open(Unknown Source)
    at sun.nio.ch.PipeImpl$Initializer$LoopbackConnector.run(Unknown Source)
    ... 34 more

Answer 1

我从论坛得到了答案here（感谢 Jez）

Vertx.vertx() 是罪魁祸首。它每次都会创建一个新的顶点，导致多个事件循环，这似乎是问题所在。

我将它缓存在一个变量中，而不是每次都使用 Vertx.vertx() 而且它起作用了

cachedVertx.fileSystem().writeFile(...)

vert.x 获取 - 未能创建子事件循环

vert.x getting - failed to create a child event loop

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