SQL Anywhere OnDemand (SAODE) allows database administrators to quickly set up and administer SQL Anywhere databases in the cloud, as high-availability services. Once the initial supported cloud environment has been configured (three cloud servers running as the two cloud partners and the cloud arbiter), administrators often have occasion to add additional hosts to their cloud. The SAODE software has a few specific requirements for the hosts both for installation purposes and production scenarios. These system requirements must be met to maintain a healthy and stable cloud. This document goes through the preparation necessaryto ensure that a host is ready to be added to the cloud with a main focus on the Microsoft Windows Operating Systems.
A majority of the configuration for the cloud requires running OS-level tasks that require full privileges. Without these privileges, the cloud administrator is unable to run the necessary installs and ultimately cannot add additional hosts to the cloud. Ensure that the Windows Account has full Administrator privileges.
There are two install types that determine the host name in the cloud.
If Single use is chosen, then a host name is required that restricts the executable from running on any host except the one specified. This is also the host name displayed in the cloud.
If Multiple use is chosen, a list of IP addresses can be used to restrict the target hosts. However, the computer name of each target is the host name displayed in the cloud.
Since there is potential for having a significant number of hosts in the cloud, ensure that all hosts have meaningful computer names. This makes remote viewing sessions easier and also makes managing hosts in the Cloud Console simpler.
The Windows Firewall ensures that all hosts are secure. However, it is also vital that cloud hosts are able to communicate with each other and that cloud servers are both reachable and secure. This requires specific rules to be created/configured on the host itself to allow access to the TCP ports associated with the cloud through the firewall. More information here: http://technet.microsoft.com/en-us/library/cc947814(v=ws.10).aspx
When a cloud is first configured, three cloud servers must be converted to two cloud partners, and one cloud arbiter. Note that the cloud servers then permanently inherit the ports they are currently running on. Other cloud servers dynamically choose their ports every time they are started.
For this reason, keep all cloud ports and ranges that are chosen when adding the host available for inbound connections through the firewall. If the firewall is blocking any vital connections, then a rule must be set up to unblock that port, or, if necessary, allow specific connections from individual hosts. If the cloud ports aren’t reachable, the install wizard warns that the port may be in use, but it is good practice tocheck all ports beforehand and keep them clear.
During the process of adding a host, the user is given the opportunity to change the location of the software as well as the data directory. These decisions are important since the cloud may require plenty of storage space for storing cloud system information (i.e. the cloud Infrastructure).
The software directory is where all cloud software is installed. This directory can hold multiple versions, so ensure that it is on a disk with enough space. The cloud software is either from the initial cloud install, if it’s the first host to be added, or it is sent from another host in the cloud.
The data directory is slightly different as its size can vary greatly over time. One of the reasons for this variation is that the data directory contains the cloud infrastructure, log files, and tenant databases. Make sure to place this directory on a drive where disk space is not a problem.
Add Host Demonstration
The following is a demonstration of adding additional hosts to a cloud. This host has the necessary ports open using inbound rules as well as sufficient space for both the software and data default directories.
- Connect to the cloud using the Cloud Console: https://Host-Name:Port/dbcloud/
- On the left pane, click Hosts and then Create host install:
- A new window should open displaying the Create Host Install form. The first provided option is for the Host install type.
- Single Use: This form generates an executable to be run only on the single host that was provided in the host name field.
- Multiple Use: This executable can be run on multiple hosts before the expiration date.
Choosing Multiple Use prompts the Valid for (days) option. The default is one week and can be left as is. Once this expiry period has concluded, the executable is no longer valid and another executable must be generated to add additional hosts.
There is also the functionality to restrict the add host executable to specific hosts. If Restricted is chosen, then a list of IP addresses of potential hosts can be included. For this demonstration, leave the Unrestricted option selected.
- The next option is the Install version. Select a software version from the dropdown menu. The dropdown menu is populated from the list of downloaded cloud software visible in the Cloud Console under Cloud software. Ensure you pick the appropriate software (32 or 64bit).
- Once the Install version is chosen, the form is populated with options for the Installation directories, Server ports, and After installation.
- As mentioned previously, specify target directories that have enough space available for both the software as well as the data.
- Software Directory: When the host is first added, the software is installed to this directory.
- Data Directory: This directory always holds tenant databases as well as the cloud infrastructure. Any software versions downloaded later are placed in the data directory on the primary host and can then be copied to other hosts.
- Server ports should be configured with care. See earlier section “Firewall Configuration” for more details on how to ensure host communication remains both secure and functional.
- The After installation option simply chooses to create and start a cloud server after the host has been added. If this option is unchecked, the user must manually create/start a cloud server on this host. By default, this option is checked and can be left as is for this demonstration.
- Click Create and Download. This generates and saves the executable with the selected options. Using the above options, this executable can be run on multiple hosts for seven days. The executable itself does not contain the cloud software but actually accesses the least busy host holding a copy of the targeted software.
- Finally, place the downloaded executable on any target hosts and run it as the administrator. Provide the necessary credentials and the executable adds the host to the cloud and creates and starts a cloud server on that host. Lastly, the Cloud Console can be checked to confirm success.
Different operating systems, hardware, and networking capabilities can cause issues that may differ from the discussed items above. This guide is designed specifically to help with the most common and well-known issues at hand. For more information on each section, please see the online help documentation for assistance.