keeping simple

Author: vy

  • Data tiedowns with reliable time stamping

    Management teams are  growing more reliant on the ability to immediately  access and quickly sort through massive amounts of data to find the information they need – Data Governance for Financial Institution A “data tiedown” is a reliable and cross-checked timestamp that secures a data item or group of data items to one or more fixed…

  • Challenges upgrading time synchronization in a global financial company

    The real-world challenges of trying to upgrade time-synchronization without TimeKeeper are described in an excellent 2012 technical paper about a project at the company IMC Global Finance [IMC].  The article documents a two year, highly resourced project run by an expert engineering team – a nice data point for perhaps best case time synchronization using…

  • Time maps for visualizing time distribution networks

    Without this information, a time distribution network is a black box. TimeKeeper looks at all the sources of time, in any protocol, that it can see around it, and tracks each source back to its source. These maps, especially in larger and older firms, find all sorts of interesting things. They find “redundant” time sources…

  • Data integrity depends on time synchronization

    In a distributed compute system, such as any multi-device transaction system or database, time synchronization is essential to data integrity. The simplest case is a multi-step transaction over multiple compute devices – something that is common to a wide range of applications. Consider a financial trading application where machine A gets a tick containing a…

  • Efficient Optimistic Concurrency Control Using Loosely Synchronized Clocks

    Efficient Optimistic Concurrency Control Using Loosely Synchronized Clocks This paper describes an efficient optimistic concurrency control scheme for use in distributed database systems in which objects are cached and manipulated at client machines while persistent storage and transactional support are provided by servers. The scheme provides both serializability and external consistency for committed transactions; it uses…

  • Time Synchronization in the Cloud

    Synchronizing clocks in the cloud, especially for virtual machines, is way beyond the capabilities of ordinary synchronization methods. Tests show that virtual machines in the cloud relying on NTPd can fall off the reference time by tens of minutes over a single day. Even bare metal cloud platforms are significantly worse than dedicated machines.  This…

  • Mitre and GPS spoofing

    Some slides on GPS timing vulnerabilities.

  • The business case for being time protocol agnostic.

    Time Synchronization and Distribution is a business critical issue but it is easy to become bogged down in arcane technology/marketing controversies.  One of those controversies is over the choice between low level network protocols used to deliver time to application server computers.  The most widely used time synchronization protocol in the enterprise is called the…

  • Challenges deploying PTPv2 in a Global Financial company

    Interesting article – most of these problems and more were solved in TimeKeeper years ago. But the most interesting part is the enormous engineering effort required to kind of get PTP to work.

  • Patent Reform modest proposal.

    Companies over a certain size should be required to show that they have evaluated a patent claim from a small entity in good faith. That is, if they get a claim that they are infringing, they should be required to show in court that they looked at it seriously and tried to find out if…