Hardware Setup

Mission: Management Computer Services’ (MCS) mission is ensuring that PHA-Web is available 24 hours a day, 365 days a year. We understand that it is mission critical for our clients to access data stored and managed by PHA-Web. Because any single system is capable of failure, MCS designed and implemented a fully redundant system that eliminates single points of failure.

Physical Security: Primary PHA-Web servers are placed in a SSAE-16 certified collocation facility in Massachusetts. It is a secure location for warehousing Internet servers that is staffed 24 hours a day. Authorized personnel may enter the building only by presenting a photo ID. After checking in, access is gained by passing through a series of secure doors. Each area of the data center, and each row within the data center, is monitor by closed circuit surveillance cameras at all times. PHA-Web servers are locked inside a private cabinet within this facility.

Power Reliability: To ensure maximum power reliability, the collocation facility provides dual dedicated 4000 Amp power feeds as well as a 1500 Amp DC power plant. For brief power outages, four 5000KVa Powerware UPS systems are available to provide continuous power. If an extended power outage occurs, three 2.2 Megawatt diesel generators are available to power the facility indefinitely.

Internet Service Reliability: The collocation facility utilizes multiple T3 or greater Internet connections from multiple Tier 1 Internet Service Providers including AT&T, Verizon, VerizonBusiness (MCS/Worldcomm), Expedient, Lightower Dark Fiber, Cogent Communications, Veroxity and others. Bandwidth is delivered via redundant fiber optic entrances into the data center eliminating single points of failure with respect to connectivity.

The on-site Network Operations Center (NOC) is staffed all day, every day, by trained technicians and IT professionals. NOC’s staff monitors Internet connection integrity and performance thereby allowing the collocation to quickly and proactively resolve concerns before they become customer service issues.

Environmental Reliability: To ensure computer equipment is maintained at safe operating temperatures, the collocation facility employs 28 Airflow Computer Room Air Conditioning units providing over 450 tons of cooling with four 12 fan dry coolers in an N+1 configuration.

Sensitive equipment in the data center is protected from fire damage by a state-of-the-art Viking 3-stage fire suppression system with a Very Early Smoke Detection Apparatus (VESDA) in 14 zones.

Server Reliability: PHA-Web servers utilize a highly redundant architectural design. All servers feature RAID 1, RAID 5 or RAID 10 hard drive arrays, multiple processors, dual network cards, and redundant power supplies. Additionally, PHA-Web uses an industry standard virtualization platform. Virtualization allows a physical server to host multiple virtual servers. This allows greater flexibility in responding to performance needs or hardware failures.

Service Reliability: PHA-Web is not hosted on one single server; several clusters host PHA-Web. A cluster is a logical grouping of multiple servers that act as one. In the event a server within a cluster fails, the remaining server(s) assume the failed server’s workload to continue providing service from that cluster. See the picture on this page for a rack view of the servers and other hardware

Services for PHA-Web are divided into three groups: application, reporting and database. A three server cluster manages the database service. The application and reporting services are managed by virtual servers. Additional virtual servers provide email, management, and backup services for PHA-Web. These virtual servers are hosted on a cluster of eight physical machines.

Data Reliability: In addition to multiple servers containing multiple hard drives in various RAID arrays, all PHA-Web data is backed up periodically and stored in two separate geographical locations. Backups are stored at the collocation facility as well as MCS’s office. Full backups are performed weekly, differential backups performed nightly and transaction log backups performed every 15 minutes.

Conclusion: PHA-Web’s hardware setup virtually eliminates every possible single point of failure. The redundancy and security levels provided by the collocation facility, MCS’s servers, server clusters, network, and backup infrastructure are far greater than what is normally used, or can reasonably be provided, by an individual housing authority for traditional onsite server based applications. All of this means PHA-Web is much more reliable and secure than traditional in-house servers.