April 30th, 2007
We were sad to read at the end of last week that grid.org, which for the last seven years has been using the volunteered spare CPU cycles to search for a cure to cancer. They’ve said that they have completed their mission to prove the viability of large-scale public internet based grid computing. The equivalent of over 3000 years of computing time was donated making it the largest public project ever held.
There are though other projects still running. We know from personal experience the horrors of being diagnosed with cancer; if you can please subscribe one of the on-going projects. The more we all do the faster we’ll fully understand the mechanisms that cause cancer, and equally how we can more quickly cure it.
April 30th, 2007
Since Peer Software released their latest product, Peer DRS, in mid-April we’ve had numerous questions asking what DRS is all about and what it can do to help protect a company’s SQL Servers. After all, SQL Server has its own replication so why would you want Peer DRS. In this respect the answer is very simple; if you want SQL Server replication you need enterprise licenses and these don’t come cheap. If you’re a large firm then the extra cost may not be a issue, but for smaller firms the higher initial and on-going costs hurt budgets, and year on year.
We’re asked almost every week; I need a solution so I can have two databases at two locations. From the remote site users only need to read their local copy of the database, no updates. Prior to Peer DRS the only solution was get yourself some enterprise licenses. Not now. One way of running Peer DRS allows you to distribute your data and make it available read only. How up to date would you like that other copy? Up to the last minute be OK? Now you can run your reports against the copy and save network bandwidth.
The number of different ways that you can use Peer DRS is quite stunning:
- One-to-One Standby Replication
- Many-to-One Standby Replication
- One-to-Many Standby Replication
- One-to-One File Copy
- One-to-One File Copy Multiple Location
- Clone to same server
April 17th, 2007
Purple Rage, a UK distributor of software solutions for Windows, Linux and Mac OSX, announces the release of Peer Software’s Peer DRS. Peer DRS delivers centralised database backup and replication, with changes being transmitted to one or more remote locations. The initial release supports Microsoft SQL Server; future releases will support other database platforms (Microsoft® Exchange®, MSDE, MySQL, etc.).
Peer DRS is an application which provides a framework for automating the replication of databases and incremental changes from primary servers. Replicated data is then restored onto one or more target standby servers. Transaction logs are automatically backed up throughout the day which are then automatically restored on standby servers located anywhere in the world. Through continuous data protection Peer DRS is able to deliver the resilience companies need for their database applications, even in the most diverse environments. Peer DRS is highly configurable to meet the needs of almost any backup scenario.
Paul Marsala, CEO of Peer Software said, “Peer DRS was developed to meet an unaddressed need: centralising and simplifying the replication of an organisation’s databases, wherever they may reside. Peer DRS has a plug-in architecture allowing it to support different types of database backups from a single application. As with all our backup and synchronization tools, Peer DRS combines enterprise-grade functionality with ease-of-use. Once configured, it will manage all database replication routines with nominal administration.”
- Support for MS SQL Server 7.0 (limited support), MS SQL Server 2000 and MS SQL Server 2005.
- Perform up to the minute incremental backups and replicate them to one or more warm standby databases.
- Configure and manage all database backups and replication remotely from a central, client-based GUI.
- Replicate across a WAN via FTP, SFTP, SSH or a password protected Network Shared drive.
- Cross platform Java based application that can run on various operating systems such as Windows, Linux, Mac, etc.
- Able to use the standby server as a live read-only database.
- Send alert emails if connection to primary database cannot be established or if a backup or restore has not occurred within a configurable period of time threshold.
- Report on all replication activity in real-time from a single control panel allowing for easy identification of current errors or for peace of mind by knowing everything is operating smoothly
About Purple Rage Limited
Purple Rage was founded in 2005 by Rob Dixon and Jan Gregson. Purple Rage is a UK & European Distributor, formed to create a platform for a focused set of solutions to meet the requirements of company’s evermore demanding, diverse and heterogeneous environments. By working with strategic partners that promote and enhance multiple operating systems we are able to serve diverse business sectors. For further information: http://www.purplerage.com
About Peer Software Inc
Founded in 1993 by Paul Marsala, “Peer Software, Inc.’s mission is to offer utilities that centralize management of critical computer processes across your entire business enterprise”. Their goal is to promote data consistency, ensure against data loss, and facilitate software distribution, desktop monitoring, knowledge transfer, and a host of activities designed to sustain seamless business communications and improve operating efficiencies.
April 4th, 2007
In part one of this article I outlined the need for a proper solution to protect SQL Server. In this part I’ll cover some of the main ways in which you can go about achieving different measures of protection and as a consequence, increased availability.
Which option works best for you is very much dependant on what version/edition of SQL Server you’re running. The level of protection and availability you attain is then largely governed by the needs of your company, and especially by the size of your budget. The bottom line is this; the more you spend, the greater the degree of availability.
- SQL Server in Microsoft Cluster
- Replication and fail-over software
- Replication software
- Backup software
The ultimate method of providing availability with the minimum of impact on users and client applications has to be by using at least two copies of SQL Server Standard or Enterprise running in a Microsoft Cluster. A RAID array shared between the nodes gives both access to the data stores irrespective of which machine is hosting the resources groups. “Virtual servers” are created that all SQL Server instances are accessed through by users and applications. Now it doesn’t matter which physical SQL Server is alive, the user or application only ever sees the virtual server. If one server is down all transactions are automatically processed by the other server, completely transparently. This method does though involve a lot of expenditure, and server node location is limited by the available network link speed to the attached 2+ nodes and the shared storage. So this option may not be ideal or even possible in a very distributed environment.
If budgets really cannot run to total availability, third-party software is a very viable alternative. The end result from their use is varying degrees of availability from minutes to hours. The choice as to which is the most appropriate is likely to be driven be how much you are prepared to compromise availability in the environment in which the protected systems must run. However, the one element that should never be compromised is the quality of storage used; RAID-5 or RAID-10 should always be used to give the best balance of redundancy and speed.
A product like EMC’s RepliStor doesn’t give you perfect 100% availability of all servers, transactions and data stores, but with its ability to replicate all data in real-time, across WAN or LAN networks, interact with the Virtual Shadow Service (VSS) and self validate the replicated data, it manages to come very close. A product like RepliStor doesn’t have any of the limitations of distance that you’d get in a cluster. By using aliases it is able to provide not just replication over local and wide area networks but also fail-over. The result is a backup server could be operational within a a very short period of time, and with just about the latest transactions.
Alternatively you could use a product like PeerSync to take scheduled “snapshots” of SQL Server every 30 minutes, hour, whatever you want. With its utilisation of St Bernard’s Open File Manager built into the product it’s able to take fully functional copies of logs and data stores, with little likelihood of any repairs being needed prior to them being put live from another system. By adding the “ByteReplicator” module to the standard offering, only the changes in a snapshot are replicated not the whole thing all over again. This saves time, network resources, and permits the target of the replication to be just about anywhere in the country/world. The down side; on failure you’d lose all transactions since the last snapshot.
Lastly there’s good old backup software. Traditionally not really an availability application, but like PeerSync can be made to provide a very workable solution. By running a backup periodically during the day to online media like a NAS box you get the equivalent of PeerSync “snapshots”, but all the data at that point in time rather than a consolidation of just the differences. The draw back with a lot of backup solutions is having to go back to the most recent full, restore the incrementals, then you’re back in business. By using EMC Retrospect though every backup is an incremental. The result, upon restore you choose the date and time of the restore point and Retrospect builds the image ready for restore. Much faster and efficient. The downside is the time to recover and the loss of all transactions after the last backup was taken.
In conclusion, a company needs to evaluate its business needs and the degree to which it is prepared to compromise its own data stores and inputs. Whatever the result, there is more often than not a solution to meet requirements. Purple Rage is well placed to supply those solutions through its network of partners and consultants in the UK and Europe. For more information we can be reached on +44-(0)871-2500058, or via email at email@example.com.
April 2nd, 2007
Your licensing requirements for SQL Server 2005 in virtual machines are very much determined not by the type of virtual machine that you’re using, but by the hardware it runs on. This means that if you want to run SQL Server Standard, Workgroup, and Enterprise, and you decide to license on a per processor basis, you must buy a SQL Server license for each virtual processor. Furthermore, for Enterprise Edition, you can also choose to license all the physical processors on the server. Doing this gives you the right to run SQL Server on an unlimited number of virtual processors running on that single machine.
If you’ve chosen to use the Server/CAL mode (for Standard and Workgroup), then you have to have licenses for each virtual machine in which SQL Server runs. However, if you have an Enterprise Server license for the physical server then you can run SQL Server in any number of virtual machines on that same machine.
There’s a very informative whitepaper on Microsoft’s website on this whole subject if you want to learn more. If you want to trial running SQL Server in a virtual machine why not try Parallels Desktop or Workstation. Both are freely available from Purple Rage.