Apache Solr 5.4.1 发布，更新如下：
Bug Fixes (8)
SOLR-8460: /analysis/field could throw exceptions for custom attributes.
(David Smiley, Uwe Schindler)
SOLR-8373: KerberosPlugin: Using multiple nodes on same machine leads clients to fetch TGT for every request
(Ishan Chattopadhyaya via noble)
SOLR-8059: &debug=results for distributed search when distrib.singlePass (sometimes activated automatically) could result in an NPE.
(David Smiley, Markus Jelsma)
SOLR-8422: When authentication enabled, requests fail if sent to a node that doesn't host the collection
SOLR-7462: AIOOBE in RecordingJSONParser
(Scott Dawson, noble)
SOLR-8496: SolrIndexSearcher.getDocSet(List<Query>) incorrectly included deleted documents when all of the queries were uncached (or there was no filter cache). This caused multi-select faceting (including the JSON Facet API) to include deleted doc counts when the remaining non-excluded filters were all uncached. This bug was first introduced in 5.3.0
(Andreas Müller, Vasiliy Bout, Erick Erickson, Shawn Heisey, Hossman, yonik)
SOLR-8561: Doing a rolling upgrade to 5.4.0 fails because the new nodes cannot find the shard leader properties where they expect. This bug was first introduced in 5.4.0 and a fallback was added so that the leader properties are searched in both the old location and the new one.
New Features (1)
SOLR-8470: Make TTL of PKIAuthenticationPlugin's tokens configurable through a system property (pkiauth.ttl)
Apache Solr (读音: SOLer) 是一个开源的搜索服务器。Solr 使用 Java 语言开发，主要基于 HTTP 和 Apache Lucene
实现。Apache Solr 中存储的资源是以 Document 为对象进行存储的。每个文档由一系列的 Field 构成，每个 Field
表示资源的一个属性。Solr 中的每个 Document 需要有能唯一标识其自身的属性，默认情况下这个属性的名字是 id，在 Schema