java - 内存不足错误: Java heap space GoogleAppEngine

Question

在 AppEngine 上运行一个应用程序。已运行2年，运行良好。今天检查了一下，发现它失败了。好久没碰代码了。

我得到的错误是这样的:

java.lang.OutOfMemoryError: Java heap space
at com.google.storage.onestore.v3.OnestoreEntity$Property.<init>(OnestoreEntity.java:2849)
at com.google.storage.onestore.v3.OnestoreEntity$EntityProto.addProperty(OnestoreEntity.java:5755)
at com.google.storage.onestore.v3.OnestoreEntity$EntityProto.merge(OnestoreEntity.java:6232)
at com.google.apphosting.api.DatastorePb$QueryResult.merge(DatastorePb.java:13045)
at com.google.appengine.repackaged.com.google.io.protocol.ProtocolMessage.mergeFrom(ProtocolMessage.java:405)
at com.google.appengine.repackaged.com.google.io.protocol.ProtocolMessage.mergeFrom(ProtocolMessage.java:422)
at com.google.appengine.repackaged.com.google.io.protocol.ProtocolMessage.parseFrom(ProtocolMessage.java:534)
at com.google.appengine.api.datastore.DatastoreApiHelper$1.wrap(DatastoreApiHelper.java:90)
at com.google.appengine.api.datastore.DatastoreApiHelper$1.wrap(DatastoreApiHelper.java:83)
at com.google.appengine.api.utils.FutureWrapper.wrapAndCache(FutureWrapper.java:51)
at com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:67)
at com.google.appengine.api.datastore.FutureHelper.getInternal(FutureHelper.java:71)
at com.google.appengine.api.datastore.FutureHelper.quietGet(FutureHelper.java:32)
at com.google.appengine.api.datastore.QueryResultsSourceImpl.loadMoreEntities(QueryResultsSourceImpl.java:69)
at com.google.appengine.api.datastore.QueryResultsSourceImpl.loadMoreEntities(QueryResultsSourceImpl.java:56)
at com.google.appengine.api.datastore.QueryResultIteratorImpl.ensureLoaded(QueryResultIteratorImpl.java:156)
at com.google.appengine.api.datastore.QueryResultIteratorImpl.hasNext(QueryResultIteratorImpl.java:65)
at org.datanucleus.store.appengine.query.RuntimeExceptionWrappingIterator$1.get(RuntimeExceptionWrappingIterator.java:50)
at org.datanucleus.store.appengine.query.RuntimeExceptionWrappingIterator$1.get(RuntimeExceptionWrappingIterator.java:47)
at org.datanucleus.store.appengine.query.QueryExceptionWrappers$1.get(QueryExceptionWrappers.java:51)
at org.datanucleus.store.appengine.query.QueryExceptionWrappers$2.get(QueryExceptionWrappers.java:86)
at org.datanucleus.store.appengine.query.RuntimeExceptionWrappingIterator.hasNext(RuntimeExceptionWrappingIterator.java:105)
at org.datanucleus.store.appengine.query.LazyResult.resolveAll(LazyResult.java:115)
at org.datanucleus.store.appengine.query.LazyResult.size(LazyResult.java:110)
at org.datanucleus.store.appengine.query.StreamingQueryResult.size(StreamingQueryResult.java:130)
at guestbook.ProxyServlet.processRequest(ProxyServlet.java:132)
at guestbook.ProxyServlet.doGet(ProxyServlet.java:288)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:97)

我的代理 servlet 中第 132 行的代码访问我从数据库检索的实体列表。就是这一行“System.out.println("from db "+allEventsLst.size());"

当我运行本地服务器时，我的应用程序可以运行。有什么想法吗？？？

    String fromDateStr = shortDf.format(fromDate);



    Query query = pm.newQuery(Event.class, "date >= fromDate");
      query.declareImports("import java.lang.String");
      query.declareParameters("String fromDate");    

    List<Event> allEventsLst = (List<Event>)query.execute(fromDateStr);

    System.out.println("from db "+allEventsLst.size());

    Map<String, Event> eventMap = new HashMap<String, Event>();

    for (Event e : allEventsLst) {

谢谢

Answer 1

不太确定，但可能是 List 是延迟加载的，当您调用 size 方法时，它必须加载所有元素。由于您的应用程序已经运行了一段时间，它可能有足够的元素导致内存不足问题。