BNL, Upton, Long Island, New York, USA
Proxy servers (Proxies) have been a staple of the World Wide Web infrastructure since its humble beginning. They provide a number of valuable functional services like access control, caching or logging. Historically, controls system have had little need for full fledged proxied systems as direct, unimpeded resource access is almost always preferable. This still holds true today, however unbound direct asset access can lead to performance issues, especially on older, underpowered systems. This paper describes an implementation of a fully transparent proxy server used to moderate asynchronous data flow between selected front end computers (FECs) and their clients as well as infrastructure changes required to accommodate this new platform. Finally it ventures into the future by examining additional untapped benefits of proxied control systems like write-through caching and runtime read-write modifications.
BNL, Upton, Long Island, New York, USA
Accelerator Device Object (ADO) specification and its original implementation are almost 20 years old. In those last two decades ADO development methodology has changed very little, which is a testament to its robust design, however during this time frame we've seen introduction of many new technologies and ideas, many of which with applicable and tangible benefits to control system software. This paper describes how some of these concepts like convention over configuration, aspect oriented programming (AOP) paradigm, which coupled with powerful techniques like bytecode generation and manipulation tools can greatly simplify both server and client side development by allowing developers to concentrate on the core implementation details without polluting their code with: 1) synchronization blocks 2) supplementary validation 3) asynchronous communication calls or 4) redundant bootstrapping. In addition to streamlining existing fundamental development methods we introduce additional concepts, many of which are found outside of the majority of the controls systems. These include 1) ACID transactions 2) client and servers-side dependency injection and 3) declarative event handling.
BNL, Upton, Long Island, New York, USA
There has been an increasing need over the last 5 years within the BNL accelerator community (primarily within the RF and Instrumentation groups) to collect, store and display data at high frequencies (1-10 kHz). Data throughput considerations when storing this data are manageable. But requests to display gigabytes of the collected data can quickly tax the speed at which data can be read from storage, transported over a network, and displayed on a users computer monitor. This paper reports on efforts to improve the performance of both reading and displaying data collected by our data logging system. Our primary means of improving performance was to build an Data Server – a hardware/software server solution built to respond to client requests for data. It's job is to improve performance by 1) improving the speed at which data is read from disk, and 2) culling the data so that the returned datasets are visually indistinguishable from the requested datasets. This paper reports on statistics that we've accumulated over the last two years that show improved data processing speeds and associated increases in the number and average size of client requests.
BNL, Upton, Long Island, New York, USA
For a number of years there has been an increasing desire to adopt a synoptic display suite within BNL accelerator community. Initial interest in the precursors to the modern display suites like MEDM quickly fizzled out as our users found them aesthetically unappealing and cumbersome to use. Subsequent attempts to adopt Control System Studio (CSS) also fell short when work on the abstraction bridge between CSS and our control system stalled and was eventually abandoned. Most recently, we tested the open source version of a synoptic display developed at Fermilab. It, like its previously evaluated predecessors, also seemed rough around the edges, however a few implementation details made it more appealing than every single previously mentioned solution and after a brief evaluation we settled on Synoptic as our display suite of choice. This paper describes this adoption process and goes into details on several key changes and improvements made to the original implementation – a few of which made us rethink how we want to use this tool in the future.