Strange missing parameter error in TRA test

Having only seen this once in 6390 beasting runs on TimeRoutedAliasUpdateProcessorTest, this is pretty rare, but also quite strange since clearly most of the time the parameter is set so, it must be that it got wiped out somewhere either in concurrency or somehow something got GC'd that shouldn't have....

[junit4] 2> 147028 ERROR (qtp2033520237-777) [n:127.0.0.1:44743_solr c:myalias_2017-10-23 s:shard1 r:core_node2 x:myalias_2017-10-23_shard1_replica_n1] o.a.s.h.RequestHandlerBase org.apache.solr.common.SolrException: Routed alias has invalid properties: org.apache.solr.common. SolrException: Missing required parameter: router.name [junit4] 2> at org.apache.solr.update.processor.TimeRoutedAliasUpdateProcessor.<init>(TimeRoutedAliasUpdateProcessor.java:140) [junit4] 2> at org.apache.solr.update.processor.TimeRoutedAliasUpdateProcessor.wrap(TimeRoutedAliasUpdateProcessor.java:116) [junit4] 2> at org.apache.solr.update.processor.DistributedUpdateProcessorFactory.getInstance(DistributedUpdateProcessorFactory.java:53) [junit4] 2> at org.apache.solr.update.processor.UpdateRequestProcessorChain.createProcessor(UpdateRequestProcessorChain.java:219) [junit4] 2> at org.apache.solr.handler.ContentStreamHandlerBase.handleRequestBody(ContentStreamHandlerBase.java:54) [junit4] 2> at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199) [junit4] 2> at org.apache.solr.core.SolrCore.execute(SolrCore.java:2552) [junit4] 2> at org.apache.solr.servlet.HttpSolrCall.execute(HttpSolrCall.java:709) [junit4] 2> at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:515) [junit4] 2> at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:395) [junit4] 2> at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:341) [junit4] 2> at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610) [junit4] 2> at org.apache.solr.client.solrj.embedded.JettySolrRunner$DebugFilter.doFilter(JettySolrRunner.java:158) [junit4] 2> at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610) [junit4] 2> at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540) [junit4] 2> at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255) [junit4] 2> at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1588) [junit4] 2> at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255) [junit4] 2> at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345) [junit4] 2> at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203) [junit4] 2> at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480) [junit4] 2> at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1557) [junit4] 2> at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201) [junit4] 2> at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247) [junit4] 2> at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144) [junit4] 2> at org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:703) [junit4] 2> at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) [junit4] 2> at org.eclipse.jetty.server.Server.handle(Server.java:502) [junit4] 2> at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:364) [junit4] 2> at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260) [junit4] 2> at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305) [junit4] 2> at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103) [junit4] 2> at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118) [junit4] 2> at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765) [junit4] 2> at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683) [junit4] 2> at java.lang.Thread.run(Thread.java:748) [junit4] 2> Caused by: org.apache.solr.common.SolrException: Missing required parameter: router.name [junit4] 2> at org.apache.solr.common.params.RequiredSolrParams.get(RequiredSolrParams.java:48) [junit4] 2> at org.apache.solr.cloud.api.collections.TimeRoutedAlias.<init>(TimeRoutedAlias.java:140) [junit4] 2> at org.apache.solr.update.processor.TimeRoutedAliasUpdateProcessor.<init>(TimeRoutedAliasUpdateProcessor.java:138) [junit4] 2> ... 35 more [junit4] 2> in the test: [junit4] ERROR 17.3s | TimeRoutedAliasUpdateProcessorTest.test <<< [junit4] > Throwable #1: org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException: Error from server at http://127.0.0.1:44743/solr/myalias_2017-10-23_shard1_replica_n1: Routed alias has invalid properties: org.apache.solr.common.SolrException: Missing required parameter: router.name [junit4] > at __randomizedtesting.SeedInfo.seed([DFCBE9B9B61E31C3:579FD66318E25C3B]:0) [junit4] > at org.apache.solr.client.solrj.impl.HttpSolrClient.executeMethod(HttpSolrClient.java:643) [junit4] > at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:255) [junit4] > at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:244) [junit4] > at org.apache.solr.client.solrj.impl.LBHttpSolrClient.doRequest(LBHttpSolrClient.java:484) [junit4] > at org.apache.solr.client.solrj.impl.LBHttpSolrClient.request(LBHttpSolrClient.java:414) [junit4] > at org.apache.solr.client.solrj.impl.CloudSolrClient.directUpdate(CloudSolrClient.java:561) [junit4] > at org.apache.solr.client.solrj.impl.CloudSolrClient.sendRequest(CloudSolrClient.java:1019) [junit4] > at org.apache.solr.client.solrj.impl.CloudSolrClient.requestWithRetryOnStaleState(CloudSolrClient.java:884) [junit4] > at org.apache.solr.client.solrj.impl.CloudSolrClient.request(CloudSolrClient.java:817) [junit4] > at org.apache.solr.client.solrj.SolrRequest.process(SolrRequest.java:194) [junit4] > at org.apache.solr.client.solrj.SolrClient.add(SolrClient.java:177) [junit4] > at org.apache.solr.client.solrj.SolrClient.add(SolrClient.java:138) [junit4] > at org.apache.solr.update.processor.TimeRoutedAliasUpdateProcessorTest.test(TimeRoutedAliasUpdateProcessorTest.java:150) [junit4] > at java.lang.Thread.run(Thread.java:748)