ReadTimeout on commit

[spring]

Hi,

I'm indexing documents in batches of 100 docs. Then commit.

Sometimes I get this exception:

org.apache.solr.client.solrj.SolrServerException:
java.net.SocketTimeoutException: Read timed out
        at
org.apache.solr.client.solrj.impl.CommonsHttpSolrServer.request(CommonsHttpS
olrServer.java:475)
        at
org.apache.solr.client.solrj.impl.CommonsHttpSolrServer.request(CommonsHttpS
olrServer.java:249)
        at
org.apache.solr.client.solrj.request.AbstractUpdateRequest.process(AbstractU
pdateRequest.java:105)
        at
org.apache.solr.client.solrj.SolrServer.commit(SolrServer.java:178)


I found some similar postings in the web, all recommending autocommit. This
is unfortunately not an option for me, because I have to know whether solr
committed or not.

What is causing this timeout?

I'm using these settings in solrj:

        server.setSoTimeout(1000);
          server.setConnectionTimeout(100);
          server.setDefaultMaxConnectionsPerHost(100);
          server.setMaxTotalConnections(100);
          server.setFollowRedirects(false);
          server.setAllowCompression(true);
          server.setMaxRetries(1);

Thank you