Datastax Agent (Cassandra) Opscenter setup issue

0
votes

I've setup opscenter on one of cassandra cluster nodes. After installation, when setting up my cluster, I tried installation of datastax agent on all the cluster nodes via UI, but it failed. So, I had to install the agents manually.

After manually installing the agents, the node in which opscenter is installed is able to connect, but not the other nodes. It still says, "2 agents failed to connect". What could be the issue?

PS : My cassandra cluster is setup on AWS in ubuntu

My agent.log file looks like this

 ERROR [os-metrics-9] 2015-07-27 07:04:43,390 Long os-stats collector failed: Cannot run program "iostat": error=2, No such file or directory
 ERROR [os-metrics-7] 2015-07-27 07:04:43,391 Long os-stats collector failed: Cannot run program "iostat": error=2, No such file or directory
 ERROR [os-metrics-8] 2015-07-27 07:04:53,391 Long os-stats collector failed: Cannot run program "iostat": error=2, No such file or directory
 ERROR [os-metrics-3] 2015-07-27 07:04:53,392 Long os-stats collector failed: Cannot run program "iostat": error=2, No such file or directory
 ERROR [StompConnection receiver] 2015-07-27 07:05:02,946 failed connecting to **.**.**.**:61620:java.net.ConnectException: Connection timed out
5
amazon-web-servicescassandracassandra-2.0datastaxopscenter

5 Answers

3
votes

You have to set the stomp_interface in the address.yaml like 

stomp_interface: <ip-address>

After agent restart it should be connected.

3
votes

As your agent have been able to connect from the same box where opscenter is installed, so it sounds like :

  1. You might have not configured your firewall properly. If you please try by disabling firewall on all your boxes.
  2. You may have multiple interfaces and C* installation picked up an undesired interface. So run ifconfig or ip command on all of your instances and check with C* yaml.
  3. About iostat failure message : You have not install sysstat pkg. Seems, you have not install dependencies as part of DSE install.
3
votes

The agents uses iostat to collect some information from disks. If it cant find it you will get that error but it just means those metrics will be missing some os metrics (likely a lot of disk and cpu metrics will be missing)

0
votes

These are some useful configurations that you should keep in mind when starting the agent manually in the conf/address.yaml file:

###A name for the node to use as a label throughout OpsCenter.
alias: 

###Reachable IP address of the opscenterd machine. The connection made will be on stomp_port. Internal IP in this case
stomp_interface: 

###Port for the agent's HTTP service (default: 61621). 
#api_port: 61621

###The stomp_port used by opscenterd. == Must match with the 'incoming_port' in opscenter.conf 
stomp_port: 61620

###The IP used to identify the node.
local_interface: 100.73.158.44

###The IP that the agent HTTP server listens on. 
agent_rpc_interface: 

###Host used to connect to local JMX server. 
jmx_host: 100.73.158.44

###Whether or not to use SSL communication between the agent and opscenterd.
use_ssl: 1
0
votes

To solve the "Cannot run program 'iostat'" error, do this:

sudo apt-get install sysstat