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在 gemfire客户端中的 GF 事务期间查询区域中的字段时，我们看到以下异常。

java.lang.ClassCastException: com.gemstone.gemfire.internal.cache.EntrySnapshot cannot be cast to com.gemstone.gemfire.internal.cache.LocalRegion$NonTXEntry

at com.gemstone.gemfire.internal.cache.EntriesSet$EntriesIterator.moveNext(EntriesSet.java:183) 
at com.gemstone.gemfire.internal.cache.EntriesSet$EntriesIterator.<init>(EntriesSet.java:121) 
at com.gemstone.gemfire.internal.cache.EntriesSet.iterator(EntriesSet.java:85) 
at com.gemstone.gemfire.cache.query.internal.ResultsCollectionWrapper.iterator(ResultsCollectionWrapper.java:181) 
at com.gemstone.gemfire.cache.query.internal.QRegion.iterator(QRegion.java:225) 
at com.gemstone.gemfire.cache.query.internal.CompiledSelect.doNestedIterations(CompiledSelect.java:712) 
at com.gemstone.gemfire.cache.query.internal.CompiledSelect.doIterationEvaluate(CompiledSelect.java:577) 
at com.gemstone.gemfire.cache.query.internal.CompiledSelect.evaluate(CompiledSelect.java:413) 
at com.gemstone.gemfire.cache.query.internal.DefaultQuery.executeUsingContext(DefaultQuery.java:529) 
at com.gemstone.gemfire.cache.query.internal.DefaultQuery.execute(DefaultQuery.java:365)

根据我们的反复试验，它仅在满足以下标准时才会发生

  1. 事务正在运行：即调用gemfireCache.getCacheTransactionManager().begin()然后执行查询

  2. 不为查询/字段创建功能索引QueryService.createIndex(String, String, String)：即在初始化期间未在特定字段上调用

3. where condition在region数据中有一个可以为null的字段：即如果run "SELECT * FROM /REGIONNAME WHERE fieldName = $1"，如果fieldName某个entry为null，则抛出上述异常，否则，正常。

我们正在使用从QueryService.newQuery("SELECT * FROM /REGIONNAME WHERE fieldName = $1"). 如果我没记错的话，查询服务是本地服务，而不是在服务器上运行查询。

我们正在使用 Gemfire 8.2.1

如果您需要更多信息，请在下方评论。

--- 2016 年 5 月 12 日更新 ---

终于有时间整理一个简单的测试用例来说明问题：

我使用 JUnit 启动进程，只是个人习惯。第一个测试用例在端口 40001 上启动一个具有共同定位器的服务器

第二个测试用例启动一个客户端进程并在事务中运行一个没有索引的查询。

public class GemfireQueryInTXTest {

@Test
public void startServer() throws Exception {
    Properties props = new Properties();
    System.setProperty("gemfirePropertyFile", "query_in_tx/gfserver-query-in-tx.properties");
    String file = DistributedSystem.getPropertyFileURL().getFile();
    props.load(new FileReader(file));

    Cache cache = new CacheFactory(props).create();
    RegionFactory<String, ValueEntry> factory = cache
            .<String, ValueEntry>createRegionFactory("REPLICATE")
            .setKeyConstraint(String.class)
            .setValueConstraint(ValueEntry.class);

    Region<String, ValueEntry> valueEntryRegion = factory.create("VALUEENTRY");

    valueEntryRegion.put("first", new ValueEntry("firstEntry", "NotNull"));
    valueEntryRegion.put("second", new ValueEntry("secondEntry", null));

    CacheServer server = cache.addCacheServer();
    server.setPort(40000);

    server.start();

    Thread.sleep(1000000L);
}

@Test
public void testRunningQueryDuringTransactionOnNullableField() throws Exception {
    Properties props = new Properties();
    System.setProperty("gemfirePropertyFile", "query_in_tx/gemfire-query-in-tx.properties");
    String file = DistributedSystem.getPropertyFileURL().getFile();
    props.load(new FileReader(file));

    ClientCache cache = new ClientCacheFactory(props).create();
    ClientRegionFactory<String, ValueEntry> factory = cache
            .<String, ValueEntry>createClientRegionFactory("DEFAULT")
            .setKeyConstraint(String.class)
            .setValueConstraint(ValueEntry.class);

    Region<String, ValueEntry> valueEntryRegion = factory.create("VALUEENTRY");
    valueEntryRegion.registerInterest(".*", InterestResultPolicy.KEYS_VALUES);

    CacheTransactionManager cacheTransactionManager = cache.getCacheTransactionManager();

    QueryService localQueryService = cache.getLocalQueryService();
    Query query = localQueryService.newQuery("SELECT * from /VALUEENTRY WHERE nullable = $1");
    // No Exception will be thrown if create index for the field (uncomment below);
    // localQueryService.createIndex("IndexName", "nullable", "/VALUEENTRY");

    // ... Or run without transaction (comment below tx opening and closing)
    cacheTransactionManager.begin();
    System.out.println("Before Query Executed");
    query.execute(new Object[]{"1"});
    System.out.println("After Query Executed");
    cacheTransactionManager.commit();
}
}

域对象：ValueEntry.java

public class ValueEntry implements DataSerializable {
private String notNull;
private String nullable;

public ValueEntry() {
}

public ValueEntry(String notNull, String nullable) {
    this.notNull = notNull;
    this.nullable = nullable;
}

public String getNotNull() {
    return notNull;
}

public String getNullable() {
    return nullable;
}

@Override
public void toData(DataOutput dataOutput) throws IOException {
    DataSerializer.writeString(notNull, dataOutput);
    DataSerializer.writeString(nullable, dataOutput);
}

@Override
public void fromData(DataInput dataInput) throws IOException, ClassNotFoundException {
    this.notNull = DataSerializer.readString(dataInput);
    this.nullable = DataSerializer.readString(dataInput);
}
}

服务器属性和 xml：

cache-xml-file=query_in_tx\\cache-server.xml
start-locator=40001
locators=localhost[40001]
log-file=logs\\server.log
log-level=config
mcast-port=0
name=server

<cache>
<serialization-registration>
    <instantiator id="999">
        <class-name>com.testing.gemfire.domain.ValueEntry</class-name>
    </instantiator>
</serialization-registration>
</cache>

客户端属性和 xml：

cache-xml-file=query_in_tx\\cache-query-in-tx.xml
log-disk-space-limit=100
log-file-size-limit=20
log-file=logs\\cache.log
log-level=config
mcast-port=0
name=gemfire-playground

<client-cache>
    <pool name="Zero" subscription-enabled="true" read-timeout="3000"
          retry-attempts="5" socket-buffer-size="65536">
        <locator host="localhost" port="40001" />
    </pool>

    <region-attributes id="DEFAULT" refid="CACHING_PROXY" pool-name="Zero"/>
</client-cache>
4

1 回答 1

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与 Pivotal 团队沟通后，发现这是 Gemfire 客户端的错误。如问题描述中所述，创建索引将阻止抛出此异常。

如果在未来的版本中修复，我会再次更新。

于 2016-12-18T08:48:22.720 回答