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I'm trying to build a new Cassandra cluster on Amazon EC2 using Opscenter for development use.

I have installed Opscenter (v4.1.3) on an EC2 instance using the instructions on, and followed the instructions in to build a two-node cluster. The node is not directly accessible from the public internet; I have configured an httpd rule on our NAT box to forward traffic to the opscenter install.

However, when I hit "Build Cluster" I get an error pop-up saying "Error checking provisioning requests: Unable to load /opscenter/request/[object Object]/status status: 404"

Wireshark shows that my laptop is indeed doing a get for "/opscenter/request/[object%20Object]/status" and "[object Object]" looks to me like some Javascript should be inserting the contents of an object, so I believe this is a fault in the Javascript.

I've had a scan through the source as served by Opscenter, but it is all minified. I shall have a look through the source tarball tomorrow.

Any help gratefully received at this point.

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It seems the problem was in forwarding traffic through our NAT box. My forwarding rules were rather naive and there is clearly some traffic not being forwarded.

I created a new CentOS 6 EC2 instance with direct visibility from the internet, and set up the security groups and iptables to allow access to port 8888. Opscenter now gets much further.

I did try running opscenter on our NAT box, however I got Python errors. I believe this was due to the NAT box not running a Linux flavour supported by Opscenter.

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"Error checking provisioning requests: Unable to load /opscenter/request/[object Object]/status status: 404" – That is definitely a bug. For reference, I've created a ticket in our internal tracker: OPSC-2996. I've also linked to this discussion and will make sure this thread is updated when the bug is fixed. Thanks for your feedback. I'm glad to hear that you discovered the NAT issues and were able to work around it despite this bug. – Thomas Upton Jun 24 '14 at 19:25

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