CODEWITHSUNDEEP
cassandra
Arik Alon
Arik Alon

Reputation: 3

cassandra error - "if not exists" fails, with replication factor of 2

I have a keyspace with replication factor of 2. I'm running with a single instance cluster.

I'm trying to insert values into a table in that keyspace, with "if not exists" option, and getting an error.

When using without the "if not exists", the row is created.

from cli:

insert into domains (domain, time) values ('test.com', 10) if not exists;

I'm getting: NoHostAvailable:

Running from java client produce the following error:

at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:720) Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: cassandra-service/10.23.251.29:9042 (com.datastax.driver.core.exceptions.UnavailableException: Not enough replicas available for query
at consistency QUORUM (2 required but only 1 alive)))
at com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java:223)
at com.datastax.driver.core.RequestHandler.access$1200(RequestHandler.java:41)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.findNextHostAndQuery(RequestHandler.java:309)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.retry(RequestHandler.java:477)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.processRetryDecision(RequestHandler.java:455)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.onSet(RequestHandler.java:686)
at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1091)
at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1008)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:287)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:284)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
at com.datastax.driver.core.InboundTrafficMeter.channelRead(InboundTrafficMeter.java:29)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1273)
at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1084)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926)
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:979)
at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:401)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:306)
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
at java.lang.Thread.run(Thread.java:748)

Upvotes: 0

Views: 431

Answers (1)

Alex Ott
Alex Ott

Reputation: 87069

You can't have replication factor 2 on the single node cluster - LWT (lightweight transactions, like if not exists requires quorum or local quorum that requires enough amount of nodes! Change replication factor, or add another node.

But the replication factor 2 plus QUORUM isn't very good solution - it means that you can't have any node down, otherwise your transactions will fail.

Upvotes: 2

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