Solr
  1. Solr
  2. SOLR-91

warming searchers can stack up

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 1.1.0
    • Fix Version/s: 1.2
    • Component/s: None
    • Labels:
      None

      Description

      If the commit frequency is high, and searcher warming configured, sometimes an overlap of warming searchers can occur. Solr currently detects this and logs a warning message.

      While normally relatively harmless, multiple warming searchers can sometimes cause thrashing, extending the time it takes to complete warming, and causing a chain reaction where more and more searchers try to warm concurrently.

        Activity

        Hide
        Yonik Seeley added a comment -

        A bad solution would be to kill the oldest searcher... this strategy could lead to starvation.
        A better solution: allow a <commit/> to fail after a configurable threshold of the number of warming searchers is reached.

        Downsides:

        • commit currently does not fail (unless exceptional circumstances like an IOError)
        • If enabled on a master, two different clients doing a quick add+commit
          could now cause failure. We could either just recommend it never be enabled for a master, or
          some autocommit functionality could be added to enforce a minimum wait time between commits.
        Show
        Yonik Seeley added a comment - A bad solution would be to kill the oldest searcher... this strategy could lead to starvation. A better solution: allow a <commit/> to fail after a configurable threshold of the number of warming searchers is reached. Downsides: commit currently does not fail (unless exceptional circumstances like an IOError) If enabled on a master, two different clients doing a quick add+commit could now cause failure. We could either just recommend it never be enabled for a master, or some autocommit functionality could be added to enforce a minimum wait time between commits.
        Hide
        Yonik Seeley added a comment -

        OK, maxWarmingSearchers defines the max number of background warming searchers.

        Exceed it, and you get a 503 (which goes in the XML, not in the HTTP response code, but that's a different issue):

        $ curl http://localhost:8983/solr/update -i -d '<commit/>'
        HTTP/1.1 200 OK
        Date: Wed, 10 Jan 2007 01:05:41 GMT
        Server: Jetty/5.1.11RC0 (Windows XP/5.1 x86 java/1.5.0_09
        Content-Type: text/xml; charset=UTF-8
        Content-Length: 115

        <result status="503">Error opening new searcher. exceeded limit of maxWarmingSea
        rchers=2, try again later.</result>

        if missing in the config, the default is as before (unlimited).
        I set it to 4 in the example config as a happy medium between searchers and masters.

        Show
        Yonik Seeley added a comment - OK, maxWarmingSearchers defines the max number of background warming searchers. Exceed it, and you get a 503 (which goes in the XML, not in the HTTP response code, but that's a different issue): $ curl http://localhost:8983/solr/update -i -d '<commit/>' HTTP/1.1 200 OK Date: Wed, 10 Jan 2007 01:05:41 GMT Server: Jetty/5.1.11RC0 (Windows XP/5.1 x86 java/1.5.0_09 Content-Type: text/xml; charset=UTF-8 Content-Length: 115 <result status="503">Error opening new searcher. exceeded limit of maxWarmingSea rchers=2, try again later.</result> if missing in the config, the default is as before (unlimited). I set it to 4 in the example config as a happy medium between searchers and masters.
        Hide
        Yonik Seeley added a comment -

        committed.

        Show
        Yonik Seeley added a comment - committed.
        Hide
        Hoss Man added a comment -

        This bug was modified as part of a bulk update using the criteria...

        • Marked ("Resolved" or "Closed") and "Fixed"
        • Had no "Fix Version" versions
        • Was listed in the CHANGES.txt for 1.2

        The Fix Version for all 39 issues found was set to 1.2, email notification
        was suppressed to prevent excessive email.

        For a list of all the issues modified, search jira comments for this
        (hopefully) unique string: 20080415hossman2

        Show
        Hoss Man added a comment - This bug was modified as part of a bulk update using the criteria... Marked ("Resolved" or "Closed") and "Fixed" Had no "Fix Version" versions Was listed in the CHANGES.txt for 1.2 The Fix Version for all 39 issues found was set to 1.2, email notification was suppressed to prevent excessive email. For a list of all the issues modified, search jira comments for this (hopefully) unique string: 20080415hossman2

          People

          • Assignee:
            Unassigned
            Reporter:
            Yonik Seeley
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            Dates

            • Created:
              Updated:
              Resolved:

              Development