私は現在 Cassandra を試しています。
クライアント側 (Hector を使用) では、次のようないくつかのキーを検索します。
ColumnFamilyResult<String, String> result = template.queryColumns(Arrays.asList("key1","key2","key3"));
ほとんどの場合、うまくいくようです。しかし、クライアントでタイムアウト例外が発生する場合もあります。
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$1.execute(ThriftColumnFamilyTemplate.java:95)
サーバーでは、この例外が表示されます。
ERROR 11:33:55,312 Exception in thread Thread[ReadStage:91,5,main]
java.lang.AssertionError: DecoratedKey(4948402862350542345439897754126541659, 6932) != DecoratedKey(132475956107784875457507977471906551877, 726f6f74) in C:\tem
p\cassandra\lib\cassandra\data\CassandraPolepos\ComplexObjects\CassandraPolepos-ComplexObjects-hd-2-Data.db
at org.apache.cassandra.db.columniterator.SSTableSliceIterator.<init>(SSTableSliceIterator.java:58)
at org.apache.cassandra.db.filter.SliceQueryFilter.getSSTableColumnIterator(SliceQueryFilter.java:66)
at org.apache.cassandra.db.filter.QueryFilter.getSSTableColumnIterator(QueryFilter.java:78)
at org.apache.cassandra.db.CollationController.collectAllData(CollationController.java:256)
at org.apache.cassandra.db.CollationController.getTopLevelColumns(CollationController.java:63)
at org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1331)
at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1193)
at org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1128)
at org.apache.cassandra.db.Table.getRow(Table.java:378)
at org.apache.cassandra.db.SliceFromReadCommand.getRow(SliceFromReadCommand.java:69)
at org.apache.cassandra.service.StorageProxy$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)
DecoratedKey(...) 部分のキー値がページを占有することがあります。
誰でも私が間違っていることのヒント。または、この問題を調査する方法。
ありがとう。