I am trying to connect to a remote cassandra database using dbeaver.
I installed cassandra over an ubuntu machine from digital ocean, and I am running the dbeaver from my local machine.
When I leave the default /etc/cassandra/cassandra.yaml file, and then run the netstat -ntlp | grep 9420 I find that the connection is on and waiting for connection but once I update both the listen_address and the rpc_address to the public IP address of the remote machine, I found that I am no longer able to connect even locally to the database, using cqlsh cli.
What are the steps I should do to connect to a remote cassandra database, I read a lot of articles, but obviously there is something missing I can't understand
Related
I can connect my docker postgresql in my local server windows via ip or localhost. When I try to connect it remotely from my personal windows I have timeout error. Thinking about 5432 port is blocked or not listening.
I have changed pg_hba.conf & postgresql.conf files for remote connection and also checked for firewall but it was disabled.
Answer is I should have checked my server's firewall conf also, just dockerVM is not enough :)
I am facing some issues trying to connect to Cassandra 3.3.0 on Centos 7 remotely from another machine in the network. It is returning a "timed out" error while trying to connect via
$ cqlsh 192.168.1.56 9042
Same with:
$ cqlsh 192.168.1.56
In my point of view, I have configured the cassandra.yaml file correctly as it worked fine when I tried to connect to a locally running VM (Ubuntu) with an active Cassandra instance.
When I am checking the IPs and ports which have been bound via netstat -lnt, it is returning
tcp6 0 0 192.168.1.56:9042 :::* Listen
Actually the only one which is bound to tcp6. 192.168.1.56:9160 is bound to tcp.
Running on Ubuntu, it returns the same binding to tcp. So the fault is related to that point, I guess.
Some background facts:
I am running Cassandra as root. Both server and clients are running cqlsh 5.0.1, CQL spec 3.4.0 and Cassandra 3.3.0. Python 2.7.5.
The VM is accessible via 192.168.1.56 without problems. Firewall is deactivated and I even have tried to de- and reactivate IPv6. I have tried different combinations configuring the cassandra.yaml -- such as taking the interface instead of its IP directly, but without changes in the result.
All my research has not shown success so far. Has anybody an idea?!
Problem has been solved due to network misconfiguration.
I've changed the below configuration in /etc/ssh/sshd_config
Port 22
AddressFamily inet
ListenAddress 0.0.0.0
ListenAddress ::
I've changed AddressFamily from "any" to "inet".
I have MongoDB 3.2 installed on my Linux Red Hat server.
I am starting to access it and looking at the mongo Shell instructions.
For a Windows machine, the instructions want me to get to the command prompt and change dirs to the installation directory. The problem is, MongoDB is installed on my web server and not my local windows machine.
Question: does Mongo Shell apply to me then? How do I start using, connecting and accessing Mongo from my Windows and Mac machines?
[Note: I am a traditional MySQL / phpMyAdmin developer looking to advance to MongoDB]
Amendments:
(1) With the help of #AlexBlex I am progressing to trying to connect to my MongoDB on my server from Robomongo on my windows client. I get the following error when trying to setup my connection. I tried the address with just my server ip and with http://{my server ip}. Neither worked. See screen shot of error
(2) This is what I have in my current mongod.conf file:
#port=27017
bind_ip=127.0.0.1
(3) here is what my connection settings look like. Oddly, #AlexBlex's solution below shows an SSH tab on his Mac version. The Windows and Mac versions I just installed lacks that tab.
If you install MongoDB on your local machine, you can use the Mongo shell like below to connect to your remote server
mongo yourserver:27017/database
You will have to configure your Mongo server to allow remote connections. In order to achieve this you need to have the following line in your /etc/mongodb.conf file. You need to replace 10.0.0.2 with the ip address of your client machine.
bind_ip = 127.0.0.1,10.0.0.2
You need either ssh to the server where mongodb is installed, or install mongodb on local machine.
For robomongo to connect to remote host you need to ssh to the server, and check it listens on external interface:
lsof -i | grep 27017
In case it is bound to localhost only, you need to edit a line with bind_ip in /etc/mongodb.conf and restart the service.
I would recommend to keep it listening on the local interface only for security reasons, and use ssh tunnelling to connect:
I found the answer. #ShahNewasKhan is brilliant. See How to connect Robomongo to MongoDB
All you need to do is SSH to server and edit mongod.conf file:
uncomment #port=27017 to port=27017
comment bind_ip=127.0.0.1 to #bind_ip=127.0.0.1
restart mongodb via service mongod restart
Then create a mongo connection via your server ip in the address field and 27017 in the port field
Hope this helps mongo newbies and start-ups like me :) Good luck.
Now I just need to figure out how to make this secure. My concern is that anyone who knows my server ip can hack into my MongoDB
I have a cassandra node at a machine. When I access cqlsh from the same machne it works properly.
But when I tried to connect to it's cqlsh using "192.x.x.x" from another machine, I'm getting an error saying
Connection error: ('Unable to connect to any servers', {'192.x.x.x': error(111, "Tried connecting to [('192.x.x.x', 9042)]. Last error: Connection refused")})
What is the reason for this? How can I fix it?
Probably the remote Cassandra node is not bound to the external network interface but to the loopback one (this is the default configuration). You can ensure this by using "telnet thecassandrahost 9042" from the remote machine, it should not work.
In order to bind Cassandra to the external network interface you need to edit the cassandra.yaml configuration file and set the properties "listen_address" and "rpc_address" to your remote IP or "0.0.0.0" (not all versions of Cassandra support wildcard addresses).
Check also that the firewall is properly configured or disabled (sudo service iptables stop).
Set the config parameter where this file is located. Possibly /etc/cassandra/cassandra.yaml.
cassandra.yaml
listen_address: 192.x.x.x
rpc_address: 192.x.x.x
Then, restart the service.
1.Update：./conf/cassandra.yaml
rpc_address: 0.0.0.0 ("0.0.0.0" allow anywhere IP,but you can appoint an IP)
\# broadcast_rpc_address: 1.2.3.4 (Delete comment if rpc_address=0.0.0.0)
2.restart
./bin/cassandra
Case: I met a problem that I can't remote access cassandra When I using java access cassandra
I got the same issue. And I am following answer in this post. Unfortunately, I have no luck to make it work. I did some research. And it works now. Here is my change.
Environment
Ubuntu Server 16.04.3 LTS on VirtualBox,
DSE version 5.1
Install DSE
I am installing DSE follow this page
https://docs.datastax.com/en/dse/5.1/dse-dev/datastax_enterprise/install/installGUIdse.html
Go to /etc/dse/cassandra/cassandra.yaml
Change 'seeds' from 127.0.0.1 to {seriver ip} exp. mine is 172.20.10.9
listen_address
In DSE 5.1 official document says 'Never specify 0.0.0.0; it is always wrong.'
What I did is comment out 'listen_address' setting
'rpc_address' change from localhost to 0.0.0.0
'broadcast_address' change to server IP. Mine is 172.20.10.9
'broadcast_rpc_address' change to server ip
restart dse wait for couple minute,it is changing. If still not work, restart machine.
This is my log in 15 seconds.
`ubuntu08#ubuntu08:~$ nodetool status
nodetool: Failed to connect to '127.0.0.1:7199' - ConnectException: 'Connection refused (Connection refused)'.
ubuntu08#ubuntu08:~$ nodetool status
Error: The node does not have system_traces yet, probably still bootstrapping
ubuntu08#ubuntu08:~$ nodetool status
Datacenter: SearchGraphAnalytics
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns Host ID Rack
UN 10.0.0.44 278.51 KiB 32 ? 19db0016-df63-4470-9921-f3b5fe4e9341 rack1
`
I can access by run 'cqlsh 172.20.10.9' from local or another machine.
This is another document for Cassandra https://docs.datastax.com/en/developer/java-driver/3.3/manual/address_resolution/
I had the same issue, I was not allowed to listen to 0.0.0.0 and Cassandra was running on a VM with Bridged network. The solution I found was to let the VM SSH to itself, port forwarding the port on the bridged network interface to localhost:
ssh -L 192.168.x.x:9042:127.0.0.1:9042 myvmuser#localhost
Since the IP of the bridged network card would change (depending on which developers machine it was run) the ssh-command had to first get the IP, this snipped worked for that:
ifconfig | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*' | grep -v '127.0.0.1'
Also, as this should happen on boot you have to create a SSH key for the vm-user and trust it via .ssh/authorized_keys.
Even after I set the RPC_ADDRESS, it didn't work for me , until I set the -e CASSANDRA_START_RPC=true option.
It was always set to false in my case. I have tried this with Ubuntu, Docker and Cassandra.
Set the following config parameter in cassandra.yaml file (For CentOS it is located in /etc/cassandra/default.conf)
rpc_address: 0.0.0.0
Verify that following values are same as below(usually they are default)
start_native_transport:true
native_transport_port:9042
Last step for CentOS , Update the firewall configuration and allow port 9042 through for incoming connections
Access the firewall from “System / Administration / Firewall” in the CentOS menu
Add the port under “Other Ports”
I edit cassandra.yaml set listen_address and roc_address as ip address resolve the problem.
OS: CentOS 6.4 (server)
I have successfully installed (yum install dsc20) the cassandra database layer in my server and can connect to it using the CQL SHel (cqlsh). But I need to run queries remotely using the DataStax's DevCenter software. So I installed it (DevCenter) in a separate workstation. (CentOS 6.4 - desktop) and tried to add a new connection in order to connect to the cassandra db.
So I gave the IP of the "CentOS 6.4 - server" (in which cassandra database is running) for the host and the port as 9160. But when testing the connection it fails.
I also tried to turn off the firewall in the server, (/etc/init.d/iptables stop). But was no luck.
I'm sure this may be due to some misconfiguration which I cannot figure out. I'll be grateful, if someone can give me a solution for this as I was researching for this and found no answers. Thank you very much in advance.
DataStax DevCenter being built on top of the DataStax Java driver has the same connectivity requirements as the driver. Namely:
start_native_transport: true
rpc_address: IP or hostname reachable from the client
Machines in the cluster accept connections on port 9042 (the native_transport_port config option)
If rpc_address is set to either a private IP or to 0.0.0.0, DevCenter will not know what node to connect to.
If your cluster has multiple nodes and these are using rpc_address: 0.0.0.0, even if you configure DevCenter with the IP(s) of a couple of nodes, it will still have issues discovering the other nodes in the cluster.
In cassandra.yaml there's a comment/warning about using rpc_address: 0.0.0.0:
Note that unlike ListenAddress above, it is allowed to specify 0.0.0.0
here if you want to listen on all interfaces, but that will break clients
that rely on node auto-discovery.
Note: it is possible that in the future DevCenter might be able to ignore/filter out nodes in the cluster configured with rpc_address: 0.0.0.0.
Try this.. It worked for me!
Run the following command on your machine where you have DevCenter installed
$> ssh -L 9042:localhost:9042 <username>#<ip-address-cassandra-db> -N
After running this command, it will prompt for password
Now in your DevCenter > Contact Hosts, provide "127.0.0.1" and test connection. Bingo, you see the magic...
In the cassandra.yaml, I set
listen_address: localhost
rpc_address: 1.2.3.4
broadcast_rpc_address: 1.2.3.4
After doing a
sudo service cassandra restart
DevCenter was able to successfully connect.
After this change, cqlsh would not start without the address:
cqlsh 1.2.3.4
You can set the environment variable $CQLSH_HOST=1.2.3.4. Then simply type cqlsh.
If there's somebody working with docker locally, it can run this command.
docker run --name cassandra -p 127.0.0.1:9042:9042 -p 127.0.0.1:9160:9160
-e CASSANDRA_LISTEN_ADDRESS=localhost
-e CASSANDRA_BROADCAST_ADDRESS=localhost
-e CASSANDRA_RPC_ADDRESS=localhost -d cassandra