Cross Data Center Replication for existing Indexes

Hi all,

After several attempts I am unable to get CDCR working for a solr core with existing documents.

My first attempt failed due to incompatibility with the tlog file names,

Caused by: java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1967)
at org.apache.solr.update.CdcrUpdateLog.getLastLogId(CdcrUpdateLog.java:154)
at org.apache.solr.update.UpdateLog.init(UpdateLog.java:282)
at org.apache.solr.update.CdcrUpdateLog.init(CdcrUpdateLog.java:77)
at org.apache.solr.update.UpdateHandler.<init>(UpdateHandler.java:137)

This is going from having an update handler of
<updateLog>
<str name="dir">/somedir/</str>
</updateLog>

to
<updateLog class="solr.CdcrUpdateLog">
<str name="dir">/somedir</str>
</updateLog>

I believe this is due to the file patterns differing for the default update log class and the CdcrUpdateLog class.

I then continued to follow https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=62687462#CrossDataCenterReplication(CDCR)-FirstTime

which does not describe having the CdcrUpdateLog class, to which solr will now start erroring with

Caused by: org.apache.solr.common.SolrException: Solr instance is not configured with the cdcr update log.
at org.apache.solr.core.SolrCore.<init>(SolrCore.java:771)
at org.apache.solr.core.SolrCore.<init>(SolrCore.java:642)
at org.apache.solr.core.CoreContainer.create(CoreContainer.java:817)
at org.apache.solr.core.CoreContainer.access$000(CoreContainer.java:88)
at org.apache.solr.core.CoreContainer$1.call(CoreContainer.java:468)
at org.apache.solr.core.CoreContainer$1.call(CoreContainer.java:459)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.apache.solr.common.util.ExecutorUtil$MDCAwareThreadPoolExecutor.lambda$execute$0(ExecutorUtil.java:229)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
... 1 more
Caused by: org.apache.solr.common.SolrException: Solr instance is not configured with the cdcr update log.
at org.apache.solr.handler.CdcrRequestHandler.inform(CdcrRequestHandler.java:223)
at org.apache.solr.core.SolrResourceLoader.inform(SolrResourceLoader.java:675)
at org.apache.solr.core.SolrCore.<init>(SolrCore.java:751)
... 10 more

I may have completely missunderstood but please advise?

Thanks

Mike