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I have Graphite setup on three instances on EC2:

  • carbon-relay -
  • carbon-cache + webapp -
  • carbon-cache + webapp -

The relay is working perfectly with consistent-hashing. The problem is the two web servers are not communicating with each other, so I only see the metrics from one server.

I spent a lot of time looking at and I can't figure out what I have setup incorrectly. I can run a wget from cache3 against cache4, get data back and see it in the Apache logs. So I don't think it's a firewall issue. I tried enabling suppressError = False in and turned on DEBUG in, but I don't see any errors in Firebug.

cache3 -

CLUSTER_SERVERS = [ '', 'localhost' ]

cache4 -

CLUSTER_SERVERS = [ '', 'localhost' ]

I have tried using IP addresses as well and that had no impact.

I did a little more debugging and modified to directly hard code my remote hosts:

STORE = Store(settings.DATA_DIRS, remote_hosts=["", ""])

That worked. So, somehow my CLUSTER_SERVERS value isn't getting pulled in from correctly.

Any suggestions?

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up vote 1 down vote accepted

Turns out the permissions on were too restrictive and Apache was unable to read it:

-rw------- 1 root root  4006 May  4 13:40

Fixing the permissions to 644 (instead of 600) resolved the problem.

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