Bug: NPE from /procedures.jsp on backup master
Status: Open | Priority: Major | Resolution: 
Created: 04/May/20 23:54
Affects Version/s: 2.3.0

When going to {{/procedures.jsp}} on a backup master (i.e., a user hits refresh on a window they have open, meanwhile, the active master has flipped over), we throw an NPE back to the user. Instead, we should do practically anything else.

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java.lang.NullPointerException
	at org.apache.hadoop.hbase.generated.master.procedures_jsp._jspService(procedures_jsp.java:63)
	at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:840)
	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$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.SecurityHeadersFilter.doFilter(SecurityHeadersFilter.java:66)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.ClickjackingPreventionFilter.doFilter(ClickjackingPreventionFilter.java:52)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.HttpServer$QuotingInputFilter.doFilter(HttpServer.java:1491)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1767)
	at org.apache.hadoop.hbase.http.NoCacheFilter.doFilter(NoCacheFilter.java:50)
	at org.eclipse.jetty.servlet.ServletHandler$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.base/java.lang.Thread.run(Thread.java:834)
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