I have a two-node Liferay 7.1 cluster. I manually restarted an OSGI module via Felix and noticed that only one of the two nodes has any logs about it.
The module in question does not work, or fail, as intended (hence the restarting) and I want to cover all my bases. Do OSGI modules run on all nodes, or are they split between nodes in Liferay 7.1?
You have to deploy modules to both the nodes. They have to be active and running on both the nodes. Please check and make sure that you have the module deployed to both and test.
Hope this helps.
Related
Anybody supporting a Cassandra application in production? Curious to know about, how you handle cassandra.yaml file. Also, do you think "seed node" get's a status of master node (partially).
Anybody supporting a Cassandra application in production?
Yes, my team supports several applications which use Cassandra in production.
Curious to know about, how you handle cassandra.yaml file.
By "handle" the cassandra.yaml file, I assume you mean deploy with different values with automation at large scale. We use an open source tool called Rundeck for that.
Rundeck allows you to build options into your jobs, which is useful for properties like cluster_name, seeds, etc. Then, you inject those options into your deploy scripts, using a regex replace (sed) to get them into specific properties in the yaml. Ex:
sed -i "s/cluster_name: 'Test Cluster'/cluster_name: '#cluster_name#'/" cassandra.yaml
Also, do you think "seed node" get's a status of master node (partially).
No, a seed node is not any kind of "master" node.
A seed node is no different from any other node.
In theory, every node in your cluster could be a seed node for another node. All it is, is a way for a new node to discover the network topology of the cluster. Think of it as an entry point to the cluster.
Building a Thingsboard cluster
I need help setting up a Thingsboard cluster, the documentation online is very limited.
The cluster will contain 2 Zookeeper nodes and 4 Thingsboard nodes with Cassandra DB.
Should Zookeeper be installed separately?
A step-by-step guide would be much appreciated!
I cannot provide you detailed step-by-step instructions to setup a ThingsBoard cluster. I can point you into the right direction by sharing the different documents you need to do so.
Bottom line, the following tasks must be completed:
Install and configure a ZooKeeper ensemble.
Check the ZooKeeper documentation for further installation details. Keep in mind that you need at least three different ZK-nodes in a clustered environment and that you always need an odd number of ZK nodes (3,5,7,...). It is a very very very bad idea to build a cluster consisting out of two ZK-nodes, check split brain condition that might appear under these circumstances! Basically you setup the number of individual nodes you wish to use and change the configuration file to enable the different nodes as an ensemble. This is documented quite well in the ZK-docs.
Install and configure a Cassandra cluster.
Again you will setup the number of individual nodes you need for your Cassandra cluster and modify the individual configuration files to convert them into a Cassandra cluster. Check Cassandra documentation for details. Be sure to check proper configuration using the nodetool status command as described at the end of the document. All your nodes should be up and running.
Install and configure a ThingsBoard cluster.
Use the instructions provided with ThingsBoard single node setup.
Install Java
Skip External database installation
ThingsBoard service installation
Configure ThingsBoard to use the external database - Cassandra
Go to Cluster setup and apply the configuration steps depicted (ZK, Cassandra and RPC). Keep in mind to point to ALL members of your ZK, Cassandra cluster. You can also use IP-addresses instead of host names.
Return to single node setup and run the installation script at ONE NODE only!
Start ThingsBoard service
If everything went well, you should be able to access your ThingsBoard nodes directly using the URL http://[NODE_IP]:8080. You can verify proper cluster operation by creating a tenant on one node and check its presence on another node.
I don't know if using an even number of ThingsBoard nodes is a good idea. The documentation does not mention anything about this.
One final remark, you could/should consider putting a proxy in front of your ThingsBoard cluster to provide load balancing to your web clients and improve user experience. This way you shouldn't share the individual host addresses with your users and you will prevent node overloading due to the fact that everybody is using the same web-address to access your dashboard(s). You could also proxy your MQTT broker to provide load balancing as well.
Good luck in setting up your cluster!
Zookeeper needs at least 3 nodes to run in a cluster mode. Each node voting and the valid replica count to gain the QUORUM is 3.
I am trying to deploy Cassandra on a Linux Based HPC cluster and I need some guidelines if possible. Specifically, what is the difference between running Cassandra locally and in cluster.
When managing locally (in which case it runs smoothly) we duplicate the original files for every node inside our Cassandra directory and we apply the appropriate changes for IP address, rcp, JMX etc... however, when managing a network which files do we need to install in each node. The whole package with all the files or just some of the required ones
like, bin/cassandra.in.sh, conf/cassandra.yaml, bin/cassandra.
I am a little bit confused on what to store in each node separately so to start working on the cluster.
You need to install Cassandra on each node (VM), i.e. the whole package and then update config files as neccessary. As described here to configure cluster in a single data center you need:
Install Cassandra on each node
Configure cluster name
Configure seeds
Configure snitch, if needed
I am using Icinga2-2.3.2 cluster HA setup with three nodes in the same zone and database in a seperate server for idodb. All are Cent OS 6.5. Installed IcingaWeb2 in the active master.
Configured four local checks for each node including cluster health check as described in the documentation. Installed Icinga Classi UI in all three nodes, beacuse I am not able to see the local checks configured for nodes in Icinga Web2.
Configs are syncing, checks are executing & all three nodes are connected among them. But the configured local checks, specific to the node alone are not happening properly and verified it in the classic ui.
a. All local checks are executed only one time whenever
- one of the node is disconnected or reconnected
- configuration changes done in the master and reload icinga2
b. But after that, only one check is hapenning properly in one node and the remaining are not.
I have attached the screenshot of all node classic ui.
Please help me to fix and Thanks in advance.
I have 4 windows machines, On which i have installed hadoop on 3 out of 4.
One machine having the Harton work Sandbox ( say for 4-th machine) , Now i need to make the 4th machine as my server ( Name node )
and rest of the machine as slaves.
Whether it will work if i update the configuration files in the rest of 3 machines
Or is there any other way to do this ?
Any other suggestions ?
Thanks
finally i got this but i could not find any help
Hadoop cluster configuration with Ubuntu Master and Windows slave
A non-secure cluster will work (non-secure in the sense that you do not enable Hadoop Kerberos based auth and security, ie. hadoop.security.authentication is left as simple). You need to update all nodes config to point to the new 4th node as the master for various services you plan to host on it. You mention namenode, but I assume you really mean to make the 4th node the 'head' node, meaning it will probably also run resourcemanager and historyserver (or the jobtracker for old-style Hadoop). And that is only core, w/o considering higher level components like Hive, Pig, Oozie etc, and not even mentioning Ambari or Hue.
Doing a post-install configuration of existing Windows (or Linux, makes no difference) nodes is possible, editing the various xx-site.xml files. You'll have to know what to change and is not trivial. Probably it would be much easier to just deploy again the windows machines, with an appropriate clusterproperties.txt config file. See Option III - Manual Install One Node At A Time.