The lists are OK since they are modified only in the constructor. The map needs to be changed to a ConcurrentHashMap as you did in the patch.
On Mon, Jan 26, 2009 at 7:23 PM, Shalin Shekhar Mangar < shalinman...@gmail.com> wrote: > Wow, well spotted. TemplateString is not thread-safe but it is being used > concurrently by many cores due to the static instance. Apart from the cache > map, the lists will also need to be taken care of. > > Can you please open an issue and attach this patch? > > https://issues.apache.org/jira/browse/SOLR > > > On Mon, Jan 26, 2009 at 7:07 PM, Ryuuichi KUMAI <ryu.ku...@gmail.com>wrote: > >> Hello, >> >> I'm using Solr 1.3 and I have a problem with DataImportHandler. >> >> My environment: >> - Solr 1.3 >> - MySQL 5.1.30, Connector/J 5.1.6 >> - Linux 2.6.9 x86_64 (RHEL4) >> - Sun JDK 1.6.0_11 >> - Apache Tomcat 6.0.18 >> >> Our Solr server has multi core, and the schema in each core is the same. >> When delta-import is executed concurrently in two (or more) cores, the >> CPU resources are exhausted and making the index doesn't progress. Then >> no exceptions are generated. >> This problem doesn't occur when delta-import is executed in one core (not >> concurrent). Does anyone know how this is caused? >> >> To avoid this problem, I changed temporarily the code of TemplateString >> in DIH as follows, and it works. Though I don't understand details of >> the cause of this problem, I guess that the cache in static object of >> TemplateString is related with this. >> >> Index: TemplateString.java >> =================================================================== >> --- TemplateString.java (revision 729410) >> +++ TemplateString.java (working copy) >> @@ -17,9 +17,9 @@ >> package org.apache.solr.handler.dataimport; >> >> import java.util.ArrayList; >> -import java.util.HashMap; >> import java.util.List; >> -import java.util.Map; >> +import java.util.concurrent.ConcurrentHashMap; >> +import java.util.concurrent.ConcurrentMap; >> import java.util.regex.Matcher; >> import java.util.regex.Pattern; >> >> @@ -40,10 +40,10 @@ >> >> private List<String> pcs = new ArrayList<String>(); >> >> - private Map<String, TemplateString> cache; >> + private ConcurrentMap<String, TemplateString> cache; >> >> public TemplateString() { >> - cache = new HashMap<String, TemplateString>(); >> + cache = new ConcurrentHashMap<String, TemplateString>(); >> } >> >> private TemplateString(String s) { >> @@ -70,7 +70,9 @@ >> TemplateString ts = cache.get(string); >> if (ts == null) { >> ts = new TemplateString(string); >> - cache.put(string, ts); >> + TemplateString cachedTs = cache.putIfAbsent(string, ts); >> + if (cachedTs != null) >> + ts = cachedTs; >> } >> return ts.fillTokens(resolver); >> } >> >> Does anyone has a better idea? >> I appreciate any help anyone can give me. >> >> Regards, >> Ryuuichi Kumai. >> > > > > -- > Regards, > Shalin Shekhar Mangar. > -- Regards, Shalin Shekhar Mangar.
