使用Siddhi与NATS服务器的连接问题

Question

我想使用Siddhi流处理器从NATS服务器读取消息。我已经安装了以下软件：

• NATS服务器v2.1.6（在独立服务器上）
• Siddhi siddhi-runner-5.1.2（作为同一LAN上另一台服务器上的二进制独立文件）
• NATS 2.0.10的Siddhi扩展，具有以下依赖性：protobuf-java-3.9.1.jar，java-nats-streaming-2.2.2.jar，jnats-2.6.5.jar（无论如何我都不使用流式传输选项）

我使用以下siddhi应用程序：

@App:name("TestNATS")

@source(type='nats', @map(type='text'), destination='test.message', bootstrap.servers='nats://192.168.50.173:4222')
define stream inputStream (name string, age int, country string);

@sink(type='log', prefix='LOGGER')
define stream OutputStream(name string, age int, country string);

@info(name='HelloWorldQueryNATS')
from inputStream
select name, age, country
insert into OutputStream;

[Siddhi启动时似乎可以毫无问题地连接到NATS server，但是在最初的握手之后，Siddhi抛出了以下exception：

[2020-04-10 10:55:00,441]  INFO {org.wso2.msf4j.internal.websocket.WebSocketServerSC} - All required capabilities are available of WebSocket service component is available.

[2020-04-10 10:55:00,549]  INFO {org.wso2.msf4j.analytics.metrics.MetricsComponent} - Metrics Component is activated

[2020-04-10 10:55:00,552]  INFO {org.wso2.carbon.databridge.agent.internal.DataAgentDS} - Successfully deployed Agent Server

[2020-04-10 10:55:01,163]  INFO {org.wso2.carbon.analytics.idp.client.core.utils.IdPServiceUtils} - Enabling default IdPClient Local User Store as configuration is not overridden.

[2020-04-10 10:55:01,167]  INFO {org.wso2.carbon.analytics.idp.client.core.utils.IdPServiceUtils} - IdP client of type 'local' is started.

[2020-04-10 10:55:06,915] ERROR {io.siddhi.extension.io.nats.source.NATSSource} - Error while connecting to NATS server at destination: test.message

[2020-04-10 10:55:06,918] ERROR {io.siddhi.core.stream.input.source.Source} - Error on 'TestNATS'. Error while connecting to NATS server at destination: test.message Error while connecting at Source 'nats' at 'inputStream'. Will retry in '5 sec'. io.siddhi.core.exception.ConnectionUnavailableException: Error while connecting to NATS server at destination: test.message


Caused by: java.io.IOException: stan: connect request timeout

并连续重新启动连接过程，因此在NATS server的日志中，我们可以看到以下消息：

cid:1 - Client connection created

cid:1 - <<- [CONNECT"lang":"java","version":"2.6.0","name":"1586508901596_66035_83044","protocol":1,"verbose":false,"pedantic":false,"tls_required":false,"echo":true}]

cid:1 - <<- [PING]

cid:1 - ->> [PONG]

cid:1 - <<- [SUB _STAN.acks.TSHykWgo2B6Lv2xW8b1Bfd 1]

cid:1 - <<- [SUB _INBOX.TSHykWgo2B6Lv2xW8b1BaH 2]

cid:1 - <<- [SUB _INBOX.TSHykWgo2B6Lv2xW8b1Bcx 3]

cid:1 - <<- [SUB _INBOX.4bm5CWKphBwldfvnGCxxJd.* 4]

cid:1 - <<- [PUB _STAN.discover.test-cluster _INBOX.4bm5CWKphBwldfvnGCxxJd.4bm5CWKphBwldfvnGCxxa9 88]

cid:1 - <<- MSG_PAYLOAD: ["\n\x191586508901596_66035_83044\x12\x1d_INBOX.TSHykWgo2B6Lv2xW8b1BaH\x18\x01\"\x16TSHykWgo2B6Lv2xW8b1BXb(\x050\x03"]

cid:1 - Client Ping Timer

cid:1 - ->> [PING]

cid:1 - <<- [PONG]

cid:1 - <<- [UNSUB 1]

cid:1 - <-> [DELSUB 1]

cid:1 - <<- [UNSUB 2]

cid:1 - <-> [DELSUB 2]

cid:1 - <<- [UNSUB 3]

cid:1 - <-> [DELSUB 3]

cid:1 - Client connection closed

cid:1 - <-> [DELSUB 4]

cid:2 - Client connection created

NATS server与我使用Nodejs的发布订阅应用程序使用的相同，并且工作正常。我也尝试使用最后一个Siddhi docker程序包，但结果是相同的。

哪里可能是错误？

Answer 1

使用nats-streaming-server而不是nats-server，不再出现连接问题。谢谢。