[HBASE-22860] Master's webui returns NPE/HTTP 500 under maintenance mode

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha-1, 2.2.0, 2.1.5, 2.2.1, 2.1.6
• Fix Version/s: 3.0.0-alpha-1, 2.2.1, 2.1.6
• Component/s: master, UI
• Assignee: Daisuke Kobayashi
• Reporter: Daisuke Kobayashi
• Created: 15/Aug/19 07:08
• Updated: 17/Aug/19 00:37
• Resolved: 16/Aug/19 10:55

Description

Master's webui is not accessible when hbase.master.maintenance_mode is set to true. This is because it's trying to load a coprocessor RSGroupAdminEndpoint.

java.lang.NullPointerException
	at org.apache.hadoop.hbase.tmpl.master.MasterStatusTmplImpl.renderNoFlush(MasterStatusTmplImpl.java:326)
	at org.apache.hadoop.hbase.tmpl.master.MasterStatusTmpl.renderNoFlush(MasterStatusTmpl.java:397)
	at org.apache.hadoop.hbase.tmpl.master.MasterStatusTmpl.render(MasterStatusTmpl.java:388)
	at org.apache.hadoop.hbase.master.MasterStatusServlet.doGet(MasterStatusServlet.java:81)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:848)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1780)
	at org.apache.hadoop.hbase.http.lib.StaticUserWebFilter$StaticUserFilter.doFilter(StaticUserWebFilter.java:112)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.ClickjackingPreventionFilter.doFilter(ClickjackingPreventionFilter.java:48)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.HttpServer$QuotingInputFilter.doFilter(HttpServer.java:1374)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.NoCacheFilter.doFilter(NoCacheFilter.java:49)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.NoCacheFilter.doFilter(NoCacheFilter.java:49)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:583)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1180)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:513)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1112)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:119)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:134)
	at org.eclipse.jetty.server.Server.handle(Server.java:539)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:333)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:251)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:283)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:108)
	at org.eclipse.jetty.io.SelectChannelEndPoint$2.run(SelectChannelEndPoint.java:93)
	at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.executeProduceConsume(ExecuteProduceConsume.java:303)
	at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceConsume(ExecuteProduceConsume.java:148)
	at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:136)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:671)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:589)
	at java.lang.Thread.run(Thread.java:748)