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From Allen Servedio <allen.serve...@gmail.com>
Subject Ec2Snitch and Ec2MultiRegionSnitch - does us-west-2 cause a bug with this snitch?
Date Mon, 14 Nov 2011 14:01:28 GMT
Hi,

As of Nov. 9, 2011 Amazon added us-west-2 (US West Oregon) region:
http://aws.typepad.com/aws/2011/11/now-open-us-west-portland-region.html

In looking at the EC2Snitch code (in the 0.8.x and 1.0.x branches), I see
it determining which data center (which I think is supposed to be
equivalent to region) it is in by this:

public Ec2Snitch() throws IOException, ConfigurationException
    {
        // Split "us-east-1a" or "asia-1a" into "us-east"/"1a" and "asia"/"1a".
        String[] splits = awsApiCall(ZONE_NAME_QUERY_URL).split("-");
        ec2zone = splits[splits.length - 1];
        ec2region = splits.length < 3 ? splits[0] : splits[0] + "-" + splits[1];
        logger.info("EC2Snitch using region: " + ec2region + ", zone:
" + ec2zone + ".");
    }


The Ec2MultiRegionSnitch then has this reconnect logic - which I think the
existence of a us-west-1 and us-west-2 regions and the way the Ec2Snitch is
assigning data centers will cause this to break:

    private void reConnect(InetAddress endpoint, VersionedValue versionedValue)
    {
        if (!getDatacenter(endpoint).equals(getDatacenter(public_ip)))
            return; // do nothing return back...

        try
        {
            InetAddress remoteIP = InetAddress.getByName(versionedValue.value);
            MessagingService.instance().getConnectionPool(endpoint).reset(remoteIP);
            logger.debug(String.format("Intiated reconnect to an
Internal IP %s for the %s", remoteIP, endpoint));
        } catch (UnknownHostException e)
        {
            logger.error("Error in getting the IP address resolved: ", e);
        }
    }

Am I correct or do I not understand what was intended by these snitches?

Allen

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