[SOLR-9861] Support Cross Data Center Replication under HDFS

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 6.3
• Component/s: CDCR, Hadoop Integration, hdfs
• Assignee: Unassigned
• Reporter: Gero Willmes
• Created: 13/Dec/16 10:02
• Updated: 28/Oct/20 20:37
• Resolved: 28/Oct/20 20:37

Description

Currently Solr Cloud does not support CDCR under HDFS (according to http://search-lucene.com/m/Solr/eHNlLSriaVCpuU1?subj=Re+Using+Solr+CDCR+with+HdfsDirectoryFactory).
If the CDCR configuration is performed according to

https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=62687462

and at the same time the HdfsDirectoryFactory is configured on both Source cluster and Target cluster according to

https://cwiki.apache.org/confluence/display/solr/Running+Solr+on+HDFS

it leads to the following error message during reload of the collection “collection_source” of the source cluster:

2016-11-23 12:05:35.604 ERROR (qtp1134712904-8045) [c:collection_source s:shard1 r:core_node1 x:collection_source_shard1_replica1] o.a.s.s.HttpSolrCall null:org.apache.solr.common.SolrException: Error handling 'reload' action
        at org.apache.solr.handler.admin.CoreAdminOperation$3.call(CoreAdminOperation.java:150)
        at org.apache.solr.handler.admin.CoreAdminHandler$CallInfo.call(CoreAdminHandler.java:367)
        at org.apache.solr.handler.admin.CoreAdminHandler.handleRequestBody(CoreAdminHandler.java:158)
        at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:156)
        at org.apache.solr.servlet.HttpSolrCall.handleAdminRequest(HttpSolrCall.java:663)
        at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:445)
        at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:257)
        at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:208)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1668)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:581)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
        at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1160)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:511)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1092)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:213)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:119)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:134)
        at org.eclipse.jetty.server.Server.handle(Server.java:518)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:308)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:244)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:273)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95)
        at org.eclipse.jetty.io.SelectChannelEndPoint$2.run(SelectChannelEndPoint.java:93)
        at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceAndRun(ExecuteProduceConsume.java:246)
        at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:156)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:654)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:572)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.solr.common.SolrException: Unable to reload core [collection_source_shard1_replica1]
        at org.apache.solr.core.CoreContainer.reload(CoreContainer.java:920)
        at org.apache.solr.handler.admin.CoreAdminOperation$3.call(CoreAdminOperation.java:148)
        ... 31 more
Caused by: org.apache.solr.common.SolrException: Solr instance is not configured with the cdcr update log.

However, the solr instance was configured correctly. CDCR should work in the same way with HdfsDirectoryFactory as it works with StandardDirectoryFactory or NRTCachingDirectoryFactory.