最近在学习ES的一些东西，遇到了一些问题，整理一下，希望可以帮助到也在学习ES的小伙伴

1、问题1

报错场景：
单机启动多ES集群
报错信息：

[2024-02-24T22:58:10,567][WARN ][o.e.t.RemoteClusterService] [cluster0node] failed to update seed list for cluster: cluster1
org.elasticsearch.transport.ConnectTransportException: [][127.0.0.1:9301] connect_exceptionat org.elasticsearch.transport.TcpTransport$ChannelsConnectedListener.onFailure(TcpTransport.java:1299) ~[elasticsearch-7.1.0.jar:7.1.0]at org.elasticsearch.action.ActionListener.lambda$toBiConsumer$2(ActionListener.java:99) ~[elasticsearch-7.1.0.jar:7.1.0]at org.elasticsearch.common.concurrent.CompletableContext.lambda$addListener$0(CompletableContext.java:42) ~[elasticsearch-core-7.1.0.jar:7.1.0]at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:859) ~[?:?]at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:837) ~[?:?]at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506) ~[?:?]at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2159) ~[?:?]at org.elasticsearch.common.concurrent.CompletableContext.completeExceptionally(CompletableContext.java:57) ~[elasticsearch-core-7.1.0.jar:7.1.0]at org.elasticsearch.transport.netty4.Netty4TcpChannel.lambda$new$1(Netty4TcpChannel.java:72) ~[?:?]at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511) ~[?:?]at io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:504) ~[?:?]at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:483) ~[?:?]at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424) ~[?:?]at io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:121) ~[?:?]at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.fulfillConnectPromise(AbstractNioChannel.java:327) ~[?:?]

报错解决：
后台启动ES命令。在启动命令的最后添加-d选项即可，如下图：

//...代表其他启动参数,省略
bin/elasticsearch ... -d