Question

我们有一个包含3个节点的1个Kaa（0.9版）群集。我们发现端点有时会重新连接到Kaa节点并且无法获得任何通知。端点已订阅所有主题，我们也在管理网站中确认。在它连接到Kaa后，控制台只显示以下消息：

[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - KaaSync message (zipped=false, encrypted=true) received for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.DefaultOperationDataProcessor - Received Sync response: {"requestId": 2, "status": "SUCCESS", "bootstrapSyncResponse": null, "profileSyncResponse": null, "configurationSyncResponse": null, "notificationSyncResponse": {"responseStatus": "NO_DELTA", "notifications": [], "availableTopics": null}, "userSyncResponse": {"userAttachResponse": null, "userAttachNotification": null, "userDetachNotification": null, "endpointAttachResponses": [], "endpointDetachResponses": []}, "eventSyncResponse": {"eventSequenceNumberResponse": null, "eventListenersResponses": [], "events": null}, "redirectSyncResponse": null, "logSyncResponse": null, "extensionSyncResponses": null}
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.transports.DefaultNotificationTransport - Processed notification response.
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.transports.DefaultUserTransport - Processed user response
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Channel [default_operation_tcp_channel] is reading data from stream using [1024] byte buffer
[pool-6-thread-2] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Executing ping task for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - PingResponse message received for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Channel [default_operation_tcp_channel] is reading data from stream using [1024] byte buffer
[pool-6-thread-2] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Executing ping task for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - PingResponse message received for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Channel [default_operation_tcp_channel] is reading data from stream using [1024] byte buffer
[pool-6-thread-2] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Executing ping task for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - PingResponse message received for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Channel [default_operation_tcp_channel] is reading data from stream using [1024] byte buffer
[pool-6-thread-2] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Executing ping task for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - PingResponse message received for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Channel [default_operation_tcp_channel] is reading data from stream using [1024] byte buffer
[pool-6-thread-2] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - Executing ping task for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.channel.impl.channels.DefaultOperationTcpChannel - PingResponse message received for channel [default_operation_tcp_channel]
[pool-6-thread-1] INFO org.kaaproject.kaa.client.cnhannel.impl.channels.DefaultOperationTcpChannel - Channel [default_operation_tcp_channel] is reading data from stream using [1024] byte buffer

然后，我们尝试停止端点并再次重新连接到Kaa服务器。连接到Kaa后，将显示旧通知。但是，我们尝试向此端点发送新通知，但仍然无法获得新通知。

我们还发现如果我们断开与Kaa服务器的连接并重新连接它，我们可以再次收到通知。但是，端点无法获得通知条件似乎仍然发生在其他端点。我们不确定此问题是否与我们的群集有关。有时，我们将重新启动kaa-node服务，端点将在那时连接到其他2台服务器。

Answer 1

我们似乎找到了根本原因。从日志中，我们看到通知应该成功发送到端点。但是，似乎性能非常糟糕，端点需要大量时间来获取通知。最后，我们发现根本原因应该是我们服务器的交换文件。我们的服务器之前设置了交换文件，它似乎影响了发送通知的性能。我们尝试禁用交换空间并发送通知，端点可以在合理的时间内获得。

我们设置交换原因我们发现Kaa-node的内存使用量将在一天前超过我们服务器的80％。目前，我们尝试使用不同的java gc来替换原始的G1 gc，同时启动Kaa-node。内存使用似乎比使用G1 gc更好。我们将继续监控它。

重新连接到Kaa服务器后无法收到通知

1 个答案: