Due to the digging and construction activity along the path between Near Disaster Recovery (NDR) in Mumbai BKC and the disaster recovery (DR) site in Chennai, the stock exchange faced instability in links from both service providers on February 24, it said.
National Stock Exchange (NSE) on March 22 said that it has removed the Storage Area Network (SAN) software following the link failure on February 24 which led to a halt in trading on the exchange between 10.06 am and 3.30 pm. Elaborating on its efforts to bolster the system, NSE said that it has been investing in its technology infrastructure on a continuous basis and over the last 3-4 years, it has almost tripled its annual cash spend on capital and operational expenses on technology to approximately Rs 900 crores.
The NSE added that the problem was caused by failover logic implemented by the vendor which did not conform to NSE’s stated design requirements, coupled with issues in the configuration done by the SAN vendor. The stock exchange even said that the specific failure logic used by the vendor was not communicated to NSE and was not appropriate for NSE’s setup, which led to the SAN failure.
The NSE says SAN is a fault tolerant system that was designed to function seamlessly even in the event of telecom link failures between primary and NDR copies. One of the features of SAN that was deployed in October 2020 was designed to provide not just zero data loss but also zero down time.