SOLR: -1 的 autoSoftCommit maxtime 是什么意思？

Question

这是我的 solrconfig.xml 文件中的默认设置:

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

“-1”的 maxTime 是否意味着自动软提交已关闭？如果是这样，如果我完全删除标签，我会得到相同的结果吗？如果我必须手动进行软提交，可以使用“commitWithin”来完成吗(我用谷歌搜索了这个但得到了相互矛盾的答案)？

哦，我正在使用 Solr 4.5.0

Answer 1

首先，您可以看到表达式 ${solr.autoSoftCommit.maxTime:-1}标签内。这允许您使用 Solr 的 变量替换 .详细描述了该功能 here in the reference .如果该变量没有被任何这些方法替换 -1被视为该配置的值。

将 commitMaxTime 设为 -1 有效地关闭自动提交。如果你看看下面的相关代码，你可以看到commitMaxTime否决 maxDocs 的任何值，因为 scheduleCommitWithin 方法会立即返回。我没有发现这种行为记录，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

对于您问题的第二部分，如果您 移除标签 总之，这将与将值设置为 -1 具有相同的结果。正如您在下面看到的，如果 xpath 表达式返回 null，您将获得 -1 作为默认值。

但是从配置中删除整个表达式也会删除通过 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