solr 做索引时报 Lock obtain timed out: SingleInstanceLock: write.lock

有个频繁做索引的应用，它同时也对外提供搜索服务。大部分是 solr 1.3 的默认配置。solr 做索引，有时候报：

2009-7-13 9:48:06 org.apache.solr.common.SolrException log
严重: org.apache.lucene.store.LockObtainFailedException: Lock obtain timed out: SingleInstanceLock: write.lock
        at org.apache.lucene.store.Lock.obtain(Lock.java:85)
        at org.apache.lucene.index.IndexWriter.init(IndexWriter.java:1140)
        at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:938)
        at org.apache.solr.update.SolrIndexWriter.<init>(SolrIndexWriter.java:116)
...

是写锁取不到。但重启 solr 又可以正常做，主要是运行时间长了就报这个错了。还是看下配置吧。

看到 solr 1.3 默认的配置是：

<indexDefaults>
    <!-- ... -->
    <!--
      This option specifies which Lucene LockFactory implementation to use.

      single = SingleInstanceLockFactory - suggested for a read-only index
               or when there is no possibility of another process trying
               to modify the index.
      native = NativeFSLockFactory
      simple = SimpleFSLockFactory

      (For backwards compatibility with Solr 1.2, 'simple' is the default
       if not specified.)
    -->
    <lockType>single</lockType>
</indexDefaults>

<indexDefaults> 	<!-- ... -->     <!--       This option specifies which Lucene LockFactory implementation to use.        single = SingleInstanceLockFactory - suggested for a read-only index                or when there is no possibility of another process trying                to modify the index.       native = NativeFSLockFactory       simple = SimpleFSLockFactory        (For backwards compatibility with Solr 1.2, 'simple' is the default        if not specified.)     -->     <lockType>single</lockType> </indexDefaults> 

默认锁是 single ，只读的。solr 1.2 是 simple，把它改回去了，运行了几天，没事。