Lazylogger
lazylogger is an application which decouples the data acquisition from the data logging mechanism. The need for such application has been dictated by the slow response time of some of the media logging devices (i.e. tape devices). Delay due to tape mounting, re-tension and re-positioning implies that the data acquisition has to be held until operation completion. By using mlogger to log data to disk in a first stage and then using lazylogger to copy or move the stored files to the "slow device", we can keep the acquisition running without interruption.
- Multiple lazyloggers can be running simultaneously on the same computer, each one taking care of a particular channel.
- Each lazylogger channel will have a dedicated ODB tree (see ODB /Lazy Tree ) containing its own information.
- All the lazylogger channels will be in the ODB under /Lazy/<channel-name>/...
- Each channel tree is composed of three sub-trees Settings, Statistics, List.
- Dynamic directory destination based on run number or date.
- Script copy support.
- Compression copy.
The Settings and Statistics trees are self-explanatory, and contain the operational parameters of the channel(s). The List key will have a dynamic list of run numbers which have been successfully dealt with by the lazylogger channel. This list won't exist until the first successful operation of the channel is completed. While the lazylogger was developed specifically for tape device, it also supports data file transfer to FTP repository system. Improvement towards a more generic support has been done which includes:
Arguments [-h ] : help. [-h hostname ] : host name. [-e exptname ] : experiment name. [-D ] : start program as a daemon. [-c channel ] : logging channel. Specify the lazylogger to activate. [-z ] : zap statistics. Clear the statistics tree of all the defined lazylogger channels.