4. IT (Office) Platform Systems¶
4.1. System Scenario¶
This document describes exemplary solution implementations for an “IT (Office) Platform System” scenario. IT (Office) platform systems indicate shared platforms, such as those for authentication and file sharing, as it relates to IT systems used by internal corporate users for performing tasks; therefore, the following specific systems can be assumed as features:
- With this system, Customers can aggregate their servers which they utilize in office settings into one (1) integrated Cloud Service; specifically, following servers will be arranged in a typical scenario:
- AD (i.e., Active Directory) Server; i.e., focusing upon managing internal users and host administrations and permissions.
- WSUS (Windows Server Update Service) Server; i.e., focusing upon managing updates of internal Windows hosts.
- Anti-Virus Managing Server; i.e., focusing upon managing internal host’s anti-virus measures.
- File Server; i.e., internal shared file server.
4.2. System Configuration¶
This system, assuming implementation of DR (i.e., Disaster Recovery) measures in scenario, is configured from 2 geographically separate sites: the main site and the DR site. The system configurations for the main site and the DR site are described below.
4.2.1. Main Site¶
The main site accommodates the system during normal operation times, and configurations similar to the following can be assumed.
- Deployment of redundant IT platform servers.
- Installation of file servers of approx. 10TB.
Below is a diagram outlining the system configuration.
The main points of the configuration are described in the following sections.
4.2.1.1. Physical Level of Server Redundancy¶
Currently, it difficult to consider business activities without IT, and as such, each type of server used in configuration of IT platforms must have high reliability.
Generally speaking, Virtual Server provided by cloud services cannot be optionally designated to a physical host on which they will be stored. As such, even if redundancy is created through multiple Virtual Server there is a possibility that all will be stored on the same physical host. In cases where a failure occurs on the physical host, these redundant Virtual Servers will be suspended simultaneously, leading to a suspension of service. Virtual Servers can be optionally assigned during creation to a physical host equipment group (Group) on which the it will be stored. As a result, physical level of redundancy to ensure distribution of physical hosts for storage can be achieved through creating Virtual Servers on differing Groups for redundancy.
4.2.1.2. File Server¶
Redundant file servers are able to take redundant configuration through iSCSI mounting of volumes, provided by block storage, as a shared disk. Through this, service suspension times can be minimized during server maintenance.File server performance can be configured through storing with efficiencies at 2IOPS/GB.With regards to capacities, volume(s) can also be added depending on the usage status. Cost minimization can be achieved through utilizing the necessary amount at the necessary timing.
In view of backups, Customers are advised to obtain file system snapshots by utilizing Windows Server’s VSS (i.e., Volume Shadow-Copy Service).
4.2.2. DR Site¶
In cases where the IT platform server group stored at the main site is offline due to disaster, impacts occur such as inability to use the AD or file servers and tasks are suspended. As such, it is necessary to consider scenarios involving DR measures for building a DR site to quickly resume tasks. Here, an example system configuration will be introduced with the following features for low cost DR implementation:
- AD/File/WSUS servers etc. are configured and then launched at the DR site, replication is performed through a remote Inter-DC Network Connectivity, and most recent backup will be so utilized once load distribution is performed.
- Other WSUS servers, servers focused as managing anti-viral measures can be configured and activated if there is any actions worth taken for load distribution to undergo. In the event that Customers determine that there is no purpose as to distribute loads in DR site, then all they are required to store within will be ordinary volume(s) so that such will cut down the due cost.
Below is a diagram outlining the system configuration.
The main points of the configuration are described in the following sections.
4.2.2.1. Inter-Site Replication¶
When performing regular replication on the AD server between the main site and the DR site, traffic will be routinely generated between sites. The remote Inter-DC Network Connectivity will be utilized in order to process this replication traffic.
Furthermore, the DR site can be utilized for backup purposes through routinely performing a data sync with the DR site file server in order to prevent data loss due to physical failures etc. on the main site file server. Through this, load distribution and DR measures can be implemented at lower cost.
4.2.2.2. DR Site Cold Standby¶
When considering anti-virus servers that distribute definition files for internal client PCs, hot standby configuration is not necessary as there is some allowance for RTO (Recovery Time Objective) for servers which have purposes that do not immediately suspend tasks even when service is suspended.
After a unit of Virtual Server (Instance + Volume) is created / setup beforehand for cold standby configuration on the DR site side, instance billing can be minimized by setting that Instance to a suspended status. Service can be resumed during disaster recovery by booting the instance.
Additionally, instance billing can be reduced to 0 by deleting the instance from the Virtual Server that was setup on the DR site side, and setting the status to volume only. When in this status, billing will not be generated for the license service. Service can be resumed during disaster recovery by creating and booting an instance based on the volume. Although creating an instance during disaster recovery is somewhat time consuming, costs related to the standby Virtual Server will only involve volume billing, which enables a reduction in running costs.
Furthermore, image storage space can be used from creating an image of the volume. Running costs can be further minimized through this, but RTO will greatly increase as it will be necessary to perform restore processes from the volume image during disaster recovery.
