I installed Cassandra on Windows 10. When i trying to run cqlsh from /bin/,
I get the following error:
Connection error: ('Unable to connect to any servers', {'127.0.0.1': \
error(10061, "Tried connecting to [('127.0.0.1', 9042)].
Last error: No connection could be made because the target machine \
actively refused it")})
I installed Cassandra from apache.org official site . also I get reference from
https://phoenixnap.com/kb/install-cassandra-on-windows - Everything is looks good from the reference.
can anyone help me to solve this ? thanks in Advance.
The error states that cqlsh can't connect to the local Cassandra instance. The default configuration in conf/cassandra.yaml is for Cassandra to listen for CQL clients on localhost (127.0.0.1) and CQL port 9042:
native_transport_port: 9042
rpc_address: localhost
Since you're getting a "connection refused" error, the most likely issue is that Cassandra is not running on your Windows machine. Check the Cassandra logs (usually in logs/system.log) for errors which would provide clues as to why Cassandra couldn't start.
As a side note, there is very limited Windows support in Cassandra 3.x and there are several known issues that will not be fixed due to limitations in the operating system.
Furthermore, Windows support has been completely dropped in Cassandra 4.0 due to lack of maintainers and testing (CASSANDRA-16171).
As a workaround, we recommend the following:
Deploy Cassandra in Docker
Deploy Cassandra in a VM using software like VirtualBox
Deploy K8ssandra.io
If you just want to build apps with Cassandra as a backend, Astra DB has a free tier that lets you launch a Cassandra cluster in a few clicks with no credit card required. Cheers!
Do you keep this terminal open and Cassandra runs when you are trying to connect? Notice you have to launch cqlsh from a different terminal window.
Please check the steps again, mostly probably Cassandra simply doesn't run. Keep attention on the p.4 specially.
Related
I am about to use simple cassnadra cluster (3 nodes, x.x.x.104-106). I'm using CentOS7, so i used datastax repository, Cassandra 3.0.
I read on forum, it is better to install the cassandra-stress outside the cluster, otherwise it consumes CPU of the node.
Could you please help me, how to install it?
I tried to copied cassandra-stress.sh separately, but it is dependent on some cassandra files (probably created during installation).
So I decided to install whole Cassandra on separate server, in the same network space. Now, I'm struggling with the correct setup, how to run cassandra-stress tool against the cassandra cluster.
In cassandra.yaml I setup Cassandra name, listen_adress to public_ip, rpc_address to loopback address, I set seeds to cassandra cluster nodes (x.x.x.104-106)... but in general it does not make sense to set it up, since I dont wan't create another node in the Cassandra cluster.
Could you please help me?
Edit: Maybe using something like this might be the correct way?
cassandra-stress user profile=/usr/cassandra/stress-file.yaml ops(insert=1,books=1) n=10000 -node x.x.x.104,x.x.x.105,x.x.x.106 -port native= ?
Telnet [cassandra_node_ip_ddress] 7000 works fine
If you have your Cassandra cluster running with the proper ports open (by default 9042 for clients and 7199 for JMX), and Cassandra directory on a different machine, then you should be able to run cassandra-stress, from outside the cluster, against your cluster simply by passing the -node option with an IP of one of the nodes in your cluster (say x.x.x.104). For example,
$CASSANDRA_HOME/tools/bin/cassandra-stress write -node x.x.x.104
should work. You can see more options with
$CASSANDRA_HOME/tools/bin/cassandra-stress help
on every node:
in cassandra.yaml set rpc_address to IP address
in cassanda-env.sh set LOCAL_JMX=no and jmx options autenticate=false
open firewall port 7199
restart firewall and cassandra
on cassandra-stress server:
cassandra-stress user profile=/usr/cassandra/stress-books.yaml ops\
(insert=1,books=1\)
n=10000 -node 172.16.20.104,172.16.20.105,172.16.20.106 -port native=9042
thrift=9160 jmx=7199
Note! JMX communication is not secured
I have a client that wants to use Tableau on their EMR Spark cluster.
The documentation seems straightforward but I'm getting errors when I try to connect.
Here is the setup:
EMR cluster's master doesn't have a public IP, but from the Tableau desktop EC2 instance I am able to ping and telnet into the port 10001 where thrift is running
I am able to test thrift with beeline and it connects fine
I am not using SSL or authentication given the limit access the cluster has
I have installed both data direct 8.0 and simbaodbc
I'm using emr-5.13.0, the Hadoop distribution is Amazon 2.8.3 and the Spark version is 2.3.0.
The error is
Unable to connect to the ODBC Data Source. Check that the necessary drivers are installed and that the connection properties are valid.
[Simba][ThriftExtension] (5) Error occurred while contacting server: No more data to read.. This could be because you are trying to establish a non-SSL connection to an SSL-enabled server.
Unable to connect to the server "IP". Check that the server is running and that you have access privileges to the requested database."
I simply followed the documentation provided by Tableau which says to install the driver only (not mess with ODBC), then us it in Tableau. I have verified that I have set no SSL and no authentication before trying to connect. I also verified by running Datagrip and doing a query from the Tableau EC2 instance, which works as expected.
resolved the issue by ignoring the documentation and just setting up the odbc driver, then choosing it instead of sparksql as a source.
I am new to Apache Cassandra, i had just install a Apache Cassandra 3.9.0(64-bit) on my local windows 8.1 64- bit laptop along with No-SQL manager for Cassandra.
When i tried to register server an error message displayed as "None of the hosts tried for query are available".
Can anyone help me out.
Thanks.
When I am trying to test a new connection it returns an error:
The specified host(s) could not be reached.
All host(s) tried for query failed (tried: /host_ip:9042 (com.datastax.driver.core.TransportException: [/host_ip:9042] Cannot connect))
[/host_ip:9042] Cannot connect
In my windows firewall, I have already created a rule for DevCenter, which allows DevCenter to communicate with remote Cassandra server. I have no access to Cassandra server but it is configured well, it means that the problem is somewhere on my local computer.
This type of thing typically happens when the host crashes expectantly resulting in the corruption of the sstables or commitlog files.
This is why it is really important to use replication since when you get into this situation you can run nodetool repair to repair the corrupted tables and data from other nodes.
If you are not fortunate enough to have replication configured, then you are in for some data loss. Clear the suspect file from \data\commitlogs, cry a little and restart the node.
I have created 1 node Cassandra cluster (datastax enterprise) on Ubuntu, to which I am able to connect via cqlsh but when i try to connect via OpsCenter or from VS2012 via c# driver I get error like "Unable to connect to cluster" or "All host tried for query are in error", can anyone help me with this error?
EDIT:
I installed the datastax Enterprise following the instructions as given at "datastax.com/documentation/datastax_enterprise/4.0/…; and have all keys with their default value in yaml file except the cluster name. When I run cqlsh it connect with this message:
Connected to fptestcluster at localhost:9160.
[cqlsh 4.1.1 | Cassandra 2.0.6.28 | CQL spec 3.1.1 | Thrift protocol 19.39.0]
But as specified in original question, with OpsCenter and C# driver I am not able to connect.
I found the fix for this, I had to change "listen_address" and "rpc_address" to the IP of machine rather than localhost and then it works, thanks everyone.