Migrate Cloudera solr 4.10.3-cdh-5.9.3 rto Apache solrcloud

[#1]

Hello,

        We are trying to migrate the data from Cloudera solr 4.10.3  to plain apache Solr cloud.

        We didn't find any proper document to migrate seamlessly.

        Anyone can provide clear documentation on the migration or suggest us the process to follow for the migration.

Thanks & Regards,

J. Ganesh Kumar.

[#2]

Hi, can you please give more info about the migration? 

Are you upgrading from HDP/CDH to CDP? 

Or this is only a Solr upgrade? In case it is, in which platform are you? HDP, CDP, CDH. 

[#3]

Hi,

      Due to some reason, We are planning to migration solr alone from cloudera search to plain solrcloud 4.10.3 (installed 3 solr and 3 zookeeper alone in baremetal).

     We are struggling in the migration process. We tried to create/test with one solr collection with same replicas and same no of shards in the plain solrcloud 4.10.3 and copied index data of corresponding shards/replicas to the plain solrcloud 4.10.3

   We got with the below error. we were surprised by the below error. because we used same version as we have in Cloudera Search

Caused by: org.apache.lucene.index.IndexFormatTooNewException: Format version is not supported (resource: BufferedChecksumIndex
Input(MMapIndexInput(path="/opt/solr-4.10.3/node1/solr/sample_collection_shard1_replica3/data/index.20190911092017197/segm
ents_4g8h"))): 4 (needs to be between 0 and 3)

Thanks & Regards,

J. Ganesh Kumar.

[#4 · Accepted solution]

Hello @ganeshkumarj 

Thanks for using Cloudera Community. Based on the Post, You are migrating from Cloudera Search (CDH 5.9.3) to Standalone Solr (Apache v4.10.3). As your Team mentioned, the Error points to Index (Copied manually) being on a Lucene Version higher than anticipated [1]. 

Your Team can confirm the LuceneVersion via "solrconfig.xml" for the Collection "sample_collection" on CDH. If LuceneVersion Match isn't feasible, ReIndexing is the Only Way forward. Yet, there are few things wherein our help in this Post would be limited:

(I) CDH v5.9.3 is EoS since a long time. Internally, We have extremely limited Setup for checking further on your Team's concerns. 

(II) Your Team is implementing the Migration on Standalone Solr (Apache v4.10.3). Cloudera Product Offering package Solr into Search (In CDH) & Solr (In CDP). Unfortunately, We have limited input on any Open Source Implementation outside of Cloudera Product. 

Our Team would be happy to assist your Team to Migrate from CDH v5.9.3 to CDP, if required by your Team. We have Documentation (Which are Tested internally) to migrate from CDH Search to CDP Solr & your Team would get the Support assistance in any issues as well. 

Regards, Smarak

[1] https://lucene.apache.org/core/7_1_0/core/org/apache/lucene/index/IndexFormatTooNewException.html