问题描述：数据同步大批量数据，同步到中途就会报EAS网络连接异常，但测试连接又是成功的。

aused by: kd.isc.iscb.util.except.ConnectionException: 网络连接[http://xx.xx.xx.xx:6888]异常,请前往连接管理-连接配置测试连接是否正常，如果测试异常可以尝试重新部署。

         at kd.isc.iscb.util.misc.NetUtil.asyncHttpInvoke(NetUtil.java:172)

         at kd.isc.iscb.util.misc.NetUtil.asyncHttpInvoke(NetUtil.java:156)

         at kd.isc.iscb.util.connector.client.AbstractRemoteContext.invoke(AbstractRemoteContext.java:24)

         at kd.isc.iscb.util.connector.client.RemotePreparedStatement.executeQuery(RemotePreparedStatement.java:118)

         at kd.isc.iscb.util.db.DbUtil.executeScalar(DbUtil.java:234)

         at kd.isc.iscb.util.connector.s.QueryValue.call(QueryValue.java:35)

         at kd.isc.iscb.util.script.statement.Invocation.call(Invocation.java:65)

         at kd.isc.iscb.util.script.Util.evalList(Util.java:128)

         at kd.isc.iscb.util.script.feature.control.loop.Return$1.eval(Return.java:43)

         at kd.isc.iscb.util.script.Util.eval(Util.java:105)

         at kd.isc.iscb.util.script.statement.Block.eval(Block.java:41)

         at kd.isc.iscb.util.script.statement.Block.eval(Block.java:34)

         at kd.isc.iscb.util.script.Util.eval(Util.java:105)

         at kd.isc.iscb.util.script.parser.Program.eval(Program.java:58)

         at kd.isc.iscb.util.script.Script.eval(Script.java:229)

         at kd.isc.iscb.util.script.Script.eval(Script.java:217)

         at kd.isc.iscb.platform.core.vc.ScriptRule.cast(ScriptRule.java:55)

         at kd.isc.iscb.platform.core.vc.ValueConversionRuleProxy.cast(ValueConversionRuleProxy.java:41)

         at kd.isc.iscb.platform.core.vc.ValueConversionRuleFactory.innerRun(ValueConversionRuleFactory.java:72)

         at kd.isc.iscb.platform.core.vc.ValueConversionRuleFactory.run(ValueConversionRuleFactory.java:63)

         ... 21 more

Caused by: java.net.ConnectException: Connection refused (Connection refused)

         at java.net.PlainSocketImpl.socketConnect(Native Method)

         at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)

         at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)

         at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)

         at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)

         at java.net.Socket.connect(Socket.java:589)

         at java.net.Socket.connect(Socket.java:538)

         at sun.net.NetworkClient.doConnect(NetworkClient.java:180)

         at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)

         at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)

         at sun.net.www.http.HttpClient.<init>(HttpClient.java:211)

         at sun.net.www.http.HttpClient.New(HttpClient.java:308)

         at sun.net.www.http.HttpClient.New(HttpClient.java:326)

         at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1202)

         at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1138)

         at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1032)

         at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:966)

         at sun.net.www.protocol.http.HttpURLConnection.getOutputStream0(HttpURLConnection.java:1316)

         at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1291)

         at kd.isc.iscb.util.misc.NetUtil.sendRequest(NetUtil.java:403)

         at kd.isc.iscb.util.misc.NetUtil.httpInvoke(NetUtil.java:291)

         at kd.isc.iscb.util.misc.NetUtil.asyncHttpInvoke(NetUtil.java:164)

         ... 40 more

问题分析：请查看异常信息中的url地址所访问的服务器是否配置了防火墙策略（例如禁止短时间内多次访问或流量控制），请调整防火墙策略，把苍穹ip加入到防火墙白名单中，不要策略拦截或拒绝访问。