WELCOME TO FRONTIER

The Frontier system distributes data from central databases that are read by many client systems around the world. The name comes from "N Tier" where N is any number and tiers are layers of locations of distribution. The central database is located at Tier 0, which distributes data to to all the Tier 1, Tier 2, and Tier 3 sites around the world. Within each site the Frontier system also distributes the data to all the worker nodes (typically hundreds or thousands) that need to use the data. The protocol is http-based and uses a RESTful architecture which is excellent for caching. The Frontier system uses the standard web caching tool squid to cache the http objects at every site. The Frontier system was developed for the CDF experiment at Fermilab and is heavily used there. Fermilab also adapted Frontier for the CMS experiment at the Large Hadron Collider at CERN and it is used to access "conditions data" at all its sites worldwide. The ATLAS experiment at the LHC has also adopted Frontier to access conditions data at all its Tier 2 and Tier 3 sites.

Source code and other project information for frontier client and frontier server (implemented as a tomcat servlet) is freely available under the GNU LGPL license (mostly). Here are instructions for deploying squid for CMS and instructions for deploying squid for ATLAS.

These are the CMS Frontier monitoring systems: Overall status Detailed statistics for central servers (awstats) Graphed statistics for all worldwide squids (MRTG) Graphed statistic summaries for major sites and tiers (MRTG) Service Level Status of CERN central servers (SLS) Service Level Status of CERN T0 squid servers (SLS) Availability status at grid sites worldwide (SAM) (select All Sites and tests CE-cms-frontier and CE-cms-squid and click Show Results) Experimental detailed plots of CERN central servers: today, yesterday, all MRTG plots are also accesible through this widget. These are the ATLAS Frontier monitoring systems: Detailed statistics for central servers (awstats) Graphed statistics for all worldwide squids (MRTG)

For more information about Frontier visit the CMS DatabaseAccess TWiki page. A paper describing the use of Frontier in CMS is available here and another one describing its efficient cache consistency strategy is available here. Information on the old CDF Frontier project is available on its Wiki page.

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Last updated: Thu Nov 5 16:35:41 CET 2009