Difference between revisions of "Splunk"

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Splunk is a flexible data aggregation system.  In laymens' words, Splunk is a system that combs through log files (and anything else that contains structured information that you want to throw at it) and presents the results in a summarized format. It is really a pretty neat thing. See the [http://www.splunk.com splunk website].
 
Splunk is a flexible data aggregation system.  In laymens' words, Splunk is a system that combs through log files (and anything else that contains structured information that you want to throw at it) and presents the results in a summarized format. It is really a pretty neat thing. See the [http://www.splunk.com splunk website].
  
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== Splunk 4.3 ==  
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== Splunk at NPG ==
  
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We are currently in the process of reconfiguring our (now not completely working) Splunk setup with version 4.3. This configuration will utilize the new Universal Forwarders which are more lightweight and have a smaller overall footprint than the older light forwarder configuration. This space will contain my notes while migrating and eventually will replace the older Splunk configuration information once the new system is complete.
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At NPG we have the following setup:
  
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The following links are the Splunk documentation resources about configuring a main indexer and light forwarders. I will eventually summarize the steps here.
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Taro  = Splunk indexer, splunk deployment server, splunk web server
  
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[http://www.splunk.com/download/ Download Splunk]
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Endeavour, Gourd, Einstein, Roentgen, Lentil, ... = Splunk forwarding servers.
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[http://www.splunk.com/download/universalforwarder Download Universal Forwarder]
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[http://docs.splunk.com/Documentation/Splunk/latest/Installation/InstallonLinux Install on Linux]
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So, the other systems all forward their data to Taro, where it is indexed. The instructions of what to do by these forwarding hosts is also provided by Taro (deployment server).
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[http://docs.splunk.com/Documentation/Splunk/4.3/Deploy/Deployanixdfmanually Deploy *nix Universal Forwarder]
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Additional indexing of data can be implemented by adding data to the deployment class on Taro. You can also add data directly on the node by editing the config files.
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[http://docs.splunk.com/Documentation/Splunk/latest/Admin/Changedefaultvalues#Changing_the_admin_default_password Change Admin pw from command line]
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http://docs.splunk.com/Documentation/Splunk/latest/Data/MonitorfilesanddirectoriesusingtheCLI Add files to monitor from command line]
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Note: This means that even if you start the web interface on one of the other nodes, you won't see anything, since all the data was send to Taro.
 +
 
 +
== Splunk 6.2.x ==
 +
 
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We are currently using Splunk version 6.2.2, which will be upgraded only as needed.
 +
 
 +
== Accessing Splunk ==
  
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== Splunk at UNH ==
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The splunk web interface is available via port 8000 on Taro. This port is not open on the firewall so an ssh port forward should be used to access it. To do so use the following command:
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We are now (December 2009) running the free 4.0.7 on our systems: [[Pumpkin]], [[Taro]], [[Gourd]], [[Endeavour]], [[Einstein]], [[Tomato]], [[Improv]]. If it is not running on one of these systems, it should be. Splunk is no longer as resource hungry as before. On systems where the splunk system is starting to use too much resources we can reconfigure the splunk layer as a lightweight forwarder. Currently [[Pumpkin]] is set up as a receiver and [[Endeavour]] as a duplicate receiver.
 
  
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Our setup:
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ssh -L 8001:localhost:8000 username@pumpkin
  
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* Splunk runs on servers, with [[Pumpkin]] the master (receiver) node.
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Then direct your browser to https://localhost:8001  (you can change the 8001 to anything you want on both commands.)
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* On Pumpkin, it is installed in /data1/splunk, with a link to /opt/splunk. This should be fairly consistent among systems.
 
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* Pumpkin mounts the /var/log directories from [[Roentgen]] so that it can be accessed by splunk for aggregation, without the need to run a splunk copy on roentgen (which is virtual).
 
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* Splunk runs on [[Endeavour]] as a full server, on [[Einstein]],[[Taro]],[[Pepper]], [[Gourd]], [[Tomato]] and [[Improv]] it depends, it may run as forwarding server.
 
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* The free version of splunk does not allow for login. We restrict access to the splunk console in iptables. Use an ssh tunnel to access the splunk web portal.
 
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* This can be extended to do many different tasks!
 
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* The new >4 versions of Splunk come with applications. We run the *Nix application, which does a nice job of giving a sense of what is happening on Unix like systems.
 
  
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== Connecting to Splunk ==
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IF we are still using an "enterprise" license, you will be asked to enter a user name and password. Try "admin" and "changeme" or "splunkitnow"
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Pumpkin blocks all port 80 and port 8000 connections in the iptables, so it's not possible to access the interface to Splunk by simply opening a web browser and going to the appropriate port. This is a safety issue, so it is not going to change. There is a fairly simple workaround, you can open an ssh tunnel:
 
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# <code>ssh -L8001:localhost:8000 pumpkin</code>. It doesn't necessarily have to be 8001, but some non-priviledged available port on your machine.
 
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# Open a web browser with good Javascript support and Flash 10 or later, and go to ''localhost:8001'' (or whatever port you chose). On Linux and OS X only Firefox is compatible. On Windows IE is compatible as well (but you won't care, right?)
 
  
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== Sophisticated stuff for Splunk ==
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== Using Splunk ==  
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You can use the admin button on the splunk web interface to do administration, add a user account (licensed version only), add new input streams. This is pretty simple. More sophisticated use is documented here: [http://www.splunk.com/ Splunk.com] then go to documentation and click on the version used.
 
  
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A good place to start when using splunk is the "search". There are saved searches, which allow you to start exploring. Some of the saved searches are exported as dashboard apps.
  
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Click on "Dashboards" in the green bar on the top. Then choose a dashboard (i.e. "Errors last 24h") and click the title. The resulting bar graph shows the errors color coded by machine. You can now click on the colored bars to explore what these errors were and then '''take action'''.
  
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= OLD Config things from version 3 =
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== Installing Splunk ==
  
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These may or may not work anymore, but are saved here for documentation history.
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This is changing with every release, fortunately it get easier.  
  
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=== Filtering the input files ===
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On Taro, Splunk is installed on /data/splunk/splunk-xxx  with a link to the latest version. Taro also hosts the tar file.
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See [http://www.splunk.com/doc/3.1.1/admin/adminfilewhiteblacklist Splunk File whitelist/blacklist].
 
  
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We usually just let splunk loose on an entire directory (/var/log) of several machines (einstein, roentgen, pumpkin...). There are files splunk will skip automatically (mostly binaries). Others can be filtered out by editing /opt/splunk/etc/bundles/local/inputs.conf and adding a line like:
 
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_blacklist = audit\.log|\.[12345]  # Ignore the audit files, which you should read with aureport anyhow.
 
  
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You can see what the input files splunked will be with:
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=== Adding Forwarders ===
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. /opt/splunk/bin/setSplunkEnv
 
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/opt/splunk/bin/listtails
 
  
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=== Splunk getting sysinfo from other nodes ===
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The process for installing a forwarder is pretty simple. Forwarders don't have a web interface, we turn it off, so use the following commands:
  
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'''This is discontinued.''' Too much ssh connections, causes lots of entries in log files, which is no good since it obfuscates what happens and ssh is important!
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# cd /opt        # (or /data for systems with a data drive)
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# mkdir splunk
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# cd splunk
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# tar xzvf /net/data/taro/splunk/splunk-xxxx.tgx
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# cd splunk
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# bin/splunk start  ## (agree to license)
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# bin/splunk edit user admin -password splunkitnow -role admin -auth admin:changeme
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# bin/splunk set deploy-poll 10.0.0.247:8089  ## (set deployment server as Taro)
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# bin/splunk enable boot-start
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# bin/splunk disable webserver
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# bin/splunk restart
  
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To get sysinfo (cpu load, users logged in, memory useage) from other nodes, without running splunk everywhere and without creating huge log files with this info everywhere, I made a "pipe" for splunk. This is a script that runs on splunk in $SPLUNKHOME/etc/bundles/sysinfo that will ssh over to each node monitorred and execute the command /root/splunk_ssh_info_pipe.
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That's all folks.
  
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To make this whole thing secure, I did the following:
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== Documentation ==
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* Modify the /root/.ssh/authorized_keys to have an entry that will only execute one command when jalapeno tries to connect to the node (pepper, taro,...) with a passwordless ssh connection. This command is our pipe script:
 
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no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty,from="jalapeno.farm.physics.unh.edu",command="/root/splunk_ssh_info_pipe" ssh-rsa verylongsshkeyishere root@jalapeno.unh.edu
 
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* This will only work is root is allowed to connect like this, so I modified /etc/security/access.conf to allow a root login from jalapeno.
 
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* The script when run on the node creates output that is then parsed by splunk.
 
  
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This is fairly secure. I could have created a used "splunk" for all machines and set it up so that that user can only execute one command. Perhaps I'll switch to that at some point.
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These links are useful references when setting up Splunk.  
  
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== Getting Splunk to run on a new node ==
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[http://www.splunk.com/download/ Download Splunk]
  
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Install splunk by untarring the install tar file, currently located at /net/data/pumpkin1/splunk <br>
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[http://docs.splunk.com/Documentation/Splunk/latest/Updating/Extendedexampledeployseveralstandardforwarders Example Deployment server]
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Standard location is /opt, move the resulting /opt/splunk to /opt/splunk-<version> and make a soft link to splunk. <br>
 
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Now start up the system:
 
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  /opt/splunk/bin/splunk start --accept-license
 
  
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Next, startup "firefox localhost:8000" or tunnel to the splunk web server. <br>
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[http://docs.splunk.com/Documentation/Splunk/6.2.3/Updating/Configuredeploymentclients  Configure Deployment Clients (CLI examples)]
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Next go to admin tab:
 
  
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# (Optional) Turn on the SSL
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[http://docs.splunk.com/Documentation/Splunk/latest/Installation/InstallonLinux Install on Linux]
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# Setup the logs to watch: data input -> files & directories  -> New Input. Then add /var/log.
 
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# Setup forwading to pumpkin.farm.physics.unh.edu port 8089. Do not store local data (usually).
 
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# Run bin/splunk disable webserver (or the splunk/etc/system/local/web.conf set "startwebserver=0" to turn off the local web server.)
 
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# Restart server: bin/splunk restart
 
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# Make splunk start automaticalle: bin/splunk enable boot-start
 
  
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Wow, you're done!
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[http://docs.splunk.com/Documentation/Splunk/4.3/Deploy/Deployanixdfmanually Deploy *nix Universal Forwarder]
  
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= LAYOUT =
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[http://docs.splunk.com/Documentation/Splunk/latest/Admin/Changedefaultvalues#Changing_the_admin_default_password Change Admin pw from command line]
  
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Current setup:  
+
[http://docs.splunk.com/Documentation/Splunk/latest/Data/MonitorfilesanddirectoriesusingtheCLI Add files to monitor from command line]
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* Pumpkin is the master collector.
 
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* Endeavour stores local and sends to Pumpkin.
 
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* Einstein sends to Pumpkin AND Endeavour, no local store.
 
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* Taro sends to Pumpkin, no local store.
 
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* Improv sends to Pumpkin, no local store.
 
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* Pepper sends to Pumpkin, no local store.
 
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* Roentgen is sucked directly out of /var/log through a mount on Pumpkin.
 

Latest revision as of 14:30, 14 May 2015

Splunk is a flexible data aggregation system. In laymens' words, Splunk is a system that combs through log files (and anything else that contains structured information that you want to throw at it) and presents the results in a summarized format. It is really a pretty neat thing. See the splunk website.

Splunk at NPG

At NPG we have the following setup:

Taro = Splunk indexer, splunk deployment server, splunk web server

Endeavour, Gourd, Einstein, Roentgen, Lentil, ... = Splunk forwarding servers.

So, the other systems all forward their data to Taro, where it is indexed. The instructions of what to do by these forwarding hosts is also provided by Taro (deployment server). Additional indexing of data can be implemented by adding data to the deployment class on Taro. You can also add data directly on the node by editing the config files.

Note: This means that even if you start the web interface on one of the other nodes, you won't see anything, since all the data was send to Taro.

Splunk 6.2.x

We are currently using Splunk version 6.2.2, which will be upgraded only as needed.

Accessing Splunk

The splunk web interface is available via port 8000 on Taro. This port is not open on the firewall so an ssh port forward should be used to access it. To do so use the following command: 

ssh -L 8001:localhost:8000 username@pumpkin

Then direct your browser to https://localhost:8001 (you can change the 8001 to anything you want on both commands.)

IF we are still using an "enterprise" license, you will be asked to enter a user name and password. Try "admin" and "changeme" or "splunkitnow"

Using Splunk

A good place to start when using splunk is the "search". There are saved searches, which allow you to start exploring. Some of the saved searches are exported as dashboard apps.

Click on "Dashboards" in the green bar on the top. Then choose a dashboard (i.e. "Errors last 24h") and click the title. The resulting bar graph shows the errors color coded by machine. You can now click on the colored bars to explore what these errors were and then take action.

Installing Splunk

This is changing with every release, fortunately it get easier.

On Taro, Splunk is installed on /data/splunk/splunk-xxx with a link to the latest version. Taro also hosts the tar file.


Adding Forwarders

The process for installing a forwarder is pretty simple. Forwarders don't have a web interface, we turn it off, so use the following commands:

  1. cd /opt # (or /data for systems with a data drive)
  2. mkdir splunk
  3. cd splunk
  4. tar xzvf /net/data/taro/splunk/splunk-xxxx.tgx
  5. cd splunk
  6. bin/splunk start ## (agree to license)
  7. bin/splunk edit user admin -password splunkitnow -role admin -auth admin:changeme
  8. bin/splunk set deploy-poll 10.0.0.247:8089 ## (set deployment server as Taro)
  9. bin/splunk enable boot-start
  10. bin/splunk disable webserver
  11. bin/splunk restart

That's all folks.

Documentation

These links are useful references when setting up Splunk.

Download Splunk

Example Deployment server

Configure Deployment Clients (CLI examples)

Install on Linux

Deploy *nix Universal Forwarder

Change Admin pw from command line

Add files to monitor from command line

Retrieved from "https://nuclear.unh.edu/wiki/index.php?title=Splunk&oldid=5874"