SOLR:autoSoftCommit最大时间-1是什么意思？

Question

这是我的solrconfig.xml文件的默认设置:

 <autoSoftCommit> 
   <maxTime>${solr.autoSoftCommit.maxTime:-1}</maxTime> 
 </autoSoftCommit>

maxTime为'-1'是否意味着自动软提交已关闭？如果是这样,如果我完全删除了标签,我会得到相同的结果吗？如果我必须手动执行软提交,可以使用'commitWithin'(我用Google搜索但是得到了相互矛盾的答案)吗？

哦,我正在使用Solr 4.5.0

Answer 1

首先,您可以${solr.autoSoftCommit.maxTime:-1}在标记中看到表达式.这允许您使用Solr的变量替换.该特征在参考文献中详细描述.如果该变量未被任何这些方法替换,则将其-1视为该配置的值.

将commitMaxTime设置为-1可以有效地关闭自动提交.如果您查看下面的相关代码,您可以看到,当scheduleCommitWithin方法立即返回时,它会commitMaxTime否决任何值maxDocs.我没有发现记录此行为,所以我查找了代码.

private void _scheduleCommitWithin(long commitMaxTime) {
    if (commitMaxTime <= 0) return;
    synchronized (this) {
      if (pending != null && pending.getDelay(TimeUnit.MILLISECONDS) <= commitMaxTime) {
        // There is already a pending commit that will happen first, so
        // nothing else to do here.
        // log.info("###returning since getDelay()==" + pending.getDelay(TimeUnit.MILLISECONDS) + " less than " + commitMaxTime);

        return;
      }

      if (pending != null) {
        // we need to schedule a commit to happen sooner than the existing one,
        // so lets try to cancel the existing one first.
        boolean canceled = pending.cancel(false);
        if (!canceled) {
          // It looks like we can't cancel... it must have just started running!
          // this is possible due to thread scheduling delays and a low commitMaxTime.
          // Nothing else to do since we obviously can't schedule our commit *before*
          // the one that just started running (or has just completed).
          // log.info("###returning since cancel failed");
          return;
        }
      }

      // log.info("###scheduling for " + commitMaxTime);

      // schedule our new commit
      pending = scheduler.schedule(this, commitMaxTime, TimeUnit.MILLISECONDS);
    }
}

取自https://github.com/apache/lucene-solr/blob/lucene_solr_4_5/solr/core/src/java/org/apache/solr/update/CommitTracker.java

对于问题的第二部分,如果一起删除标记,则与将值设置为-1的结果相同.如下所示,如果xpath表达式返回null,则将获得-1作为默认值.

但是从配置中删除整个表达式也将删除通过Solr的变量替换覆盖该配置的选项.

protected UpdateHandlerInfo loadUpdatehandlerInfo() {
  return new UpdateHandlerInfo(get("updateHandler/@class",null),
    getInt("updateHandler/autoCommit/maxDocs",-1),
    getInt("updateHandler/autoCommit/maxTime",-1),
    getBool("updateHandler/autoCommit/openSearcher",true),
    getInt("updateHandler/commitIntervalLowerBound",-1),
    getInt("updateHandler/autoSoftCommit/maxDocs",-1),
    getInt("updateHandler/autoSoftCommit/maxTime",-1),
    getBool("updateHandler/commitWithin/softCommit",true));
}

取自https://github.com/apache/lucene-solr/blob/lucene_solr_4_5/solr/core/src/java/org/apache/solr/core/SolrConfig.java