Dell DX6000 Manuale introduttivo - Pagina 12

IN A

192.168.1.103

In the preceding example, it is important that the time to live (TTL) value for each of the records in

the round-robin group is very small (0-2 seconds). This is necessary so that clients that cache the

resolution results will quickly flush them. This allows for the distribution of the node of first contact

and allows a client to quickly move on to another node if it tries to contact a failed node.

Although it is recommended that applications implement more robust mechanisms like zeroconf

for distributing the node of first contact and skipping failed nodes, an administrator can use DNS to

assist with less sophisticated applications.

2.3.3. Preparing for Named Objects

For users to be able to access named objects over the Internet, you must enable incoming HTTP

requests to resolve to the correct domain. (A cluster can contain many domains, each of which can

contain many buckets, each of which can contain many named objects.) Cluster and domain names

should both be IANA-compatible host names like cluster.example.com and are discussed in

more detail in the DX Object Storage Administration Guide.

For example, a client application can create an object with a name like the following:

cluster.example.com/marketing/photos/ads/object-naming.3gp

In this example, cluster.example.com is the domain name, marketing is the name of a

bucket, and photos/ads/object-naming.3gp is the name of an object. You must set up your

network so the host name in the HTTP request maps correctly to the object's domain name. (The

cluster name is not important in this regard.)

To enable users to access the preceding object, you must set up one of the following:

• Set up your hosts file to map domain names to IP address(es) of the node of first contact.

For a Linux system, configure /etc/hosts

For a Windows system, configure %SystemRoot%\system32\drivers\etc\hosts

A sample hosts file follows:

192.168.1.111

192.168.1.112

• Define multiple DNS entries (that is, "A" or "CNAME" records) that specify the IP address(es) of

the DX Storage node of first contact.

Specifying multiple IP addresses for a DNS entry creates a DNS round-robin which provides client

request balancing.

For more information about setting up DNS for DX Storage, see

for Name

Resolution".

For details about setting up your DNS server, consult your DNS software documentation.

DX Storage exposes monitoring information and administrative controls through SNMP. An SNMP

console provides an administrator a mechanism with which to monitor a DX Storage cluster from

a central location. See the SNMP appendix in the DX Object Storage Administration Guide for

additional information. The SNMP MIB definition file for DX Storage is located as follows:

cluster.example.com

vault.example.com

Section 2.3.2, "Setting Up DNS

December 2010

Version 5.0