Mirroring or Proxying
HDP uses yum or zypper to install software, and this software is obtained from the HDP Repositories. If your firewall prevents Internet access, you must mirror or proxy the HDP Repositories in your Data Center.
Mirroring a repository involves copying the entire repository and all its contents onto a local server and enabling an HTTPD service on that server to serve the repository locally. Once the local mirror server setup is complete, the *.repo configuration files on every cluster node must be updated, so that the given package names are associated with the local mirror server instead of the remote repository server.
There are two options for creating a local mirror server. Each of these options is explained in detail in a later section.
Mirror server has no access to Internet at all: Use a web browser on your workstation to download the HDP Repository Tarball, move the tarball to the selected mirror server using scp or an USB drive, and extract it to create the repository on the local mirror server.
Mirror server has temporary access to Internet: Temporarily configure a server to have Internet access, download a copy of the HDP Repository to this server using the reposync command, then reconfigure the server so that it is back behind the firewall.
![[Note]](../common/images/admon/note.png)
Note Option I is probably the least effort, and in some respects, is the most secure deployment option.
Option III is best if you want to be able to update your Hadoop installation periodically from the Hortonworks Repositories.
Trusted proxy server: Proxying a repository involves setting up a standard HTTP proxy on a local server to forward repository access requests to the remote repository server and route responses back to the original requestor. Effectively, the proxy server makes the repository server accessible to all clients, by acting as an intermediary.
Once the proxy is configured, change the /etc/yum.conf file on every cluster node, so that when the client attempts to access the repository during installation, the request goes through the local proxy server instead of going directly to the remote repository server.