IT Infrastructure (IT Infra)
Pulsar is a 20 IT guys company. The Pulsar infrastructure must support the internal general activities (email, domain authentication, network file sharing, website, DNS, etc.) as well as all other IT specific activities: development environments, huge and regular back-ups, technological investigations and prototypes, many OSs and servers types, virtualization, 3-Tiers architectures, different databases (Oracle, MySQL, PostGreSQL, SQL Server, etc), tens of millions of database transactions by months (Assurcard), industrial devices, etc.
The infrastructure activities include all operations needed to make everything function: installation and maintenance of servers, hosting databases and applications, back-up procedures, manage disk space, install IT environments, connecting devices, automatically.
Pulsar develops many web-based applications and websites and, in this respect, needs several servers for different purposes.
Some of these servers should be accessed by our customers in order to have a look at the work progress, perform acceptance tests, training sessions, demonstration during workshops, etc.
For security reasons these externally accessible servers are grouped on a dedicated sub-network. Also called DMZ (de-military zone), or Extranets (by opposition to Intranet, synonym to LAN), these sub-networks allow Pulsar key servers to be hidden/protected behind non-permissive firewalls.
The primary/default DMZ is the one of Pulsar. But we already set up such sub-networks (DMZ) for specific projects and/or specific customers like, for example, xNOTAM for Eurocontrol or Assurcard for Ardatis. This allows wrapping up customer’s specific environments into one dedicated DMZ, allowing giving more access rights on it to customers’ IT experts, when needed.
Pulsar develops different projects (standalone, heavy client, web & mobile) in different technologies, from very high level (Java, C#, .Net 4, iOS, Android, Windows Phone 7, etc.) to very low level (custom network protocols, embedded systems, etc.). In order to be compatible with all these technologies and with the clients’ environments, Pulsar works daily on multiple operating systems:
- Windows 2000, XP, Vista, 7, Phone 7
- Windows Server 2003 & 2008
- Linux Distributions (mainly Ubuntu Server and Debian)
- Mac OSX, iOS
The Pulsar’s methodology includes the setup of different environments in order to ensure a better project follow up. Moreover, all our maintenance contracts ensure to our customer the existence and maintenance of the following environments:
- DEVL – Development : exclusively for the development team
- TEST – Test environment : the development and Quality Assurance teams work together to test the application
- ACCEPT – Factory Acceptance Environment: the client’s team and the QA team work together to test and accept the application.
- PROD – Production-like environment: allows the QA team to reproduce the customer’s live environment for diagnosis purposes.
- TRAIN – training environment: used by the customer or by Pulsar following the training needs.
- LIVE – the production or live version of the application: Specific care to customer’s data must be given (backups, “don’t touch” policy, confidentiality, etc).
Maintenance and Hosting services
If a web application is maintained by Pulsar, SLAs (Service Level Agreements) are used to allow ensuring the following kind of services:
- Maintaining users in LDAP, including their organizations.
- Management of the access rights.
- Monitoring the IT Infrastructure and the servers’ availability and performances.
- Upgrading the technical characteristics of the infrastructure when needed (memory, processor, disk, virtual server, etc).
- Maintaining the data quality, taking daily data backups.
- Ensuring permanent availability of trained staff for second-line support and all types of interventions.
- Installing new versions of the applications.
- Ensure the specific tools training, knowledge transfer, and availability of necessary staff.
Those services allow customers to remotely connect to Pulsar’s infrastructure to follow up their application in different phases: development, test, acceptance, training, etc.
External Hosting - Cloud Solutions
Even if we have our own infrastructure, which is always used for the project development lifecycle (development, internal tests and acceptance tests), and generally for hosting the Live or Production environments, sometimes, specific requirements in terms of bandwidth, number of concurrent users, response time or availability, make that we must host the web site or application in a data center.
Offered by specialised hosting company, modern data centers are based on Dedicated Servers, accessible thru Internet by Remote Desktop Connection (securised access). The server, virtual or physical, is rented by Pulsar, and remotely managed by our IT Infrastructure Team, together with the project team. This allow us to use the same methodology, principles and teams, but take advantage of huge infrastructures in terms of server capabilities, disk space, processing speed, and Internet bandwidth.
Because of the mass effect, these hosting providers can offer excellent quality/price rate for these environments and services.
One of the most known in Europe, with the best quality/price rate, is the provider OVH, in France, which we use regularly.
The main parameters we pay attention in terms of server capabilities are:
- Processors: numbers and speed
- Memory: size and bus speed
- Disk: size and RAID function (duplicate stored information to face a disk crash without service discontinuity)
- Back-up service : full, incremental, differential, depending on the needs.
Example of a complex architecture using external hosting
This diagram shows a multi-site architecture connected over Internet. The externally hosted server manages the data storage, the business logic implementation and the general management of the system. Each distant site has its own intranet infrastructure connected to the central server through VPN.
The server also provides a VPN-free access (to limited resources) allowing mobile users to interact with the system. Those mobile users may be customers (on mobile devices or computer) or a distant System Administrator.