[SOLR-14484] NPE in ConcurrentUpdateHttp2SolrClient MDC logging

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 8.4.1
• Fix Version/s: 8.6
• Assignee: David Smiley
• Reporter: Andras Salamon
• Created: 14/May/20 08:26
• Updated: 15/Jul/20 15:11
• Resolved: 20/May/20 13:47

Description

client.getBaseURL() can be null in ConcurrentUpdateHttp2SolrClient which can cause problems in MDC logging.

We had the following error in the stacktrace. We were using Solr 8.4.1 from lily hbase-indexer which still uses log4j 1.2:

Error from server at http://127.0.0.1:45895/solr/collection1: java.lang.NullPointerException
 at java.util.Hashtable.put(Hashtable.java:459)
 at org.apache.log4j.MDC.put0(MDC.java:150)
 at org.apache.log4j.MDC.put(MDC.java:85)
 at org.slf4j.impl.Log4jMDCAdapter.put(Log4jMDCAdapter.java:67)
 at org.slf4j.MDC.put(MDC.java:147)
 at org.apache.solr.client.solrj.impl.ConcurrentUpdateHttp2SolrClient.addRunner(ConcurrentUpdateHttp2SolrClient.java:346)
 at org.apache.solr.client.solrj.impl.ConcurrentUpdateHttp2SolrClient.waitForEmptyQueue(ConcurrentUpdateHttp2SolrClient.java:565)