Health Check monitor

Since July 2008 VLT/VLTI data are transferred over the internet to the Garching NGAS archive. From there they are retrieved by QC Garching. Calibration data have a very small delivery delay, often just a few minutes. QC Garching attempts to process new calibration data within one hour, in order to derive crucial information about the health of the instruments. That information is derived in form of QC1 parameters. For these parameters, scores are derived, an evaluation against configured thresholds.

The Health Check monitor collects QC1 parameters and their scores. It does not aim at completeness but is focusing on the critical information components. The results are presented in two views: the graphical HEALTH CHECK monitor with the full reports (more ...), linked by default, and the QUICK-LOOK monitor with scores (less ...).

The Health Check monitor is a component of the real-time QC system. Its other main components are the calChecker (calibration completeness), and the AB product monitors with the complete set of products, QC1 parameters and scores for a given date.

Process. The Health Check process is fed by calibrations which measure key instrument components ("health check calibrations"). They are taken regularly, in many cases daily. They are pipeline processed by QC Garching by an automatic process which is triggered every hour. The pipelines derive QC1 parameters which are stored in a database. Some more advanced QC1 parameters are derived by post-pipeline QC procedures and added to the database. These most recent values are trended, that means plotted together with a historical data set (often the last 90 days).

Scoring. The trending is supported by scoring, where a new parameter set is evaluated against configured thresholds. These thresholds can be fixed values (e.g. specifications), or relative values (like +/- 10% around the mean which is calculated from the trending), or statistical values (like +/- 3 sigma around the mean).

Opslog data. A second data set is included here, namely the QC1 parameters as derived from the Paranal on-line pipelines. These data are collected in opslog files and transferred via ftp. They are included here as a fall-back solution in case of problems with data transfer. The Paranal QC1 parameters could differ from the final values as determined by the Garching pipelines because they are derived with default processing values, a static calibration database etc.

OPSLOG files are delivered to, and evaluated by QC Garching once per hour. Whenever a new entry is detected, the corresponding Health Check plot is updated. The health of the ftp process is monitored by a small java application:

	ftp
	parser

Check out here possible actions in case of alerts.

Trending plots. The Health Check monitor offers access to all kinds of trending plots:

• Health Check plots: the ones compiling the QC1 values for the most important and regularly measured instrument components (marked by in the horizontal navigation bar) and including OPSLOG data,
• similar ones without OPSLOG data (marked no OPSLOG data) (because e.g. the pipeline does not produce them),
• plots with data which are only infrequently measured (driven by science data and the calibration plan),
• the QUICK-LOOK reports with instrument scores (linked under less ... )
• the complete available historical set (linked under history).

QC1 database. You can download the QC1 parameters, and also link to the QC1 database. Most plots have a corresponding tutorial page linked as tutorial.

The process behind the Health Check Monitor is documented in more detail here.