Thanks. This was helpful. I did some tcpdumps and I'm noticing that the requests to the target data center are not batched in any way. Each update comes in as an independent update. Some follow-up questions:
1. Is it accurate that updates are not actually batched in transit from the source to the target and instead each document is posted separately? 2. Are they done synchronously? I assume yes (since you wouldn't want operations applied out of order) 3. If they are done synchronously, and are not batched in any way, does that mean that the best performance I can expect would be roughly how long it takes to round-trip a single document? ie. If my average ping is 25ms, then I can expect a peak performance of roughly 40 ops/s. Thanks > On Mar 9, 2018, at 11:21 AM, Davis, Daniel (NIH/NLM) [C] > <daniel.da...@nih.gov> wrote: > > These are general guidelines, I've done loads of networking, but may be less > familiar with SolrCloud and CDCR architecture. However, I know it's all TCP > sockets, so general guidelines do apply. > > Check the round-trip time between the data centers using ping or TCP ping. > Throughput tests may be high, but if Solr has to wait for a response to a > request before sending the next action, then just like any network protocol > that does that, it will get slow. > > I'm pretty sure CDCR uses HTTP/HTTPS rather than just TCP, so also check > whether some proxy/load balancer between data centers is causing it to be a > single connection per operation. That will *kill* performance. Some > proxies default to HTTP/1.0 (open, send request, server send response, > close), and that will hurt. > > Why you should listen to me even without SolrCloud knowledge - checkout paper > "Latency performance of SOAP Implementations". Same distribution of skills > - I knew TCP well, but Apache Axis 1.1 not so well. I still improved > response time of Apache Axis 1.1 by 250ms per call with 1-line of code. > > -----Original Message----- > From: Tom Peters [mailto:tpet...@synacor.com] > Sent: Wednesday, March 7, 2018 6:19 PM > To: solr-user@lucene.apache.org > Subject: CDCR performance issues > > I'm having issues with the target collection staying up-to-date with indexing > from the source collection using CDCR. > > This is what I'm getting back in terms of OPS: > > curl -s 'solr2-a:8080/solr/mycollection/cdcr?action=OPS' | jq . > { > "responseHeader": { > "status": 0, > "QTime": 0 > }, > "operationsPerSecond": [ > "zook01,zook02,zook03/solr", > [ > "mycollection", > [ > "all", > 49.10140553500938, > "adds", > 10.27612635309587, > "deletes", > 38.82527896994054 > ] > ] > ] > } > > The source and target collections are in separate data centers. > > Doing a network test between the leader node in the source data center and > the ZooKeeper nodes in the target data center show decent enough network > performance: ~181 Mbit/s > > I've tried playing around with the "batchSize" value (128, 512, 728, 1000, > 2000, 2500) and they've haven't made much of a difference. > > Any suggestions on potential settings to tune to improve the performance? > > Thanks > > -- > > Here's some relevant log lines from the source data center's leader: > > 2018-03-07 23:16:11.984 INFO > (cdcr-replicator-207-thread-3-processing-n:solr2-a:8080_solr > x:mycollection_shard1_replica_n6 s:shard1 c:mycollection r:core_node9) > [c:mycollection s:shard1 r:core_node9 x:mycollection_shard1_replica_n6] > o.a.s.h.CdcrReplicator Forwarded 511 updates to target mycollection > 2018-03-07 23:16:23.062 INFO > (cdcr-replicator-207-thread-4-processing-n:solr2-a:8080_solr > x:mycollection_shard1_replica_n6 s:shard1 c:mycollection r:core_node9) > [c:mycollection s:shard1 r:core_node9 x:mycollection_shard1_replica_n6] > o.a.s.h.CdcrReplicator Forwarded 510 updates to target mycollection > 2018-03-07 23:16:32.063 INFO > (cdcr-replicator-207-thread-5-processing-n:solr2-a:8080_solr > x:mycollection_shard1_replica_n6 s:shard1 c:mycollection r:core_node9) > [c:mycollection s:shard1 r:core_node9 x:mycollection_shard1_replica_n6] > o.a.s.h.CdcrReplicator Forwarded 511 updates to target mycollection > 2018-03-07 23:16:36.209 INFO > (cdcr-replicator-207-thread-1-processing-n:solr2-a:8080_solr > x:mycollection_shard1_replica_n6 s:shard1 c:mycollection r:core_node9) > [c:mycollection s:shard1 r:core_node9 x:mycollection_shard1_replica_n6] > o.a.s.h.CdcrReplicator Forwarded 512 updates to target mycollection > 2018-03-07 23:16:42.091 INFO > (cdcr-replicator-207-thread-2-processing-n:solr2-a:8080_solr > x:mycollection_shard1_replica_n6 s:shard1 c:mycollection r:core_node9) > [c:mycollection s:shard1 r:core_node9 x:mycollection_shard1_replica_n6] > o.a.s.h.CdcrReplicator Forwarded 512 updates to target mycollection > 2018-03-07 23:16:46.790 INFO > (cdcr-replicator-207-thread-3-processing-n:solr2-a:8080_solr > x:mycollection_shard1_replica_n6 s:shard1 c:mycollection r:core_node9) > [c:mycollection s:shard1 r:core_node9 x:mycollection_shard1_replica_n6] > o.a.s.h.CdcrReplicator Forwarded 511 updates to target mycollection > 2018-03-07 23:16:50.004 INFO > (cdcr-replicator-207-thread-4-processing-n:solr2-a:8080_solr > x:mycollection_shard1_replica_n6 s:shard1 c:mycollection r:core_node9) > [c:mycollection s:shard1 r:core_node9 x:mycollection_shard1_replica_n6] > o.a.s.h.CdcrReplicator Forwarded 512 updates to target mycollection > > > And what the log looks like in the target: > > 2018-03-07 23:18:46.475 INFO (qtp1595212853-26) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067896487950&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.500 INFO (qtp1595212853-25) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067896487951&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.525 INFO (qtp1595212853-24) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536512&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.550 INFO (qtp1595212853-3793) [c:mycollection > s:shard1 r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536513&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.575 INFO (qtp1595212853-30) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536514&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.600 INFO (qtp1595212853-26) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536515&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.625 INFO (qtp1595212853-25) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536516&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.651 INFO (qtp1595212853-24) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536517&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.676 INFO (qtp1595212853-3793) [c:mycollection > s:shard1 r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536518&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > 2018-03-07 23:18:46.701 INFO (qtp1595212853-30) [c:mycollection s:shard1 > r:core_node2 x:mycollection_shard1_replica_n1] o.a.s.c.S.Request > [mycollection_shard1_replica_n1] webapp=/solr path=/update > params={_stateVer_=mycollection:30&_version_=-1594317067897536519&cdcr.update=&wt=javabin&version=2} > status=0 QTime=0 > > > > This message and any attachment may contain information that is confidential > and/or proprietary. Any use, disclosure, copying, storing, or distribution of > this e-mail or any attached file by anyone other than the intended recipient > is strictly prohibited. If you have received this message in error, please > notify the sender by reply email and delete the message and any attachments. > Thank you. This message and any attachment may contain information that is confidential and/or proprietary. Any use, disclosure, copying, storing, or distribution of this e-mail or any attached file by anyone other than the intended recipient is strictly prohibited. If you have received this message in error, please notify the sender by reply email and delete the message and any attachments. Thank you.
