Cassandra群集中出现意外的不可用异常 我有一个3节点的C*集群 C*客户端已将读取一致性级别设置为仲裁 当集群中的一个节点停机时,我会收到一个不可用的异常以响应读取查询
为什么?由3个节点组成的群集的仲裁为2,因此它应该处理一个节点的中断 还有一些细节: 卡桑德拉版本:Cassandra群集中出现意外的不可用异常 我有一个3节点的C*集群 C*客户端已将读取一致性级别设置为仲裁 当集群中的一个节点停机时,我会收到一个不可用的异常以响应读取查询,cassandra,astyanax,Cassandra,Astyanax,为什么?由3个节点组成的群集的仲裁为2,因此它应该处理一个节点的中断 还有一些细节: 卡桑德拉版本: ReleaseVersion: 1.1.6 键空间和列族的配置: Keyspace: QuestionAnswerService: Replication Strategy: org.apache.cassandra.locator.NetworkTopologyStrategy Durable Writes: true Options: [datacenter1:2] C
ReleaseVersion: 1.1.6
键空间和列族的配置:
Keyspace: QuestionAnswerService:
Replication Strategy: org.apache.cassandra.locator.NetworkTopologyStrategy
Durable Writes: true
Options: [datacenter1:2]
Column Families:
//...
ColumnFamily: answersByQuestion
Key Validation Class: org.apache.cassandra.db.marshal.BytesType
Default column value validator: org.apache.cassandra.db.marshal.BytesType
Columns sorted by: org.apache.cassandra.db.marshal.BytesType
GC grace seconds: 864000
Compaction min/max thresholds: 4/32
Read repair chance: 1.0
DC Local Read repair chance: 0.0
Populate IO Cache on flush: false
Replicate on write: true
Caching: KEYS_ONLY
Bloom Filter FP chance: default
Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy
Compression Options:
sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor
//...
当一个节点关闭时,在读取查询期间引发异常:
2013-05-21 17:43:37 ERROR CountingConnectionPoolMonitor:81 - com.netflix.astyanax.connectionpool.exceptions.TokenRangeOfflineException: TokenRangeOfflineException: [host=cassandra.xxx.yyy(10.33.0.53):9160, latency=56(56), attempts=1]UnavailableException()
com.netflix.astyanax.connectionpool.exceptions.TokenRangeOfflineException: TokenRangeOfflineException: [host=cassandra.xxx.yyy(10.33.0.53):9160, latency=56(56), attempts=1]UnavailableException()
at com.netflix.astyanax.thrift.ThriftConverter.ToConnectionPoolException(ThriftConverter.java:165)
at com.netflix.astyanax.thrift.AbstractOperationImpl.execute(AbstractOperationImpl.java:60)
at com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl$1$2.execute(ThriftColumnFamilyQueryImpl.java:198)
at com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl$1$2.execute(ThriftColumnFamilyQueryImpl.java:190)
at com.netflix.astyanax.thrift.ThriftSyncConnectionFactoryImpl$1.execute(ThriftSyncConnectionFactoryImpl.java:136)
at com.netflix.astyanax.connectionpool.impl.AbstractExecuteWithFailoverImpl.tryOperation(AbstractExecuteWithFailoverImpl.java:69)
at com.netflix.astyanax.connectionpool.impl.AbstractHostPartitionConnectionPool.executeWithFailover(AbstractHostPartitionConnectionPool.java:248)
at com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl$1.execute(ThriftColumnFamilyQueryImpl.java:188)
at org.example.Casstest$delayedInit$body.apply(Casstest.scala:66)
at scala.Function0$class.apply$mcV$sp(Function0.scala:34)
at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
at scala.App$$anonfun$main$1.apply(App.scala:60)
at scala.App$$anonfun$main$1.apply(App.scala:60)
at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)
at scala.collection.immutable.List.foreach(List.scala:45)
at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:30)
at scala.App$class.main(App.scala:60)
at org.example.Casstest$.main(Casstest.scala:14)
at org.example.Casstest.main(Casstest.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: UnavailableException()
at org.apache.cassandra.thrift.Cassandra$get_slice_result.read(Cassandra.java:7288)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
at org.apache.cassandra.thrift.Cassandra$Client.recv_get_slice(Cassandra.java:552)
at org.apache.cassandra.thrift.Cassandra$Client.get_slice(Cassandra.java:536)
at com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl$1$2.internalExecute(ThriftColumnFamilyQueryImpl.java:203)
at com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl$1$2.internalExecute(ThriftColumnFamilyQueryImpl.java:190)
at com.netflix.astyanax.thrift.AbstractOperationImpl.execute(AbstractOperationImpl.java:55)
... 22 more
Scala中再现上述错误的代码:
package org.example
import com.netflix.astyanax.connectionpool.impl.{CountingConnectionPoolMonitor, ConnectionPoolConfigurationImpl}
import com.netflix.astyanax.{Keyspace, AstyanaxContext}
import com.netflix.astyanax.impl.AstyanaxConfigurationImpl
import com.netflix.astyanax.connectionpool.NodeDiscoveryType
import com.netflix.astyanax.retry.ConstantBackoff
import com.netflix.astyanax.model.{ColumnFamily, ConsistencyLevel}
import com.netflix.astyanax.thrift.ThriftFamilyFactory
import com.netflix.astyanax.serializers.StringSerializer
import org.slf4j.LoggerFactory
import scala.collection.JavaConversions._
object Casstest extends App {
println("Hello, cass-test")
val logger = LoggerFactory.getLogger(Casstest.getClass)
val clusterName = "Cassandra"
val hostname = "cassandra.xxx.yyy"
val port = 9160
val thriftSocketTimeout = 4000
val keyspaceName = "QuestionAnswerService"
val timeout = 5000
val connectionPool = new ConnectionPoolConfigurationImpl("ConnectionPool")
.setPort(port)
// .setMaxConnsPerHost(1)
.setSeeds(hostname + ":" + port)
.setSocketTimeout(timeout)
.setConnectTimeout(timeout)
.setTimeoutWindow(timeout)
val cassandraContext: AstyanaxContext[Keyspace] =
new AstyanaxContext.Builder()
.forCluster(clusterName)
.withAstyanaxConfiguration(new AstyanaxConfigurationImpl()
.setDiscoveryType(NodeDiscoveryType.TOKEN_AWARE)
.setRetryPolicy(new ConstantBackoff(timeout, 10000))
.setDefaultReadConsistencyLevel(ConsistencyLevel.CL_QUORUM))
.withConnectionPoolConfiguration(connectionPool)
.withConnectionPoolMonitor(new CountingConnectionPoolMonitor())
.forKeyspace(keyspaceName)
.buildKeyspace(ThriftFamilyFactory.getInstance())
cassandraContext.start()
val keyspace: Keyspace = cassandraContext.getEntity()
val answersByQuestionCf = new ColumnFamily[String, String](
"answersByQuestion", // Column Family Name
StringSerializer.get(), // Key Serializer
StringSerializer.get(), // Column Serializer
StringSerializer.get()) // Value Serializer
while(true) {
logger.info("query start")
val result = keyspace
.prepareQuery(answersByQuestionCf)
.getKey("birthyear")
.execute()
logger.info("query finished: " + result.toString)
result.getResult.getColumnNames.take(10) foreach {
logger.info
}
}
}
一致性级别所需的节点数是复制因子的函数,而不是集群中的节点数。因此,对于RF=2,仲裁为2,因此所有节点都必须能够读取所有数据 群集中有3个节点,RF=2,在CL.QUORUM上读取数据,一个节点关闭时,您只能访问1/3的数据。读取其他键将导致不可用的异常
群集中有3个节点,RF=3,在CL.QUORUM上读取数据,在一个节点关闭的情况下,您仍然可以访问所有数据。您的所有节点都在datacenter1中吗?您可以通过cassandra cli进行读写吗?可以。更重要的是,我刚刚发现将复制因子增加到3解决了这个问题——我可以在一个节点关闭的情况下成功地进行查询。然而,根据文件,这不应该造成差异。对于RF=2和RF=3,仲裁=2链接:[关于读取一致性]