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amazon-ec2datastax-enterpriseamazon-vpc

Time Service on Cassandra node in Private VPC Segment

I've installed 5 nodes on a private segment of an Amazon VPC. I'm receiving the following error when the nodes start:

These notices occurred during the startup of this instance:

[ERROR] 09/23/15-13:48:03 sudo ntpdate pool.ntp.org:

[WARN] publichostname not available as metadata

[WARN] publichostname not available as metadata

I was able to reaach out (through our NAT server) on port 80 to perform updates and log in to datastax. We're not currently using any expiration times in the schemas. I set the machines up without a public hostname,since they were only accessible through an API or by those of us in the VPN. All of the nodes are in the same availability zone, but eventually we will want to have nodes in a different zone in the same region.

My questions are:

  1. Is this a critical error?
  2. Should I have a public hostname on the nodes?
  3. Should they be on a public subnet (I would think not for security purposes)?

Thanks in advance.

Solution

  • I found in this:

    https://github.com/riptano/ComboAMI/blob/2.5/ds2_configure.py#L136-L147

    It seems to be the source of this message, and if it that's the case, it seems harmless -- a lookup of the instance's IP address is used instead of the hostname.

    If you aren't familiar with it, http://169.254.169.254/ as you will see in the code is a web server inside the EC2 infrastructure that provides an easy way to access metadata about the instance. The metadata is specific to the instance making the request, and the IP address doesn't change.