[SOLR-12057] CDCR does not replicate to Collections with TLOG Replicas

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 7.2
• Component/s: CDCR
• Assignee: Varun Thacker
• Reporter: Webster Homer
• Created: 05/Mar/18 16:53
• Updated: 28/Oct/20 20:37
• Resolved: 28/Oct/20 20:37

Description

We created a collection using TLOG replicas in our QA clouds.
We have a locally hosted solrcloud with 2 nodes, all our collections have 2 shards. We use CDCR to replicate the collections from this environment to 2 data centers hosted in Google cloud. This seems to work fairly well for our collections with NRT replicas. However the new TLOG collection has problems.
 
The google cloud solrclusters have 4 nodes each (3 separate Zookeepers). 2 shards per collection with 2 replicas per shard.
 
We never see data show up in the cloud collections, but we do see tlog files show up on the cloud servers. I can see that all of the servers have cdcr started, buffers are disabled.
The cdcr source configuration is:
 
"requestHandler":{"/cdcr":{
      "name":"/cdcr",
      "class":"solr.CdcrRequestHandler",
      "replica":[
       

{           "zkHost":"[xxx-mzk01.sial.com:2181|http://xxx-mzk01.sial.com:2181/],[xxx-mzk02.sial.com:2181|http://xxx-mzk02.sial.com:2181/],[xxx-mzk03.sial.com:2181/solr|http://xxx-mzk03.sial.com:2181/solr]",           "source":"b2b-catalog-material-180124T",           "target":"b2b-catalog-material-180124T"}

,
       

{           "zkHost":"[yyyy-mzk01.sial.com:2181|http://yyyy-mzk01.sial.com:2181/],[yyyy-mzk02.sial.com:2181|http://yyyy-mzk02.sial.com:2181/],[yyyy-mzk03.sial.com:2181/solr|http://yyyy-mzk03.sial.com:2181/solr]",           "source":"b2b-catalog-material-180124T",           "target":"b2b-catalog-material-180124T"}

],
      "replicator":

{         "threadPoolSize":4,         "schedule":500,         "batchSize":250}

,
      "updateLogSynchronizer":{"schedule":60000}}}}
 
The target configurations in the 2 clouds are the same:
"requestHandler":{"/cdcr":{ "name":"/cdcr", "class":"solr.CdcrRequestHandler", "buffer":

{"defaultState":"disabled"}

}} 
 
All of our collections have a timestamp field, index_date. In the source collection all the records have a date of 2/28/2018 but the target collections have a latest date of 1/26/2018
 
I don't see cdcr errors in the logs, but we use logstash to search them, and we're still perfecting that. 
 
We have a number of similar collections that behave correctly. This is the only collection that is a TLOG collection. It appears that CDCR doesn't support TLOG collections.
 
It looks like the data is getting to the target servers. I see tlog files with the right timestamps. Looking at the timestamps on the documents in the collection none of the data appears to have been loaded.In the solr.log I see lots of /cdcr messages  action=LASTPROCESSEDVERSION,  action=COLLECTIONCHECKPOINT, and  action=SHARDCHECKPOINT 
 
no errors
 
Target collections autoCommit is set to  60000 I tried sending a commit explicitly no difference. cdcr is uploading data, but no new data appears in the collection.