Solr
  1. Solr
  2. SOLR-4227

StreamingUpdateSolrServer does not buffer OutputStreamWriter with BufferedWriter, causing encoding explosion

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 3.2
    • Fix Version/s: 4.7, Trunk
    • Component/s: None
    • Labels:
      None
    • Environment:

      Java 1.6, Linux. I am running SOLR 3.2, but the code doesn't seem different in 3.5.

      Description

      org.apache.solr.client.solrj.impl.StreamingUpdateSolrServer line 112 is:
      OutputStreamWriter writer = new OutputStreamWriter(out, "UTF-8");
      and then we call
      req.writeXML( writer );
      Because the writer is not buffered, this causes the XML writer to call the UTF-8 encoder for each atom being written, like in org.apache.solr.common.util.XML.writeXML:
      out.write('<');
      This causes the stream encoder to allocate a char array to hold it, and
      sun.nio.cs.StreamEncoder.implWrite allocates a CharBuffer to wrap it. All just for one character.

      This is particularly a problem when you have a lot of threads (100?) writing to the SOLR server, they rapidly eat up all the CPU.

      It would be helpful to allocate the writer as a BufferedWriter, so encoding only happens when you flush. JavaDoc for OutputStreamWriter recommends this: "For top efficiency, consider wrapping an OutputStreamWriter within a BufferedWriter so as to avoid frequent converter invocations."

      1. SOLR-4227.patch
        0.8 kB
        Shalin Shekhar Mangar

        Activity

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          People

          • Assignee:
            Shalin Shekhar Mangar
            Reporter:
            Conrad Herrmann
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            Dates

            • Created:
              Updated:
              Resolved:

              Development