High Availability Solutions

Availability refers to the term where a service or an application is found to be available on the situation when users expect. It is through the perception of the end user of an application that availability is measured. When data becomes unavailable, it provides a lot of frustration for an end user. It should be mentioned that the same havoc is created when there are performance failures because of the higher than expected usage occurs. The most three characteristics of a highly available solution are reliability, recoverability and continuous operations. When you look forward to a full range of HVA solutions, it can be the best thing to contact us as we provide with the best work ranging from simple clustering solutions to high end multiple location cluster solutions. So, we strive to provide with the best platform in order to meet all the important and different needs and requirements of the business.

When it comes to the expression of availability, it is expressed numerically. For example, for a period of one year for a requirement for 99.9 percent availability allows 8.75 hours of downtime. In other words, the availability of a requirement for 99.9 percent helps in permitting only 40 minutes downtime every four weeks for maintenance. The relationship between some common server availability targets and amount of downtime on an annual basis has been illustrated in the Table 1.

Table 1 Server Availability and Permitted Downtime
Availability Target Permitted Annual Downtime
99% 87 hours 36 minutes
99.9% 8 hours 46 minutes
99.99% 52 minutes 34 seconds
99.999% 5 minutes 15 seconds

In order to increase the availability of a system there is another type of clustering which is quick migration. It is seen to be used with server workloads and applications in the perfect manner which is normally not cluster-aware.

There is a combination of Windows Server 2008 Hyper-V hypervisor-based virtualization with failover clustering in Windows Server 2008 Enterprise and Windows Server 2008 Datacenter with Quick Migration. It is possible to run server workloads on virtual machines when it comes to quick migration. There is a configuration on each host server as a node in a failover cluster. If there is a failure in the virtualized workload that is hosted by the initial server then hosting is done by another server in the cluster. It is possible for you to get the work done on the first server and then try to resume support services in the best way without any problem at all.

In order to increase the availability of a system there is another type of clustering which is quick migration. It is seen to be used with server workloads and applications in the perfect manner which is normally not cluster-aware.

There is a combination of Windows Server 2008 Hyper-V hypervisor-based virtualization with failover clustering in Windows Server 2008 Enterprise and Windows Server 2008 Datacenter with Quick Migration. It is possible to run server workloads on virtual machines when it comes to quick migration. There is a configuration on each host server as a node in a failover cluster. If there is a failure in the virtualized workload that is hosted by the initial server then hosting is done by another server in the cluster. It is possible for you to get the work done on the first server and then try to resume support services in the best way without any problem at all.

Individual servers are kept highly available with the help of reliable hardware. It is found that only the workloads are kept highly available by other high availability strategies. There are built features in Microsoft in order to enhance high availability into SQL Server, Microsoft® Office SharePoint® Server and Exchange Server in order to keep running your system in the best manner.

The most critical components are mailbox databases and the contents of its data of any Exchange organization. Mailbox databases can be protected with the help of Microsoft Exchange Server 2013. This is possible as it configures your mailbox databases for site resilience and high availability. It also goes a long way in reducing the cost with the help of Exchange 2013. By supporting large mailboxes, it provides higher levels of end-to-end availability. Thus it helps in a good way in deploying economically a messaging continuity service by the customers.

SQL Server high-availability solutions make it possible in improving the availability of servers or databases. It helps a lot in masking hardware effects as well as failure in software thereby maintaining the applications availability so as to minimize the perceived downtime for users.

There are lots of different options provided by SQL Server to create high availability for a server or database. The following are included in the high availability options:

Failover clustering

Failover clustering helps in providing with then best as well as high availability support for SQL server.


Database mirroring

Being a software solution, database mirroring helps a lot in increasing database availability where it supports all types of instantaneous failover as well.


Log shipping

The mechanism of log shopping is same as that to database mirroring where it operates at the database level. Maintaining one or more warm standby databases for a corresponding production database is possible with the help of log shopping.


Replication

When it comes to replication, it uses publish-subscribe model. Distribution of data takes place to one or more secondary servers from the primary server. Scalability and real time availability is enabled by replication.


Scalable shared databases

Read-only database is scaled by the scalable shared database feature. It is built exclusively for reporting. For primary purpose of hosting the database, it is a on a set of dedicated, read-only volumes that the reporting database must reside in the perfect way.


Oracle Database offers the most comprehensive set of HA capabilities and so it is uniquely positioned in the industry. It is available with a single product. Capabilities such as:

  • Real Application Clusters (RAC),
  • Data Guard, Automatic Storage Management (ASM),
  • Flashback,
  • Recovery Manager (RMAN),
  • Online Reorganization, Edition-based Redefinition, etc.

are found to be available in the Oracle Database as built-in features. These capabilities work together in an integrated manner along with complementary products such as Oracle Secure Backup and Oracle Golden Gate. So it helps in providing with the best solution for Oracle Database that helps a lot in reducing as well as eliminating planned as well as unplanned downtime at the perfect manner as well.

In order to keep businesses running with less downtime from unplanned outages, CA ARCserve High Availability software serves to be much useful. It helps in making the process easier for continuous data protection. When it comes to your most critical applications and data, high availability is provided that includes SQL Server, SharePoint, Microsoft Exchange, Internet Information Services (IIS) and Oracle and BlackBerry servers. It is also possible to protect Linux and UNIX servers, Windows, application and data for both physical and virtualized server environments in your data center. It is also possible to complement backup solution that in turn provides a more comprehensive strategy for the protection of data as well as system availability.