RM can not renew TIMELINE_DELEGATION_TOKEN in secure clusters

bin hadoop 2.7.1
ATS conf like this:
<property>
<name>yarn.timeline-service.http-authentication.type</name>
<value>simple</value>
</property>
<property>
<name>yarn.timeline-service.http-authentication.kerberos.principal</name>
<value>HTTP/_HOST@xxx.COM</value>
</property>
<property>
<name>yarn.timeline-service.http-authentication.kerberos.keytab</name>
<value>/etc/hadoop/keytabs/xxx.keytab</value>
</property>

<property>
<name>yarn.timeline-service.principal</name>
<value>xxx/_HOST@xxx.COM</value>
</property>
<property>
<name>yarn.timeline-service.keytab</name>
<value>/etc/hadoop/keytabs/xxx.keytab</value>
</property>

<property>
<name>yarn.timeline-service.best-effort</name>
<value>true</value>
</property>
<property>
<name>yarn.timeline-service.enabled</name>
<value>true</value>
</property>
<property>

I'd like to allow everyone to access ATS from HTTP as RM,HDFS.
client can submit job to RM and add TIMELINE_DELEGATION_TOKEN to AM Context, but RM can not renew TIMELINE_DELEGATION_TOKEN and make application to failure.
RM logs:
2015-11-03 11:58:38,191 WARN org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer: Unable to add the application to the delegation token renewer.
java.io.IOException: Failed to renew token: Kind: TIMELINE_DELEGATION_TOKEN, Service: 10.12.38.4:8188, Ident: (owner=yarn-test, renewer=yarn-test, realUser=, issueDate=1446523118046, maxDate=1447127918046, sequenceNumber=9, masterKeyId=2)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer.handleAppSubmitEvent(DelegationTokenRenewer.java:439)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer.access$700(DelegationTokenRenewer.java:78)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer$DelegationTokenRenewerRunnable.handleDTRenewerAppSubmitEvent(DelegationTokenRenewer.java:847)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer$DelegationTokenRenewerRunnable.run(DelegationTokenRenewer.java:828)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: HTTP status [500], message [Null user]
at org.apache.hadoop.util.HttpExceptionUtils.validateResponse(HttpExceptionUtils.java:169)
at org.apache.hadoop.security.token.delegation.web.DelegationTokenAuthenticator.doDelegationTokenOperation(DelegationTokenAuthenticator.java:287)
at org.apache.hadoop.security.token.delegation.web.DelegationTokenAuthenticator.renewDelegationToken(DelegationTokenAuthenticator.java:212)
at org.apache.hadoop.security.token.delegation.web.DelegationTokenAuthenticatedURL.renewDelegationToken(DelegationTokenAuthenticatedURL.java:414)
at org.apache.hadoop.yarn.client.api.impl.TimelineClientImpl$3.run(TimelineClientImpl.java:396)
at org.apache.hadoop.yarn.client.api.impl.TimelineClientImpl$3.run(TimelineClientImpl.java:378)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
at org.apache.hadoop.yarn.client.api.impl.TimelineClientImpl$5.run(TimelineClientImpl.java:451)
at org.apache.hadoop.yarn.client.api.impl.TimelineClientImpl$TimelineClientConnectionRetry.retryOn(TimelineClientImpl.java:183)
at org.apache.hadoop.yarn.client.api.impl.TimelineClientImpl.operateDelegationToken(TimelineClientImpl.java:466)
at org.apache.hadoop.yarn.client.api.impl.TimelineClientImpl.renewDelegationToken(TimelineClientImpl.java:400)
at org.apache.hadoop.yarn.security.client.TimelineDelegationTokenIdentifier$Renewer.renew(TimelineDelegationTokenIdentifier.java:81)
at org.apache.hadoop.security.token.Token.renew(Token.java:377)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer$1.run(DelegationTokenRenewer.java:543)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer$1.run(DelegationTokenRenewer.java:540)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer.renewToken(DelegationTokenRenewer.java:538)
at org.apache.hadoop.yarn.server.resourcemanager.security.DelegationTokenRenewer.handleAppSubmitEvent(DelegationTokenRenewer.java:437)
... 6 more

ATS logs:
2015-11-03 14:47:45,407 INFO org.apache.hadoop.security.token.delegation.AbstractDelegationTokenSecretManager: Creating password for identifier: owner=yarn-test, renewer=yarn-test, realUser=, issueDate=1446533265407, maxDate=1447138065407, sequenceNumber=5, masterKeyId=2, currentKey: 2
2015-11-03 14:47:46,055 ERROR org.mortbay.log: /ws/v1/timeline/
java.lang.IllegalArgumentException: Null user
at org.apache.hadoop.security.UserGroupInformation.createRemoteUser(UserGroupInformation.java:1204)
at org.apache.hadoop.security.UserGroupInformation.createRemoteUser(UserGroupInformation.java:1191)
at org.apache.hadoop.security.token.delegation.web.DelegationTokenAuthenticationHandler.managementOperation(DelegationTokenAuthenticationHandler.java:193)
at org.apache.hadoop.security.authentication.server.AuthenticationFilter.doFilter(AuthenticationFilter.java:514)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
at org.apache.hadoop.http.HttpServer2$QuotingInputFilter.doFilter(HttpServer2.java:1243)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
at org.apache.hadoop.http.NoCacheFilter.doFilter(NoCacheFilter.java:45)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
at org.apache.hadoop.http.NoCacheFilter.doFilter(NoCacheFilter.java:45)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

if change yarn.timeline-service.http-authentication.type to kerberos, all is ok,but ATS can not be accessed by HTTP.