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Enterprise storage in harmony

There's nothing more important for an online exchange, than to provide its customers 24x7 access while sticking to the rigid regulatory norms laid down by SEBI. Here's how Refo-Sify implemented a mix-n-match, reliable and scalable storage solution to guarantee it customers zero downtime. by Soutiman Dasgupta

Refco-Sify Securities India Private Limited has to adhere to rigid set of regulations to protect its customers. After all a site that offers online and offline equity and futures trading for retail customers need to keep its socks pulled up all the time. It's the customer's money at stake. The company needed to offer 24x7 availability to its customers and stick to the regulatory norms laid down by SEBI (Securities Exchange Board of India). The norms require historical data to be continuously available for a specific period. The key to make all this happen was to get serious about data storage and establish a fool-proof enterprise storage solution.

The solution needed to be reliable, redundant, scalable, allow easy backup and recovery, and provide business continuity. After evaluating several data storage vendors, Manoj Chandiramani, Assistant Vice President, Networks, decided to use storage systems from Compaq and Sun. Solutions from the two vendors co-exist in harmony and provide real-time storage with facilities for backup and fail-over. "We can support growing numbers of users without the fear of losing critical financial data. The solution is built to support our needs for the next three years. And we have the flexibility to move to a SAN architecture in future", said Manoj.

The need to store
An online exchange should allow throughput in high-volumes and have little room for downtime. The solution has to be robust, reliable, and integrate well with the backend architecture. Since Refco-Sify decided to use Oracle 8i as the database, the storage needed to support the related applications as well.

"We decided not to use a server-based storage solution because you have to keep adding disks to the server as data volumes increase and it is not fool-proof. A cluster lets the system automatically switchover in case of disk failure. One can 'hot-swap' disks without interrupting the operations and still maintain integrity of the data. You can also create a logical partition in the same physical storage", pointed out Manoj.

Dual vendor harmony
Refco-Sify prefers to use a mix-n-match of solutions from Compaq and Sun. It uses Compaq's PL 5500R servers, PL 6400R servers, ML 330 servers, DL 380R servers, RAID Array 4100 storage boxes, Fiber Switches, ProLiant servers and Compaq PCs. And it uses Sun's E3500 servers, 220R servers, 250R servers, Array 1000 storage boxes, Array 5000 storage boxes, and Ultra servers. The storage applications are managed by Compaq StorageWorks Command Console and Microsoft Cluster Server software on Compaq boxes. Sun's boxes run proprietary storage software. There is a logical partition on each storage box to increase reliability.

The online exchange site uses e-commerce solutions from BroadVision. A proprietary order routing application called RORS is used to route orders to the stock exchanges.

The Compaq hardware runs Windows NT 4.0 Server as the NOS (Network Operating System) and the Sun hardware uses Solaris. The Oracle 8i database is run along with Oracle Fail Safe and Oracle Parallel Server. Oracle Fail Safe works with Microsoft Cluster Server to restart Oracle databases and applications on a surviving cluster node in the event of a system failure. And Oracle Parallel Server is an architecture that allows multiple instances to access a shared database.

The company used products from two different hardware vendors and two different NOSs to take advantage of the features offered by both. "We could have used Solaris on an Intel platform loaded on a Compaq box to give us the features of Solaris. But we wanted to use Sun's iPlanet as a Web server because it is a stable and strong product", said Manoj.

The storage boxes operate at RAID Level 5 and the network is designed to suit different configurations. This will help add servers and storage capacity in future. One can transform the existing storage configuration into a SAN (Storage Area Network) which will run on both NT and Solaris. The SAN can create a common pool of storage for the entire network.

Building storage and security
There was a team of vendors and solution providers that helped implement the network. Despite the herculean task to manage and coordinate the delivery schedules of the different vendors and consultants, the entire solution was up and running in 75 days. "We tested the performance of the system and discovered that it can login 500 simultaneous users and execute each request in less than a second. In case of a surge in data traffic during peak hours I can add additional hardware to support the load" declared Manoj.

Security solutions have been provided by Checkpoint. The applications run on Cisco hardware which is placed at the gateway level. This forbids unwanted access and data to be eliminated at the entry level.

Backup and recovery
Regulatory norms stipulate that transaction details should be available to clients for 90 days. SEBI (Securities and Exchange Board of India) may want to access a year's data anytime. And Refco-Sify has to preserve historical data for seven years. This means there should be adequate backup and recovery mechanisms to complement data storage.

Backup is taken on DLTs (Digital Linear Tapes). The company uses Compaq StorageWorks 40/80 and 35/70 and DLT drives from HP for its backup needs. Two sets of backup are maintained at the main office in Mumbai and at another remote location. "The remote location lies in a separate seismic zone," said Manoj. Backup is taken everyday at midnight since this is when traffic is the least and there is minimum downtime.

Recovery of data is facilitated by the use of server clusters. The advantage of a cluster solution is that if one server fails the others can take over automatically. If a hard drive in a server fails, it can be removed and new one put in its place without the box going down. "In the worst case, if all the clusters fail the site can be up and data can be recovered in 45 minutes by tweaking the system" promised Manoj.

Down the road
In future Refco-Sify wants to convert its enterprise storage solution into a SAN. "All I have to do is add a small component to the Compaq box to make it function in a SAN", said Manoj. This way, the company can offer additional services to its clients. And data stored at the site can be secure since it is inside the company's network and backups can be taken as usual.

The company wants to add more storage boxes to the network by April 2002. Currently, each storage box has a logical partition which allows the other partition in the same box to take over in case of failure. But what happens if the entire box fails? With more boxes in the network, a separate server can act as the fail-over.

"We do not have plans to migrate to Windows 2000 right away for the Compaq boxes. This is because we aren't sure whether we would get enough support and expertise from all our partners for a recently launched product. And NT 4.0 is able to support all the functions I need very well. We will only migrate if any feature we require is not supported in NT 4.0", explained Manoj.

"We would like to use robotic arms for our backup operations. Loading each DLT drive can be a painful task. You need to have a person at it all the time. Automating the process can save time and manpower", said Manoj.