WSO2 DAS + Clustering APIM with mysql

My APIM version is 1.10.0 and DAS is 3.0.1.
At first ,I deploy no Clustering APIM + DAS with mysql. the stats shows good.
Then,I clustering APIM into publisher、store、keymanager and gateway.Configured APIM and DAS order this article,when I invoke an api , gateway node then show error

[2016-10-13 11:13:54,775] ERROR - APIMgtUsageHandler Cannot publish event. null
java.lang.NullPointerException
        at org.wso2.carbon.apimgt.usage.publisher.APIMgtUsageDataBridgeDataPublisher.publishEvent(APIMgtUsageDataBridgeDataPublisher.java:124)
        at org.wso2.carbon.apimgt.usage.publisher.APIMgtUsageHandler.handleRequest(APIMgtUsageHandler.java:169)
        at org.apache.synapse.rest.API.process(API.java:322)
        at org.apache.synapse.rest.RESTRequestHandler.dispatchToAPI(RESTRequestHandler.java:86)
        at org.apache.synapse.rest.RESTRequestHandler.process(RESTRequestHandler.java:65)
        at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:295)
        at org.apache.synapse.core.axis2.SynapseMessageReceiver.receive(SynapseMessageReceiver.java:83)
        at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
        at org.apache.synapse.transport.passthru.ServerWorker.processNonEntityEnclosingRESTHandler(ServerWorker.java:317)
        at org.apache.synapse.transport.passthru.ServerWorker.run(ServerWorker.java:149)
        at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
[2016-10-13 11:13:54,807] ERROR - APIMgtResponseHandler Cannot publish response event. null
java.lang.NullPointerException
        at org.wso2.carbon.apimgt.usage.publisher.APIMgtUsageDataBridgeDataPublisher.publishEvent(APIMgtUsageDataBridgeDataPublisher.java:140)
        at org.wso2.carbon.apimgt.usage.publisher.APIMgtResponseHandler.mediate(APIMgtResponseHandler.java:211)
        at org.apache.synapse.mediators.ext.ClassMediator.mediate(ClassMediator.java:84)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:81)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:48)
        at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:155)
        at org.apache.synapse.rest.Resource.process(Resource.java:297)
        at org.apache.synapse.rest.API.process(API.java:335)
        at org.apache.synapse.rest.RESTRequestHandler.dispatchToAPI(RESTRequestHandler.java:86)
        at org.apache.synapse.rest.RESTRequestHandler.process(RESTRequestHandler.java:52)
        at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:295)
        at org.apache.synapse.core.axis2.SynapseCallbackReceiver.handleMessage(SynapseCallbackReceiver.java:529)
        at org.apache.synapse.core.axis2.SynapseCallbackReceiver.receive(SynapseCallbackReceiver.java:172)
        at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
        at org.apache.synapse.transport.passthru.ClientWorker.run(ClientWorker.java:251)
        at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)

Then i change the way of DAS configuration. Following this blog ,i configured all the api-manager.xml,there is no error and no stats.And store node show info:

[2016-10-18 11:31:39,131]  INFO - ReceiverGroup Resending the failed published data...
[2016-10-18 11:31:44,134]  WARN - AccessConfiguration Error loading properties from file: access-log.properties
[2016-10-18 11:31:44,207]  INFO - TimeoutHandler This engine will expire all callbacks after : 120 seconds, irrespective of the timeout

I google the reason ,in wso2 jira,they say this is not a bug.

But I cannot wait for my stats for hours.Did I configure something wrong?

Reguards.

Seems in store node, data are publishing are enabled and working. But gateway node data not publishing. Please try to verify the gateway node configuration. Also check gateway node can access the DAS node.