Originating Author: David Floyer
The classic components of a service level agreement (SLA) are availability and response time. In the case of storage services, the availability of the service for (say) a transaction system is measured as a percentage (e.g., 4 nines or 99.99%) and response time would be measured as average IO time in milliseconds (e.g., 10ms).
However, at the in-line compression Peer Incite a number of the benefits to the user were not captured by traditional SLA metrics. Some examples from the call include:
- Freshness of data – Shopzilla can update the shopping comparison data six times a day, whereas its competitors can update once every two days
- Backup window length – the impact of the IBM Real-time Compression is to reduce the amount of data actually stored by 50%, which reduces the amount of data that has to be backed up (data in compressed form does not have to be re-hydrated until the application actually requires it). The reduction in backup window pressure for Shopzilla was 1.5 hours. The impact of this is to help the application to be available to different time zones around the world. For the developers it means an additional 1.5 hours of time when effective work could be done.
- Business Risk – the reduction of backup window length reduces the RPO of disaster recover services. However, the insertion of compression also increases the risk of data loss by introducing an additional technology. For Shopzilla, the long term benefits of in-line data compression outweighed any short term risk from introducing a new technology.
Action Item: In evaluating any significant change to storage services, IT executives should ask the question “does the proposed change to a storage service positively affect the ability of the end-users (employees and/or partners and/or customers) to perform their jobs. In the case of Shopzilla, in-line data compression improved the value of IT to the business.
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