Highly Available ELK (Elasticsearch, Logstash and Kibana) Setup

13 minute read

In this post I will be going over how to setup a complete ELK (Elasticsearch, Logstash and Kibana) stack with clustered elasticsearch and all ELK components load balanced using HAProxy. I will be setting up a total of four six servers (2-HAProxy, 2-ELK frontends and 2-Elasticsearch master/data nodes) in this setup however you can scale the ELK stack by adding additional nodes identical to logstash-1/logstash-2 for logstash processing and Kibana web interfaces and adding the additional node info to the HAProxy configuration files to load balance. You can also scale the Elasticsearch Master/Data nodes by building out addtional nodes and they will join the cluster.

Acronyms throughout article ELK - Elasticsearch Logstash Kibana ES - Elasticsearch

Requirements: In order for all logstash-elasticsearch clustering to work correctly all HAProxy nodes and ELK nodes should be on the same subnet (If not you will need to configure unicast mode for Elasticsearch as multicast is enabled using these scripts). Two Ubuntu (12.04LTS/14.04LTS) HAProxy nodes with two NICS each. (1vCPU and 512MB memory will work) Two or more Ubuntu (12.04LTS/14.04LTS) nodes to install the ELK stack frontends. (2vCPU and 2GB memory will work) Two or more Ubuntu (12.04LTS/14.04LTS) nodes to install the ES Master/Data nodes. (2vCPU and 4GB of memory will work)

IP Addresses required to set all of this up. (Change to fit your environment.) DNS A Record: logstash (with the LB VIP address) (If you use something other than this name update in each location that logstash is configured for. I will be providing a script to do this in the near future.)

  • LB VIP 10.0.101.60
  • haproxy-1 10.0.101.61
  • haproxy-2 10.0.101.62
  • logstash-1 10.0.101.185
  • logstash-1 172.16.0.1 (Cluster Heartbeat)
  • logstash-2 10.0.101.180
  • logstash-2 172.16.0.2 (Cluster Heartbeat)
  • es-1 10.0.101.131
  • es-2 10.0.101.179

If you decide to use different node names than the above list then you will need to make sure to make changes to the configurations to reflect these changes.

HAProxy Nodes (haproxy-1, haproxy-2): Setup both HAProxy nodes identical all the way down to the ELK stack setup section. The below instructions which have been crossed out are no longer valid but will remain in the off chance that you would like to use heartbeat instead of keepalived for your cluster setup.

First thing we need to do is install all of the packages needed.

sudo apt-get install haproxy heartbeat watchdog

Now we will need to configure networking on each nodes as follows. (Again modify to fit your environment.)

sudo apt-get install haproxy keepalived

HAProxy-1 (Primary)

sudo nano /etc/network/interfaces

Overwrite the contents with the code from below.

HAProxy-2 (Failover)

sudo nano /etc/network/interfaces

Overwrite the contents with the code from below.

We need to allow an interface to be brought online that is not part of the /etc/network/interfaces configuration so we need to run the following. This will allow all of our VIP’s to come up.

echo "net.ipv4.ip_nonlocal_bind=1" >> /etc/sysctl.conf

Verify that the above setting has been set by running the following on each node. You should get back the following net.ipv4.ip_nonlocal_bind = 1

sysctl -p

Now you will need to restart networking on each node or reboot for the IP settings from above to be set. sudo service networking restart Now we are ready to configure our heartbeat service on each node. We will do that by setting up the following configuration files on each node.

sudo nano /etc/ha.d/ha.cf

Copy the following into ha.cf file.

sudo nano /etc/ha.d/authkeys

Copy the following into authkeys (change password to something else).

auth 3
1 crc
2 sha1 password
3 md5 password

Now change the permissions of the authkeys as follows.

sudo chmod 600 /etc/ha.d/authkeys

Now we will create the haresources file to complete the heartbeat service setup.

sudo nano /etc/ha.d/haresources

Copy the following into haresources.

haproxy-1 IPaddr::10.0.101.60/24/eth0 logstash

Now we need to configure the keepalived cluster service. All that we need to do is create /etc/keepalived/keepalived.conf

sudo nano /etc/keepalived/keepalived.conf

And copy the contents from below and save the file. Make sure to modify the IP addresses to match your environment.

Now you need to start the keepalived service

sudo service keepalived start

You can check and make sure that all of your VIP’s came up by running the following. A normal ifconfig will not show them.

sudo ip a | grep -e inet.*eth0

You should see something similar to below.

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Now we are ready to setup HAProxy for our ELK stack. The final piece of our setup for frontend load balancer cluster.

sudo nano /etc/haproxy/haproxy.cfg

Replace all contents in haproxy.cfg with the following code.

Now we need to set HAProxy to enabled so it will start.

sudo nano /etc/default/haproxy

Change

ENABLED=0

to

ENABLED=1

Now we should be able to start HAProxy up.

sudo service haproxy start

If you see errors similar to below these can be ignored.

[WARNING] 153/132650 (4054) : config : 'option httplog' not usable with proxy 'logstash-syslog-514' (needs 'mode http'). Falling back to 'option tcplog'.
[WARNING] 153/132650 (4054) : config : 'option httplog' not usable with proxy 'logstash-syslog-1514' (needs 'mode http'). Falling back to 'option tcplog'.
[WARNING] 153/132650 (4054) : config : 'option httplog' not usable with proxy 'logstash-eventlog' (needs 'mode http'). Falling back to 'option tcplog'.
[WARNING] 153/132650 (4054) : config : 'option httplog' not usable with proxy 'logstash-iis' (needs 'mode http'). Falling back to 'option tcplog'.
[WARNING] 153/132650 (4054) : config : 'option httplog' not usable with proxy 'logstash-redis' (needs 'mode http'). Falling back to 'option tcplog'.
[WARNING] 153/132650 (4054) : config : 'option httplog' not usable with proxy 'elasticsearch' (needs 'mode http'). Falling back to 'option tcplog'.
[ OK ]

Now one last thing to do based on the fact that HAProxy cannot load balance UDP ports and not all network devices have the option to send their syslog data to a TCP port. We will install an instance of Logstash and setup rsyslog forwarding on each HAProxy node. This instance will only listen for syslog on the standard UDP/514 port, do some filtering and join the logstash-elasticsearch cluster as a client and output to this cluster. be configured to monitor the nginx logs and forward them back to the logstash cluster using redis. We will be configuring rsyslog to listen on UDP/514 and forward to the logstash cluster over TCP/514. I have made this extremely easy by running a script. However do not run this until after you have setup your ELK stack nodes below. If you do set this up prior to building out your ELK nodes then you will need to restart the logstash service on each of your haproxy nodes. If for some reason you need to restart the logstash service you can do so by running.

sudo service logstash restart

So let’s setup our logstash instance and configure rsyslog forwarding. To do so run the following commands in a terminal session on each of your HAProxy nodes.

sudo apt-get install git
cd ~
git clone https://github.com/mrlesmithjr/Logstash_Kibana3
chmod +x ./Logstash_Kibana3/Cluster_Setup/Logstash-HAProxy-Node.sh
sudo ./Logstash_Kibana3/Cluster_Setup/Logstash-HAProxy-Node.sh

If you copied the haresources file exactly from above then Logstash will only be running on the active cluster node and will start on the failover node when a failover occurs.

Now HAProxy node1 is complete make sure to do all of the above on your HAProxy node2 and make sure to change the priority as noted in the keepalived.conf file. Once you have completed HAProxy node2 continue onto the next section of setting up your ELK stack. You could also clone the first node to create the second node but if you do; make sure to make the proper change in keepalived.conf and haproxy.cfg as above.

ES (Elasticsearch Master/Data Nodes (es-1, es-2): Now we will be setting up our two nodes to build our Elasticsearch cluster and again I have a script to do this. These nodes will only be Master/Data nodes. They will not be doing any logstash processing. They will purely be used to maintain the cluster and provide redundancy. These nodes will not be exposed to the HAProxy Load Balancers; Only our ELK nodes below will be. These nodes will process all of the data that our frontend ELK nodes send back to be ingested, indexed and etc. For now we will only be setting up two ES Master/Data nodes; however you can build out as many as you like and use this same script each time for each additional node (If you add more than two you will want to adjust the following parameter in /etc/elasticsearch/elasticsearch.yml to ensure you do not experience a split-brain ES cluster. You will set the value to n/2+1 where n=number of nodes. So for example with just two nodes it would be 1 (or not set); whereas with 3 the value would be 2 (3/2+1=2)). Just make sure that every node-name is unique and has a DNS record associated with it.

discovery.zen.minimum_master_nodes: 2

So let’s get these nodes up and running. On your new ES nodes run the following script on each to get them running.

sudo apt-get install git
cd ~
git clone https://github.com/mrlesmithjr/Logstash_Kibana3
chmod +x ./Logstash_Kibana3/Cluster_Setup/Logstash-ES-Cluster-Master-data-node.sh
sudo ./Logstash_Kibana3/Cluster_Setup/Logstash-ES-Cluster-Master-data-node.sh

Once these are up and running your new ES cluster (logstash-cluster) should be ready to go. However you will want to modify your Java Heap Size to 50% of the installed memory. So if you installed per the requirements you will want to adjust the ES_HEAP_SIZE to 2g because by default it will be at 1g. And it is commented out by default.

sudo nano /etc/init.d/elasticsearch

change

#ES_HEAP_SIZE=1g

to

ES_HEAP_SIZE=2g

Now proceed onto setting up the frontend ELK nodes.

ELK (Elasticsearch, Logstash and Kibana) Nodes (logstash-1, logstash-2):

Now we are ready to set up our ELK frontend nodes and again I have a script to make this process repeatable and simple. For now we will only be setting up two ELK nodes; however you can build out as many as you like and use this same script each time for each additional node. Just make sure that every node-name is unique and has a DNS record associated with it.

So to get started all you need to do is run the following on a fresh Ubuntu 12.04LTS/14.04LTS server. And let the script setup your ELK node. Again this script will install Elasticsearch and join the “logstash-cluster” with master capabilities and as a data node as a client node, install Logstash with many different filtering patterns and inputs; as well as join the “logstash-cluster” as a client node (From logstash output - so yes; 2 instances per ELK node will show as clients in the ES cluster) to output all logs to and install the Kibana3 webUI configured to read from the “logstash-cluster”. These ELK nodes will do all of the heavy lifting for logstash processing as well as servicing Kibana requests meanwhile keeping that load off of the ES Master/Data nodes from above (allowing them to do nothing more than churn data).

So all that is left to do once this is done is to start pointing your network devices to the HAProxy VIP (10.0.101.60 or logstash) for syslog and watch the data start flowing in.

sudo apt-get install git
cd ~
git clone https://github.com/mrlesmithjr/Logstash_Kibana3
chmod +x ./Logstash_Kibana3/Cluster_Setup/Logstash-ELK-ES-Cluster-client-node.sh
sudo ./Logstash_Kibana3/Cluster_Setup/Logstash-ELK-ES-Cluster-client-node.sh

Once this has been completed make sure to go back up at the end of the HAProxy setup and install the logstash instance on each node. Once that has been completed you can begin to test out with only one ELK node or you can build out a few more ELK nodes if you like. I would at least start with two to get the full benefit of this setup.

**NOTE** If you used different naming for your VIP hostname other than logstash you will need to modify the following file on on each of your ELK Client nodes for the Kibana web interface to connect to ES correctly. You can do that by doing the following and replacing logstash with your viphostname used for your setup…(example myloghostname) Edit /usr/share/nginx/html/kibana/config.js and change http://logstash:9200 to http://yourviphostname:9200

sudo nano /usr/share/nginx/html/kibana/config.js

Or you can do the following but replace yourviphostname with the actual VIP hostname used for your setup

sed -i -e 's|^elasticsearch: "http://logstash:9200",|elasticsearch: "http://yourviphostname:9200",|' /usr/share/nginx/html/kibana/config.js

Now all that is left to do is configure your network devices to start sending their syslogs to the HAProxy VIP and if your device supports sending via TCP, use it. Why use it? Because you will benefit from the load balancing of the TCP connections and there will not be any lost events (UDP - Best effort, fast!, TCP - Guaranteed, slower; but this type of setup will bring great results!)

Reference the port list below on configuring some of the devices that are pre-configured during the setup.

Port List TCP/514 Syslog (Devices supporting TCP) UDP/514 Syslog (Devices that do not support TCP - These are captured on the HAProxy nodes and shipped to logstash using redis) TCP/1514 VMware ESXi TCP/1515 VMware vCenter (Windows install or appliance) (For Windows install use NXLog from below in device setup) (For appliance reference device setup below) TCP/3515 Windows Eventlog (Use NXLog setup from below in device setup) TCP/3525 Windows IIS Logs (Use NXLog setup from below in device setup)

Device Setup For Windows (IIS,Eventlog and VMware vCenter logging) install nxlog and use the following nxlog.conf file below to replace everything in C:\Program Files (x86)\nxlog\conf\nxlog.conf\

For VMware vCenter appliance do the following from the appliance console.

vi /etc/syslog-ng/syslog-ng.conf

Now add the following to the end of the syslog-ng.conf file

source vpxd {
       file("/var/log/vmware/vpx/vpxd.log" follow_freq(1) flags(no-parse));
       file("/var/log/vmware/vpx/vpxd-alert.log" follow_freq(1) flags(no-parse));
       file("/var/log/vmware/vpx/vws.log" follow_freq(1) flags(no-parse));
       file("/var/log/vmware/vpx/vmware-vpxd.log" follow_freq(1) flags(no-parse));
       file("/var/log/vmware/vpx/inventoryservice/ds.log" follow_freq(1) flags(no-parse));
};

# Remote Syslog Host
destination remote_syslog {
       tcp("logstash" port (1515));
};
#
# Log vCenter Server vpxd log remotely
log {
        source(vpxd);
        destination(remote_syslog);
};

Now restart syslog-ng

/etc/init.d/syslog restart

For Linux (Ubuntu, etc.) I prefer rsyslog as it is installed by default on most.

sudo nano /etc/rsyslog.d/50-default.conf

Now add the following to the end of this file

*.* @@logstash

Note the ”@@” this means use TCP; whereas “@” means use UDP.

Now that your setup is complete you can browse to the Kibana webUI by using your browser of choice and go here.

2014-06-07_22-06-43

You should see some logs showing up here now but the view is not that great or usable so you will need to start building how you want your dashboard to look. Or you can use some of the dashboards I have created by clicking the load folder at the top right and go to advanced and enter the gist number or url by using the gist url’s below (copy and paste the https://url). Once you load the dashboard make sure to save it or it will be gone once you browse away.

Apache:

Windows IIS:

Nginx:

PFsense Firewall:

Syslog:

VMware:

Windows:

To view your Elasticsearch Elastic HQ plugin go here.

2014-06-07_22-40-07

To view the Elasticsearch Paramedic plugin go here.

2014-06-07_22-46-47

To view the Elasticsearch Head plugin go here.

2014-06-07_22-48-38

To view the Elasticsearch Marvel plugin go here.

2014-06-07_22-50-20

To view your HAProxy stats go here. (Login with admin/admin)

2014-06-07_22-56-07

So there you have it. A highly available ELK setup which also allows us to scale out extremely easy and is repeatable.

While I have been going through this setup and testing out different components brought to light many other options for HAProxy and the ideas behind this post so stay tuned to more soon. As well as I will be providing a visio drawing of the layout. I am also working on some scripts to setup a proxy (nginx) in front of kibana for ssl password protection to login and to redirect ES queries through the proxy; as well as some scripts to do IPTables firewall configurations to tighten down access into the ES nodes forcing access through the nginx proxy and HAProxy Load Balancers mitigating access directly to an ES node. This will all be in a follow up post very soon.

Follow up posts

Setup all ELK components to work in unicast mode instead of mutlicast discovery mode.

Here is a quick screenshot of performance from the marvel plugin just for reference. Only processing about 6GB/Day right now.

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And the Visio drawing to represent the components.

ELK-Stack-HA

Enjoy!

Need help with your ELK Stack deployments? Head over here and see how we can help.

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If you are looking for a way of deploying this using Ansible head over here.

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