我在尝试使用客户端Astyanax连接到EC2实例上的Cassandra时收到以下错误“astyanax.connectionpool.exceptions.PoolTimeoutException：”。需要帮助
Following is my code snippet.
import org.mortbay.jetty.servlet.Context;
import com.netflix.astyanax.AstyanaxContext;
import com.netflix.astyanax.Keyspace;
import com.netflix.astyanax.MutationBatch;
import com.netflix.astyanax.connectionpool.NodeDiscoveryType;
import com.netflix.astyanax.connectionpool.OperationResult;
import com.netflix.astyanax.connectionpool.exceptions.ConnectionException;
import com.netflix.astyanax.connectionpool.impl.ConnectionPoolConfigurationImpl;
import com.netflix.astyanax.connectionpool.impl.ConnectionPoolType;
import com.netflix.astyanax.connectionpool.impl.CountingConnectionPoolMonitor;
import com.netflix.astyanax.impl.AstyanaxConfigurationImpl;
import com.netflix.astyanax.model.Column;
import com.netflix.astyanax.model.ColumnFamily;
import com.netflix.astyanax.model.ColumnList;
import com.netflix.astyanax.model.CqlResult;
import com.netflix.astyanax.serializers.StringSerializer;
import com.netflix.astyanax.thrift.ThriftFamilyFactory;
public class MetadataRS {
public static void main(String args[]){
AstyanaxContext<Keyspace> context = new AstyanaxContext.Builder()
.forCluster("ClusterName")
.forKeyspace("KeyspaceName")
.withAstyanaxConfiguration(new AstyanaxConfigurationImpl()
.setDiscoveryType(NodeDiscoveryType.RING_DESCRIBE)
.setConnectionPoolType(ConnectionPoolType.ROUND_ROBIN)
)
.withConnectionPoolConfiguration(new ConnectionPoolConfigurationImpl("MyConnectionPool")
.setPort(9042)
.setMaxConnsPerHost(40)
.setSeeds("<EC2-IP>:9042")
.setConnectTimeout(5000)
)
.withConnectionPoolMonitor(new CountingConnectionPoolMonitor())
.buildKeyspace(ThriftFamilyFactory.getInstance());
context.start();
Keyspace keyspace = context.getEntity();
System.out.println(keyspace);
ColumnFamily<String, String> CF_USER_INFO =
new ColumnFamily<String, String>(
"Standard1", // Column Family Name
StringSerializer.get(), // Key Serializer
StringSerializer.get()); // Column
OperationResult<ColumnList<String>> result = null;
try {
result = keyspace.prepareQuery(CF_USER_INFO)
.getKey("user_id_hash")
.execute();
} catch (ConnectionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ColumnList<String> columns = result.getResult();
// Lookup columns in response by name
String uid = columns.getColumnByName("user_id_hash").getStringValue();
System.out.println(uid);
// Or, iterate through the columns
for (Column<String> c : result.getResult()) {
System.out.println(c.getName());
}
}
}
错误 com.netflix.astyanax.thrift.ThriftKeyspaceImpl@1961f4 com.netflix.astyanax.connectionpool.exceptions.PoolTimeoutException：PoolTimeoutException：[host =（）：9042，latency = 5001（5001），attempts = 1]超时等待连接 在com.netflix.astyanax.connectionpool.impl.SimpleHostConnectionPool.waitForConnection（SimpleHostConnectionPool.java:201） 在com.netflix.astyanax.connectionpool.impl.SimpleHostConnectionPool.borrowConnection（SimpleHostConnectionPool.java:158） 在com.netflix.astyanax.connectionpool.impl.RoundRobinExecuteWithFailover.borrowConnection（RoundRobinExecuteWithFailover.java:60） at com.netflix.astyanax.connectionpool.impl.AbstractExecuteWithFailoverImpl.tryOperation（AbstractExecuteWithFailoverImpl.java:50） at com.netflix.astyanax.connectionpool.impl.AbstractHostPartitionConnectionPool.executeWithFailover（AbstractHostPartitionConnectionPool.java:229） 在com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl $ 1.execute（ThriftColumnFamilyQueryImpl.java:180） 在com.rjil.jiodrive.rs.MetadataRS.main（MetadataRS.java:57） 线程“main”java.lang.NullPointerException中的异常 在com.rjil.jiodrive.rs.MetadataRS.main（MetadataRS.java:62）
答案 0 :(得分：0)
您的问题不在您的代码中。您指定为种子的节点存在连接问题。因此，该节点未运行，或者您无法从运行客户端的计算机上访问该节点。
答案 1 :(得分：0)
由于您在EC2实例上运行cassandra，请检查cassandra的端口号是否存在。 （您已选择9042）位于ec2安全组的允许列表中，并且您可以访问它。如果没有添加端口号。在ec2安全组的入站列表中，将ip范围设置为0.0.0.0。 Alos检查ec2上的防火墙是否已关闭。默认情况下它是假的，但无论如何都要检查它。
如果您已经这样做了，那么您的客户可能会在防火墙后面阻止出站流量到您选择的端口（9042）。
最后，如果你没有使用任何弹性ip，最好在你的setSeeds部分和cassandra.yaml的rpc_address中使用ec2实例dns名称
答案 2 :(得分：0)
我最终将libthrift升级到0.9并将我的代码更改为以下内容并且现在工作正常。
public Keyspace getDBConnection() {
if (poolConfig == null) {
poolConfig = new ConnectionPoolConfigurationImpl(
"CassandraPool").setPort(port).setMaxConnsPerHost(1)
.setSeeds((new StringBuilder(seedHost).append(":").append(port).toString()))
.setLatencyAwareUpdateInterval(latencyAwareUpdateInterval) // Will resort hosts per
// token partition every
// 10 seconds
.setLatencyAwareResetInterval(latencyAwareResetInterval) // Will clear the latency
// every 10 seconds. In
// practice I set this
// to 0 which is the
// default. It's better
// to be 0.
.setLatencyAwareBadnessThreshold(latencyAwareBadnessThreshold) // Will sort hosts if a host
// is more than 100% slower
// than the best and always
// assign connections to the
// fastest host, otherwise
// will use round robin
.setLatencyAwareWindowSize(latencyAwareWindowSize) // Uses last 100 latency
// samples. These samples are in
// a FIFO q and will just cycle
// themselves.
.setTimeoutWindow(60000)
;
}
AstyanaxContext<Keyspace> context = new AstyanaxContext.Builder()
.forCluster(clusterName)
.forKeyspace(keyspaceName)
.withAstyanaxConfiguration(
new AstyanaxConfigurationImpl().setDiscoveryType(
NodeDiscoveryType.NONE)
.setConnectionPoolType(
ConnectionPoolType.ROUND_ROBIN)
.setCqlVersion("3.0.0")
.setTargetCassandraVersion("2.0"))
.withConnectionPoolConfiguration(poolConfig)
.withConnectionPoolMonitor(new CountingConnectionPoolMonitor())
.buildKeyspace(ThriftFamilyFactory.getInstance());
context.start();
return context.getClient();
}