我目前正在尝试 Cassandra。

在客户端(使用 Hector)我查找一些像这样的键:

ColumnFamilyResult result = template.queryColumns(Arrays.asList("key1","key2","key3"));

大多数时候它似乎都有效。但其他时候我在客户端遇到超时异常:

Caused by: me.prettyprint.hector.api.exceptions.HTimedOutException: TimedOutException()
    at me.prettyprint.cassandra.service.ExceptionsTranslatorImpl.translate(ExceptionsTranslatorImpl.java:35)
    at me.prettyprint.cassandra.service.template.ThriftColumnFamilyTemplate$1.execute(ThriftColumnFamilyTemplate.java:100)
    at me.prettyprint.cassandra.service.template.ThriftColumnFamilyTemplate$1.execute(ThriftColumnFamilyTemplate.java:88)
    at me.prettyprint.cassandra.service.Operation.executeAndSetResult(Operation.java:103)
    at me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:258)
    at me.prettyprint.cassandra.model.ExecutingKeyspace.doExecuteOperation(ExecutingKeyspace.java:97)
    at me.prettyprint.cassandra.service.template.ThriftColumnFamilyTemplate.sliceInternal(ThriftColumnFamilyTemplate.java:88)
    at me.prettyprint.cassandra.service.template.ThriftColumnFamilyTemplate.doExecuteSlice(ThriftColumnFamilyTemplate.java:46)
    at me.prettyprint.cassandra.service.template.ColumnFamilyTemplate.queryColumns(ColumnFamilyTemplate.java:113)
    at info.gamlor.experiments.Cassandra.readObjectByKey(ComplexCassandra.java:255)

Caused by: TimedOutException()
    at org.apache.cassandra.thrift.Cassandra$get_slice_result.read(Cassandra.java:7772)
    at org.apache.cassandra.thrift.Cassandra$Client.recv_get_slice(Cassandra.java:570)
    at org.apache.cassandra.thrift.Cassandra$Client.get_slice(Cassandra.java:542)
    at me.prettyprint.cassandra.service.template.ThriftColumnFamilyTemplate$1.execute(ThriftColumnFamilyTemplate.java:95)

在服务器上出现此异常:

ERROR 11:33:55,312 Exception in thread Thread[ReadStage:91,5,main]
java.lang.AssertionError: DecoratedKey(4948402862350542345439897754126541659, 6932) != DecoratedKey(132475956107784875457507977471906551877, 726f6f74) in C:\tem
p\cassandra\lib\cassandra\data\CassandraPolepos\ComplexObjects\CassandraPolepos-ComplexObjects-hd-2-Data.db
        at org.apache.cassandra.db.columniterator.SSTableSliceIterator.(SSTableSliceIterator.java:58)
        at org.apache.cassandra.db.filter.SliceQueryFilter.getSSTableColumnIterator(SliceQueryFilter.java:66)
        at org.apache.cassandra.db.filter.QueryFilter.getSSTableColumnIterator(QueryFilter.java:78)
        at org.apache.cassandra.db.CollationController.collectAllData(CollationController.java:256)
        at org.apache.cassandra.db.CollationController.getTopLevelColumns(CollationController.java:63)
        at org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1331)
        at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1193)
        at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1128)
        at org.apache.cassandra.db.Table.getRow(Table.java:378)
        at org.apache.cassandra.db.SliceFromReadCommand.getRow(SliceFromReadCommand.java:69)
        at org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayThrow(StorageProxy.java:816)
        at org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:1250)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
        at java.lang.Thread.run(Thread.java:722)

有时 DecoratedKey(...) 部分中的键值会占用页面。

任何人都暗示我做错了什么。或者说如何调查这个问题。

Cảm ơn.

1 Câu trả lời

Đây là https://issues.apache.org/jira/browse/CASSANDRA-4687hoặchttps://issues.apache.org/jira/browse/CASSANDRA-5202您可以在所有显示错误的服务器上运行命令“nodetool invalidatekeycache”。如果它继续出现，您可能需要禁用 key 缓存。如果是 5202，则只有在删除并使用相同名称重新创建列族后才会发生。

关于Cassandra 服务器抛出 java.lang.AssertionError : DecoratedKey(. ..) != DecoratedKey，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/11623356/