Verifying a Riak KV Installation

After you’ve installed Riak KV, we recommend checking the liveness of each node to ensure that requests are being properly served.

In this document, we cover ways of verifying that your Riak nodes are operating correctly. After you’ve determined that your nodes are functioning and you’re ready to put Riak KV to work, be sure to check out the resources in the Now What? section below.

Starting a Riak Node

Note about source installations

To start a Riak KV node that was installed by compiling the source code, you can add the Riak KV binary directory from the installation directory you’ve chosen to your PATH.

For example, if you compiled Riak KV from source in the /home/riak directory, then you can add the binary directory (/home/riak/rel/riak/bin) to your PATH so that Riak KV commands can be used in the same manner as with a packaged installation.

To start a Riak node, use the riak start command:

riak start

A successful start will return no output. If there is a problem starting the node, an error message is printed to standard error.

To run Riak with an attached interactive Erlang console:

riak console

A Riak node is typically started in console mode as part of debugging or troubleshooting to gather more detailed information from the Riak startup sequence. Note that if you start a Riak node in this manner, it is running as a foreground process that will be exited when the console is closed.

You can close the console by issuing this command at the Erlang prompt:

q().

Once your node has started, you can initially check that it is running with the riak ping command:

riak ping

The command will respond with pong if the node is running or Node <nodename> not responding to pings if it is not.

Open Files Limit

As you may have noticed, if you haven’t adjusted your open files limit (ulimit -n), Riak will warn you at startup. You’re advised to increase the operating system default open files limit when running Riak. You can read more about why in the Open Files Limit documentation.

Does it work?

One convenient means of testing the readiness of an individual Riak node and its ability to read and write data is with the riak admin test command:

riak admin test

Successful output from riak admin test looks like this:

Attempting to restart script through sudo -H -u riak
Successfully completed 1 read/write cycle to '<nodename>'

You can also test whether Riak is working by using the curl command-line tool. When you have Riak running on a node, try this command to retrieve the the properties associated with the bucket type test:

curl -v http://127.0.0.1:8098/types/default/props

Replace 127.0.0.1 in the example above with your Riak node’s IP address or fully qualified domain name, and you should get a response that looks like this:

* About to connect() to 127.0.0.1 port 8098 (#0)
*   Trying 127.0.0.1... connected
* Connected to 127.0.0.1 (127.0.0.1) port 8098 (#0)
> GET /riak/test HTTP/1.1
> User-Agent: curl/7.21.6 (x86_64-pc-linux-gnu)
> Host: 127.0.0.1:8098
> Accept: */*
>
< HTTP/1.1 200 OK
< Vary: Accept-Encoding
< Server: MochiWeb/1.1 WebMachine/1.9.0 (someone had painted it blue)
< Date: Wed, 26 Dec 2012 15:50:20 GMT
< Content-Type: application/json
< Content-Length: 422
<
* Connection #0 to host 127.0.0.1 left intact
* Closing connection #0
{"props":{"name":"test","allow_mult":false,"basic_quorum":false,
 "big_vclock":50,"chash_keyfun":{"mod":"riak_core_util",
 "fun":"chash_std_keyfun"},"dw":"quorum","last_write_wins":false,
 "linkfun":{"mod":"riak_kv_wm_link_walker","fun":"mapreduce_linkfun"},
 "n_val":3,"notfound_ok":true,"old_vclock":86400,"postcommit":[],"pr":0,
 "precommit":[],"pw":0,"r":"quorum","rw":"quorum","small_vclock":50,
 "w":"quorum","young_vclock":20}}

The output above shows a successful response (HTTP 200 OK) and additional details from the verbose option. The response also contains the bucket properties for the default bucket type.

Riaknostic

It is a good idea to verify some basic configuration and general health of the Riak node after installation by using Riak’s built-in diagnostic utility Riaknostic.

To start up Riaknostic, ensure that Riak is running on the node and issue the following command:

riak admin diag

More extensive documentation for Riaknostic can be found in the Inspecting a Node guide.

Now what?

You have a working Riak node!

From here you might want to check out the following resources: