#appengine で一回に削除できる件数って500件だったんだ。

DatastoreService#delete(Key akey[]);で500を超えるKEYを引数に渡すと以下のエラーが出た。

org.slim3.controller.Controller runBare: cannot delete more than 500 entities in a single call
java.lang.IllegalArgumentException: cannot delete more than 500 entities in a single call
	at com.google.appengine.api.datastore.DatastoreApiHelper.translateError(DatastoreApiHelper.java:33)
	at com.google.appengine.api.datastore.DatastoreApiHelper.makeSyncCall(DatastoreApiHelper.java:60)
	at com.google.appengine.api.datastore.DatastoreServiceImpl$3.run(DatastoreServiceImpl.java:235)
	at com.google.appengine.api.datastore.TransactionRunner.runInTransaction(TransactionRunner.java:30)
	at com.google.appengine.api.datastore.DatastoreServiceImpl.delete(DatastoreServiceImpl.java:221)
	at com.google.appengine.api.datastore.DatastoreServiceImpl.delete(DatastoreServiceImpl.java:207)
	at org.slim3.datastore.Datastore.deleteInternal(Datastore.java:1816)
	at org.slim3.datastore.Datastore.delete(Datastore.java:1759)