Resource Centres OLA and Resource infrastructure Provider OLA reports
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Is is mandatory that EGI certified Resource Centres provide a minimum monthly availability and reliability as specified below (see the site-NGI Operational Level Agreement for details). Availability and reliability statistics (based on the global OPS VO) are issued on a monthly basis.
minimum availability | 70% |
minimum reliabilty | 75% |
Condition for suspension | Resource Centres which have an availability of less than 70% for three consecutive months will be suspended, i.e. removed from the production infrastructure. This will change to 70% from PY2 (May 2011 reports). Note. This suspension policy was reviewed in April 2011, and the original 50% threshold was increased to 70%. |
Condition for justification | Resource Centres not providing minimum monthly performance (70% availability, 75% reliability) MUST provide justification through a GGUS ticket. |
Performance reports
- Overview of availability and reliability statistics including suspended sites
- List of sites for which availability followup procedures were not applicable
2011
2010
EGI-wide Availability and Reliability
It is available here (xls file, data from May 01 2010)
Availability statistics per service/Resource Centre
Report generator
- (DEPRECATED) GridView availability/reliability report generator (providing access to the database including Nagios results for OPS and SAM results for VOs)
- ACE report generator
- ACE visualization portal
Process for quality verification
- Generation of statistics
Availability and reliability statistics are automatically generated the first week of the month by the Availability Computation Engine (Gridview until May 2011) in pdf format and placed under [1]. An Excel version is available at [2]
- Preliminary processing
Once the reports are generated, sanity checks are performed by EGI SA1 (Task TSA1.8). After this step is completed, statistics are uploaded into the EGI document server. Links to monthly statistics will be provided on a regular basis at this wiki page.
- Publication
An announcement of the new results is distributed by EGI SA1 (TSA1.8) to the NGI Operations Managers mailing list. COD (TSA1.7) is responsible of supervising statistics by chasing NGIs to chase sites that need to provide comments in case thresholds are not met, and identifies sites eligible for suspension. This phase starts by filing a ticket to the COD Support Unit. The overall comments gathering process is handled through tickets.
- Handling of sites below targets
For a site that misses availability/reliability targets but is not eligible for suspension:
- a child ticket is opened by the COD team and assigned to the respective NGI, asking for explanation to be given
- the explanation must be produced within 10 working days since the ticket is received by the site (please see known issues section [3]). Reminders and escalation is performed in accordance to COD escalation procedures [4].
- if the explanation is found satisfactory the ticket is closed
- conversely if the explanation is not given in due time, or the explanation is found inadequate, COD escalation procedure will be followed [5], with the site being suspended if neither site or NGI reply to the ticket
- the child ticket can then be closed
- the parent ticket will be closed when all child tickets have been closed.
- Handling of sites that are eligible for suspension
For a site that is eligible for suspension:
- a child ticket is opened by the COD team assigned to appropriate NGI, notifying that the site will be suspended within 10 working days (please see known issues section [6])
- after the 10 days period passes during which normal COD escalation procedures apply [7], the site is suspended by COD unless the NGI has intervened or the EGI Chief Operations officer objects.
- in the case of NGI intervention, non suspension will occur if both the COD and COO agree on the reasoning provided by the NGI
- the child ticket closes either when the site is suspended or when suspension is canceled
- the parent ticket will be closed when all child tickets have been closed
- Wiki follow up page
Sites that fail to provide explanations justifying the failure to meet OLA targets, or the explanation is found inadequate, as well as sites that are suspended, will be recorded in a wiki page [8]
Known issues and recommendations to NGIs
- Gridview is always calculating reliability and reliability of a site as soon as it shows up in GOCDB and in the BDIIs, regardless of its certification status. While processing the data in order to generate the availability/reliability report, GridView takes into account the Certification status of the site at that moment in order to decide if the site is certified and as a result it will show up in the report, or if it uncertified and it has to be excluded. Thus newly certified sites will get inaccurate Availability/Reliability figures for the month they were certified and all months before that. Because the Certification status history is not currently available in the operations tools, until a solution is implemented NGIs should check if they have sites affected by this issue and report it as explanation. More information at [9] and [10]. As of December 2010, Gridview has included a snapshot feature so availability takes into account the topology at the last day of the month. While it does not solve the problem completely, it reduces its impact. Currently (January 2011) it is used for the pdf reports generator but not for the Excel ones.
- The calculations performed by gridview always take into account the information system status and gocdb information at the time the calculation is performed, and not that of a certain checkpoint in the past. The implication of this is that any complete recalculation has the risk of altering the results for sites that had correct numbers in the first place. Thus until a solution is found, complete recalculations are avoided whenever possible, and errors are fixed on per site basis for those that have lower number than they should.
- Weighted availability is calculated by multiplying the number of logical CPUs a site published with the published HEPSPEC value. It is important that these numbers are correct, if HEPSPEC for a site is too high or too low (for example in case of mistake) the overall NGI wighted availability will be affected.
Resources
- Definition of Availability and Reliability and related computation algorithm (paper)
- NEW! List of Nagios tests used for availability computation
- Availability Computation Engine (ACE)
- Operational Level Agreement between NGI and site
- OLA release notes
- COD procedure for oversight of availability and reliability performance
- Impact of change of suspension policy for under-performing sites: report