我试图了解 Spring Boot 如何关闭分布式 Hazelcast 缓存。当我连接然后关闭第二个实例时，我收到以下日志：
2021-09-20 15:34:47.994 INFO 11492 --- [.IO.thread-in-0] c.h.internal.nio.tcp.TcpIpConnection : [localhost]:8084 [dev] [4.0.2] Initialized new cluster connection between /127.0.0.1:8084 and /127.0.0.1:60552
2021-09-20 15:34:54.048 INFO 11492 --- [ration.thread-0] c.h.internal.cluster.ClusterService : [localhost]:8084 [dev] [4.0.2]
Members {size:2, ver:2} [
Member [localhost]:8084 - 4c874ad9-04d1-4857-8279-f3a47be3070b this
Member [localhost]:8085 - 2282b4e7-2b6d-4e5b-9ac8-dfac988ce39f
]
2021-09-20 15:35:11.087 INFO 11492 --- [.IO.thread-in-0] c.h.internal.nio.tcp.TcpIpConnection : [localhost]:8084 [dev] [4.0.2] Connection[id=1, /127.0.0.1:8084->/127.0.0.1:60552, qualifier=null, endpoint=[localhost]:8085, alive=false, connectionType=MEMBER] closed. Reason: Connection closed by the other side
2021-09-20 15:35:11.092 INFO 11492 --- [ached.thread-13] c.h.internal.nio.tcp.TcpIpConnector : [localhost]:8084 [dev] [4.0.2] Connecting to localhost/127.0.0.1:8085, timeout: 10000, bind-any: true
2021-09-20 15:35:13.126 INFO 11492 --- [ached.thread-13] c.h.internal.nio.tcp.TcpIpConnector : [localhost]:8084 [dev] [4.0.2] Could not connect to: localhost/127.0.0.1:8085. Reason: SocketException[Connection refused: no further information to address localhost/127.0.0.1:8085]
2021-09-20 15:35:15.285 INFO 11492 --- [ached.thread-13] c.h.internal.nio.tcp.TcpIpConnector : [localhost]:8084 [dev] [4.0.2] Connecting to localhost/127.0.0.1:8085, timeout: 10000, bind-any: true
2021-09-20 15:35:17.338 INFO 11492 --- [ached.thread-13] c.h.internal.nio.tcp.TcpIpConnector : [localhost]:8084 [dev] [4.0.2] Could not connect to: localhost/127.0.0.1:8085. Reason: SocketException[Connection refused: no further information to address localhost/127.0.0.1:8085]
2021-09-20 15:35:17.450 INFO 11492 --- [cached.thread-3] c.h.internal.nio.tcp.TcpIpConnector : [localhost]:8084 [dev] [4.0.2] Connecting to localhost/127.0.0.1:8085, timeout: 10000, bind-any: true
2021-09-20 15:35:19.474 INFO 11492 --- [cached.thread-3] c.h.internal.nio.tcp.TcpIpConnector : [localhost]:8084 [dev] [4.0.2] Could not connect to: localhost/127.0.0.1:8085. Reason: SocketException[Connection refused: no further information to address localhost/127.0.0.1:8085]
2021-09-20 15:35:19.474 WARN 11492 --- [cached.thread-3] c.h.i.n.tcp.TcpIpConnectionErrorHandler : [localhost]:8084 [dev] [4.0.2] Removing connection to endpoint [localhost]:8085 Cause => java.net.SocketException {Connection refused: no further information to address localhost/127.0.0.1:8085}, Error-Count: 5
2021-09-20 15:35:19.475 INFO 11492 --- [cached.thread-3] c.h.i.cluster.impl.MembershipManager : [localhost]:8084 [dev] [4.0.2] Removing Member [localhost]:8085 - 2282b4e7-2b6d-4e5b-9ac8-dfac988ce39f
2021-09-20 15:35:19.477 INFO 11492 --- [cached.thread-3] c.h.internal.cluster.ClusterService : [localhost]:8084 [dev] [4.0.2]
Members {size:1, ver:3} [
Member [localhost]:8084 - 4c874ad9-04d1-4857-8279-f3a47be3070b this
]
2021-09-20 15:35:19.478 INFO 11492 --- [cached.thread-7] c.h.t.TransactionManagerService : [localhost]:8084 [dev] [4.0.2] Committing/rolling-back live transactions of [localhost]:8085, UUID: 2282b4e7-2b6d-4e5b-9ac8-dfac988ce39f
似乎当我关闭它时，第二个实例没有报告它正在正确关闭第一个实例。当它在几秒钟内无法连接到它并因此从集群中删除后，我们会收到警告。
2021-09-20 15:42:03.516 INFO 4900 --- [.ShutdownThread] com.hazelcast.instance.impl.Node : [localhost]:8085 [dev] [4.0.2] Running shutdown hook... Current state: ACTIVE
2021-09-20 15:42:03.520 INFO 4900 --- [ionShutdownHook] o.s.b.w.e.tomcat.GracefulShutdown : Commencing graceful shutdown. Waiting for active requests to complete
2021-09-20 15:42:03.901 INFO 4900 --- [tomcat-shutdown] o.s.b.w.e.tomcat.GracefulShutdown : Graceful shutdown complete
它似乎正在尝试运行关闭挂钩，但它所做的最后一个报告仍然是“ACTIVE”，并且它永远不会像本文文章中提到的那样进入“SHUTTING_DOWN”或“SHUT_DOWN”。
pom.xml
...
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
...
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
<groupId>com.hazelcast</groupId>
<artifactId>hazelcast-all</artifactId>
<version>4.0.2</version>
</dependency>
</dependencies>
...
只是为了添加一些上下文。我有以下应用程序.yml
---
server:
shutdown: graceful
以及以下 hazelcast.yaml
---
hazelcast:
shutdown:
policy: GRACEFUL
shutdown.max.wait: 8
network:
port:
auto-increment: true
port-count: 20
port: 8084
join:
multicast:
enabled: false
tcp-ip:
enabled: true
member-list:
- localhost:8084
所以我的理论是 Spring Boot 通过终止 hazelcast 来关闭它，而不是让它优雅地关闭。
如何使 Spring Boot 和 Hazelcast 正确关闭，以便其他实例认识到它正在关闭而不是“消失”？
这里有两件事在起作用。首先是终止实例而不是正常关闭的实际问题。另一个在日志中正确地看到它。
Hazelcast 默认情况下会注册一个关闭钩子，该钩子会在 JVM 退出时终止实例。
您可以通过设置此属性来完全禁用关闭钩子：
-Dhazelcast.shutdownhook.enabled=false
或者，您可以将策略更改为正常关闭
-Dhazelcast.shutdownhook.policy=GRACEFUL
但这会导致 Spring Boot 正常关闭 = 完成服务请求和 Hazelcast 实例同时关闭，从而导致问题。
要正确查看日志，请将日志记录类型设置为 slf4j：
-Dhazelcast.logging.type=slf4j
然后您将正确地看到来自 Hazelcast 的所有
info-Dlogging.level.com.hazelcast=TRACE
有效。
您配置属性的方式错误。 根据 docs 你的 hazelcast.yaml 应该是这样的：
hazelcast:
properties:
hazelcast.shutdownhook.enabled: false
然后你可以在春天做类似的事情
@PreDestroy
public void shutDownHazelcast() {
if (cacheParameters.isEnabled()) {
log.info("Gracefully shutdown hazelcast");
hazelcastInstance.shutdown();
}
}
您还可以使用配置进行 hazelcast 标准挂钩（请参阅 ClusterProperty）：
hazelcast.shutdownhook.enabled: true
#by default its TERMINATING!!!!
hazelcast.shutdownhook.policy: GRACEFUL
# seconds
hazelcast.graceful.shutdown.max.wait: 600