Hi All,
We are using Solr 5.2.1 in a production environment where we have a high volume
of requests. We are not having any timeouts or performance issues. However, the
logs are filled with this exception.
We've been researching and there isn't a lot of information about this problem
or why it happens. We have tried to reproduce it by sending queries using
JMeter and it only happens when multiple queries are sent at the same time.
Checking the code we found that this exception is within the core Solr code and
part of the exception caught our attention as it is logging debug information
(we are using INFO logging level)
(org.apache.solr.search.stats.LocalStatsCache.get(LocalStatsCache.java:40)).
Has anyone seen this exception before? Would it be OK to generate a patch? We
were thinking about commenting the debug line or adding try/catch statements.
Thank you!
null:java.util.ConcurrentModificationException
at
java.util.LinkedHashMap$LinkedHashIterator.nextEntry(LinkedHashMap.java:394)
at java.util.LinkedHashMap$EntryIterator.next(LinkedHashMap.java:413)
at java.util.LinkedHashMap$EntryIterator.next(LinkedHashMap.java:412)
at
org.apache.solr.common.params.ModifiableSolrParams.toString(ModifiableSolrParams.java:201)
at java.lang.String.valueOf(String.java:2849)
at java.lang.StringBuilder.append(StringBuilder.java:128)
at
org.apache.solr.request.SolrQueryRequestBase.toString(SolrQueryRequestBase.java:165)
at
org.apache.solr.search.stats.LocalStatsCache.get(LocalStatsCache.java:40)
at
org.apache.solr.handler.component.QueryComponent.process(QueryComponent.java:366)
at
org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:255)
at
org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:143)
at org.apache.solr.core.SolrCore.execute(SolrCore.java:2064)
at org.apache.solr.servlet.HttpSolrCall.execute(HttpSolrCall.java:654)
at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:450)
at
org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:227)
at
org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:196)
at
org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at
org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
at
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at
org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)
at
org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
at
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at
org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at
org.eclipse.jetty.server.handler.RequestLogHandler.handle(RequestLogHandler.java:95)
at
org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1129)
at
org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
at
org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at
org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
at
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at
org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215)
at
org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
at
org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:497)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:310)
at
org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)
at
org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540)
at
org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
at
org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
at java.lang.Thread.run(Thread.java:745)
KATHERINE MORA
Senior Engineer
