I am inserting data in cassandra from a csv file using java driver.But after some inserts it throws NoHostAvailableException:java 65 :All host(s) tried for query failed (no host was tried).
I am having cassandra on client machine (singlenode).Cassandra services are still running on client machine.
Thanks in advance.I am a newbie.
Here's some best practices for bulk ingestions using the java driver:
http://lostechies.com/ryansvihla/2014/08/28/cassandra-batch-loading-without-the-batch-keyword/
I got this problem solved by using executeasync method present in the java driver.
Related
we have tested a lot in many scenes in small data.
if use cassandra installed without cluster，then everything is ok，but if we use cassandra in cluster，then it will cost more then about 15 seconds at the same function.
Our java code is just as the sample code.Purely, call the dataset.collectAsList() or dataset.head(10)。
But if we use scala ，the same logic in spark-shell don't have the problem.
We have test a lot jdks and systems.Mac OS is fine, but window OS and linux OS like centos both have this problem.
collectAsList or head function，will try to getHostName，this is a expensive operation.So we can't use Ip to connect cassandra cluster, we have to use HOSTNAME to connect it.And it works!!!! the code of spark cassandra connector have to fix this problems.
I'm looking to log all logs in Cassandra 3.4.4 (for instance, to log if query was ok, bad, but also connection timed out or bad credentials). Thanks
Unfortunately Cassandra 3 doesn’t have a feature for that. However, there is an open source 3rd party plugin that does this.
Check out Ericsson’s Cassandra Query Logger:
https://github.com/Ericsson/ecaudit/
Basically, you download the JAR, add it to lib/, reference it in the Cassandra-env.sh, and that should do it.
I am trying to get to know Cassandra cfstats information from all the machines using JMX. This can be done using OpsCenter, but I do not want to use it. I started building my own utility. For now, my java program connects to JMX and fetching cfstats information such as estimateKeys, No of SSTables ..etc.
My requirement is, This is a java jar file, will run from one Cassandra node and should be able to connect to all the machines and fetch cfstats using their respective JMX per node.
I am planning to use java driver for this, as java driver will be able to connects all the machines in the cluster using system.peers coumnFamily. Once java driver connect to the machines, I will form the service:jmx:rmi using respective hostname and JMX port(7199). Then I will be able to connect to NodeProbe using this information.
My question is, after connecting to the another node using java driver, will I be able to retain state there and after forming service:jmx:rmi url, will this url really connects to the current node JMX and pull cfstats information from the current node. Because JMX host name it will take from the Cassandra-env.sh file. Can some one please help me in this.
Does this idea works or is there another best way to achieve this?
It's possible to use JMX remotely, but that's not the easiest thing to do.
But if you are writing your tool - maybe it's worth to check out a different connection. E.g. you can easily convert JMX calls to HTTP using Jolokia
I have an application that connects to Cassandra using the Java Driver, fetches some configuration and based on the results generates and executes some PIG scripts.
Now, I am able to successfully connect to Cassandra, when jars required for PIG are not in the classpath. Similarly, I am able to launch PigServer class and execute scripts / statements using the entire DSE stack when I am not connecting to Cassandra using the java driver to retrieve the configuration.
When I use both of them I get following exception:
org.jboss.netty.channel.ChannelPipelineException: Failed to initialize a pipeline.
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:181)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:570)
... 35 more
Caused by: org.jboss.netty.channel.ChannelPipelineException: Failed to initialize a pipeline.
at org.jboss.netty.bootstrap.ClientBootstrap.connect(ClientBootstrap.java:208)
at org.jboss.netty.bootstrap.ClientBootstrap.connect(ClientBootstrap.java:182)
at com.datastax.driver.core.Connection.<init>(Connection.java:100)
at com.datastax.driver.core.Connection.<init>(Connection.java:51)
at com.datastax.driver.core.Connection$Factory.open(Connection.java:376)
at com.datastax.driver.core.ControlConnection.tryConnect(ControlConnection.java:207)
at com.datastax.driver.core.ControlConnection.reconnectInternal(ControlConnection.java:170)
at com.datastax.driver.core.ControlConnection.connect(ControlConnection.java:87)
at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:576)
at com.datastax.driver.core.Cluster$Manager.access$100(Cluster.java:520)
at com.datastax.driver.core.Cluster.<init>(Cluster.java:67)
at com.datastax.driver.core.Cluster.buildFrom(Cluster.java:94)
at com.datastax.driver.core.Cluster$Builder.build(Cluster.java:501)
I see others have seen similar exception, but when trying to execute Cassandra statements, from MapReduce tasks, which is not my case:
https://groups.google.com/a/lists.datastax.com/forum/#!topic/java-driver-user/FhW_8e4FyAI
http://www.datastax.com/dev/blog/the-native-cql-java-driver-goes-ga#comment-297187
Thanks!
DSE stacks connect to Cassandra through thrift API which is different from Cassandra Java Driver.
You can't use Cassandra Java driver for Pig/Hadoop before CASSANDRA-6311 is resolved.
There may be the bad security certificate/security certificate expiration issue if you are using certificate.
If I create a new project like this .
cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
this code works.
But if I take all the jars from this project and migrate the jars to my own project .the code above doesn't work and it says:
13/07/01 16:27:16 ERROR core.Connection: [/127.0.0.1-1] No handler set for stream 1 (this is a bug, either of this driver or of Cassandra, you should report it)
com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: [/127.0.0.1])
What version of Cassandra are you running? Have you enabled the native protocol in your cassandra.yaml?
In Cassandra 1.2.0-1.2.4 the native protocol was disabled by default, but in 1.2.5+ it's on by default.
See https://github.com/apache/cassandra/blob/cassandra-1.2.5/conf/cassandra.yaml#L335
That's the most common reason I've seen for not being able to connect with the driver.