Thank you for the reply. Sorry I did not include more information in the first post.
So maybe there's some confusion here from my end. So both the target and source clusters are running in cloud mode. So I think you're correct that it is a different issue. So it looks like the source leader to target leader is successful but the target leader is then unsuccessful in replicating to its followers. The "unable to locate core" message is originally coming from the target cluster. *Here are the logs being generated from the source for reference:* 2019-02-02 20:10:19.551 INFO (cdcr-bootstrap-status-81-thread-1-processing-n:sourcehost001.com:30100_solr x:testcollection_shard3_replica_n10 c:testcollection s:shard3 r:core_node12) [c:testcollection s:shard3 r:core_node12 x:testcollection_shard3_replica_n10] o.a.s.h.CdcrReplicatorManager CDCR bootstrap successful in 3 seconds 2019-02-02 20:10:19.564 INFO (cdcr-bootstrap-status-81-thread-1-processing-n:sourcehost001.com:30100_solr x:testcollection_shard3_replica_n10 c:testcollection s:shard3 r:core_node12) [c:testcollection s:shard3 r:core_node12 x:testcollection_shard3_replica_n10] o.a.s.h.CdcrReplicatorManager Create new update log reader for target testcollection with checkpoint 1624389130873995265 @ testcollection:shard3 2019-02-02 20:10:19.568 ERROR (cdcr-bootstrap-status-81-thread-1-processing-n:sourcehost001.com:30100_solr x:testcollection_shard3_replica_n10 c:testcollection s:shard3 r:core_node12) [c:testcollection s:shard3 r:core_node12 x:testcollection_shard3_replica_n10] o.a.s.h.CdcrReplicatorManager Unable to bootstrap the target collection testcollection shard: shard3 org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException: Error from server at http://targethost001.com:30100/solr: Unable to locate core testcollection_shard2_replica_n4 at org.apache.solr.client.solrj.impl.HttpSolrClient.executeMethod(HttpSolrClient.java:643) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:255) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:244) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.LBHttpSolrClient.doRequest(LBHttpSolrClient.java:483) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.LBHttpSolrClient.request(LBHttpSolrClient.java:413) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.CloudSolrClient.sendRequest(CloudSolrClient.java:1107) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.CloudSolrClient.requestWithRetryOnStaleState(CloudSolrClient.java:884) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.CloudSolrClient.request(CloudSolrClient.java:817) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.SolrClient.request(SolrClient.java:1219) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.handler.CdcrReplicatorManager.sendRequestRecoveryToFollower(CdcrReplicatorManager.java:439) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at org.apache.solr.handler.CdcrReplicatorManager.sendRequestRecoveryToFollowers(CdcrReplicatorManager.java:428) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at org.apache.solr.handler.CdcrReplicatorManager.access$300(CdcrReplicatorManager.java:63) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at org.apache.solr.handler.CdcrReplicatorManager$BootstrapStatusRunnable.run(CdcrReplicatorManager.java:306) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_192] at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_192] at org.apache.solr.common.util.ExecutorUtil$MDCAwareThreadPoolExecutor.lambda$execute$0(ExecutorUtil.java:209) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_192] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_192] at java.lang.Thread.run(Thread.java:748) [?:1.8.0_192] 2019-02-02 20:10:19.602 INFO (cdcr-bootstrap-status-86-thread-1) [ ] o.a.s.h.CdcrReplicatorManager CDCR bootstrap successful in 3 seconds 2019-02-02 20:10:19.608 INFO (cdcr-bootstrap-status-86-thread-1) [ ] o.a.s.h.CdcrReplicatorManager Create new update log reader for target testcollection with checkpoint 1624389130873995265 @ testcollection:shard2 2019-02-02 20:10:19.610 ERROR (cdcr-bootstrap-status-86-thread-1) [ ] o.a.s.h.CdcrReplicatorManager Unable to bootstrap the target collection testcollection shard: shard2 org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException: Error from server at http://targethost001.com:30100/solr: Unable to locate core testcollection_shard2_replica_n4 at org.apache.solr.client.solrj.impl.HttpSolrClient.executeMethod(HttpSolrClient.java:643) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:255) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.HttpSolrClient.request(HttpSolrClient.java:244) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.LBHttpSolrClient.doRequest(LBHttpSolrClient.java:483) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.LBHttpSolrClient.request(LBHttpSolrClient.java:413) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.CloudSolrClient.sendRequest(CloudSolrClient.java:1107) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.CloudSolrClient.requestWithRetryOnStaleState(CloudSolrClient.java:884) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.impl.CloudSolrClient.request(CloudSolrClient.java:817) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.client.solrj.SolrClient.request(SolrClient.java:1219) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at org.apache.solr.handler.CdcrReplicatorManager.sendRequestRecoveryToFollower(CdcrReplicatorManager.java:439) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at org.apache.solr.handler.CdcrReplicatorManager.sendRequestRecoveryToFollowers(CdcrReplicatorManager.java:428) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at org.apache.solr.handler.CdcrReplicatorManager.access$300(CdcrReplicatorManager.java:63) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at org.apache.solr.handler.CdcrReplicatorManager$BootstrapStatusRunnable.run(CdcrReplicatorManager.java:306) ~[solr-core-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:55] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_192] at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_192] at org.apache.solr.common.util.ExecutorUtil$MDCAwareThreadPoolExecutor.lambda$execute$0(ExecutorUtil.java:209) ~[solr-solrj-7.5.0.jar:7.5.0 b5bf70b7e32d7ddd9742cc821d471c5fabd4e3df - jimczi - 2018-09-18 13:07:58] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_192] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_192] at java.lang.Thread.run(Thread.java:748) [?:1.8.0_192] * Here are the logs from the target:* 2019-02-02 20:10:19.566 INFO (qtp1571967156-14) [ x:testcollection_shard2_replica_n4] o.a.s.h.a.CoreAdminOperation It has been requested that we recover: core=testcollection_shard2_replica_n4 2019-02-02 20:10:19.567 ERROR (qtp1571967156-14) [ x:testcollection_shard2_replica_n4] o.a.s.h.RequestHandlerBase org.apache.solr.common.SolrException: Unable to locate core testcollection_shard2_replica_n4 at org.apache.solr.handler.admin.CoreAdminOperation.lambda$static$5(CoreAdminOperation.java:167) at org.apache.solr.handler.admin.CoreAdminOperation.execute(CoreAdminOperation.java:360) at org.apache.solr.handler.admin.CoreAdminHandler$CallInfo.call(CoreAdminHandler.java:395) at org.apache.solr.handler.admin.CoreAdminHandler.handleRequestBody(CoreAdminHandler.java:180) at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199) at org.apache.solr.servlet.HttpSolrCall.handleAdmin(HttpSolrCall.java:734) at org.apache.solr.servlet.HttpSolrCall.handleAdminRequest(HttpSolrCall.java:715) at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:496) at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:377) at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:323) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1634) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146) at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595) at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1317) at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564) at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1219) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144) at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:219) at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:335) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.server.Server.handle(Server.java:531) at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352) at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260) at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281) at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102) at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126) at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:762) at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:680) at java.lang.Thread.run(Thread.java:748) 2019-02-02 20:10:19.567 INFO (qtp1571967156-14) [ x:testcollection_shard2_replica_n4] o.a.s.s.HttpSolrCall [admin] webapp=null path=/admin/cores params={core=testcollection_shard2_replica_n4&action=REQUESTRECOVERY&wt=javabin&version=2} status=400 QTime=0 2019-02-02 20:10:19.607 INFO (qtp1571967156-133) [c:testcollection s:shard1 r:core_node5 x:testcollection_shard1_replica_n2] o.a.s.c.S.Request [testcollection_shard1_replica_n2] webapp=/solr path=/cdcr params={_stateVer_=testcollection:6&action=COLLECTIONCHECKPOINT&wt=javabin&version=2} status=0 QTime=4 2019-02-02 20:10:19.609 INFO (qtp1571967156-14) [ x:testcollection_shard2_replica_n4] o.a.s.h.a.CoreAdminOperation It has been requested that we recover: core=testcollection_shard2_replica_n4 2019-02-02 20:10:19.609 ERROR (qtp1571967156-14) [ x:testcollection_shard2_replica_n4] o.a.s.h.RequestHandlerBase org.apache.solr.common.SolrException: Unable to locate core testcollection_shard2_replica_n4 at org.apache.solr.handler.admin.CoreAdminOperation.lambda$static$5(CoreAdminOperation.java:167) at org.apache.solr.handler.admin.CoreAdminOperation.execute(CoreAdminOperation.java:360) at org.apache.solr.handler.admin.CoreAdminHandler$CallInfo.call(CoreAdminHandler.java:395) at org.apache.solr.handler.admin.CoreAdminHandler.handleRequestBody(CoreAdminHandler.java:180) at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199) at org.apache.solr.servlet.HttpSolrCall.handleAdmin(HttpSolrCall.java:734) at org.apache.solr.servlet.HttpSolrCall.handleAdminRequest(HttpSolrCall.java:715) at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:496) at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:377) at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:323) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1634) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146) at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595) at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1317) at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564) at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1219) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144) at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:219) at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:335) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.server.Server.handle(Server.java:531) at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352) at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260) at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281) at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102) at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126) at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:762) at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:680) at java.lang.Thread.run(Thread.java:748) 2019-02-02 20:10:19.609 INFO (qtp1571967156-14) [ x:testcollection_shard2_replica_n4] o.a.s.s.HttpSolrCall [admin] webapp=null path=/admin/cores params={core=testcollection_shard2_replica_n4&action=REQUESTRECOVERY&wt=javabin&version=2} status=400 QTime=0 2019-02-02 20:10:19.701 INFO (qtp1571967156-135) [ x:testcollection_shard2_replica_n4] o.a.s.h.a.CoreAdminOperation It has been requested that we recover: core=testcollection_shard2_replica_n4 2019-02-02 20:10:19.702 ERROR (qtp1571967156-135) [ x:testcollection_shard2_replica_n4] o.a.s.h.RequestHandlerBase org.apache.solr.common.SolrException: Unable to locate core testcollection_shard2_replica_n4 at org.apache.solr.handler.admin.CoreAdminOperation.lambda$static$5(CoreAdminOperation.java:167) at org.apache.solr.handler.admin.CoreAdminOperation.execute(CoreAdminOperation.java:360) at org.apache.solr.handler.admin.CoreAdminHandler$CallInfo.call(CoreAdminHandler.java:395) at org.apache.solr.handler.admin.CoreAdminHandler.handleRequestBody(CoreAdminHandler.java:180) at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199) at org.apache.solr.servlet.HttpSolrCall.handleAdmin(HttpSolrCall.java:734) at org.apache.solr.servlet.HttpSolrCall.handleAdminRequest(HttpSolrCall.java:715) at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:496) at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:377) at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:323) at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1634) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146) at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595) at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1317) at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564) at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1219) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144) at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:219) at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:335) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) at org.eclipse.jetty.server.Server.handle(Server.java:531) at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352) at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260) at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281) at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102) at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168) at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126) at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:762) at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:680) at java.lang.Thread.run(Thread.java:748) 2019-02-02 20:10:19.702 INFO (qtp1571967156-135) [ x:testcollection_shard2_replica_n4] o.a.s.s.HttpSolrCall [admin] webapp=null path=/admin/cores params={core=testcollection_shard2_replica_n4&action=REQUESTRECOVERY&wt=javabin&version=2} status=400 QTime=0 So the leader to leader replication is successful but the target leader is not able to replicate to the follower. So after some more investigation I found it's the call to recover the core that is having issues. When it makes the call to /solr/admin/cores?core=testcollection_shard2_replica_n4&action=REQUESTRECOVERY that is when it is unable to locate core. It's actually sending the call to the wrong host. So our setup is like the following: numShards: 3, replicationFact: 2, maxShards: 2. I wanted to retest it so I deleted and recreated the collection and the aftermath looked like the following: targetServer1s: s2r4 (shard 3, replica8), s3r10 targetServer2: s1,r1, s3r8, targetServer3: s2r6, s3r10 sourceServer1: s2r4, s3r10 sourceServer2: s1r2, s3r8 sourceServer3: s1r1, s2r6 When running CDCR once again the replication to the leaders was successful. The leaders for both were: s2r4, s3r10, s1r1. After CDCR, the source cluster made a call to recover s2r6. The source sent this call to targetServer1 which contained s2r4, and s3r10. As s2r6 is on targetServer3, the call was unsuccessful as it was not able to locate s2r6 on targetServer1. Unsure of a fix at this time. -- Sent from: http://lucene.472066.n3.nabble.com/Solr-User-f472068.html
